Health Supervision for People With Achondroplasia · Achondroplasia is an autosomal dominant disorder, meaning a person with achondroplasia has a 50% chance of passing the condition

CLINICAL REPORT Guidance for the Clinician in Rendering Pediatric Care

Health Supervision for PeopleWith AchondroplasiaJulie Hoover-Fong, MD, PhD, FACMG,a Charles I. Scott, MD, FAAP,b Marilyn C. Jones, MD, FAAP,c COMMITTEE ON GENETICS

abstractAchondroplasia is the most common short-stature skeletal dysplasia,additionally marked by rhizomelia, macrocephaly, midface hypoplasia, andnormal cognition. Potential medical complications associated withachondroplasia include lower extremity long bone bowing, middle-eardysfunction, obstructive sleep apnea, and, more rarely, cervicomedullarycompression, hydrocephalus, thoracolumbar kyphosis, and central sleepapnea. This is the second revision to the original 1995 health supervisionguidance from the American Academy of Pediatrics for caring for patients withachondroplasia. Although many of the previously published recommendationsremain appropriate for contemporary medical care, this document highlightsinterval advancements in the clinical methods available to monitor forcomplications associated with achondroplasia. This document is intended toprovide guidance for health care providers to help identify individual patientsat high risk of developing serious sequelae and to enable intervention beforecomplications develop.

The original “Health Supervision for Children with Achondroplasia” policyfrom the American Academy of Pediatrics (AAP) in 1995 provided usefulmanagement recommendations to pediatricians caring for children withachondroplasia from birth through early adulthood.1 The first revision in2005 expanded the scope of the document to include new informationabout the molecular genetics of achondroplasia and improvements inanticipatory guidance in terms of prevention and treatment ofcomplications of the condition.2 The majority of the information providedin those documents remains pertinent and accurate in the current careof patients with achondroplasia. This revision highlights additionalinterval advancements in the clinical methods available to monitor forcomplications associated with achondroplasia, including adult healthcomplications that may be rooted in childhood and should, therefore, bemonitored and managed from birth. This document also incorporatesa few of the more recent treatment options for achondroplasia to providean informational core from which the general pediatrician can explore

aGreenberg Center for Skeletal Dysplasias, McKusick-NathansDepartment of Genetic Medicine, Johns Hopkins University School ofMedicine, Baltimore, Maryland; bNemours/Alfred I. duPont Hospital forChildren and Sidney Kimmel Medical College, Thomas JeffersonUniversity, Wilmington, Delaware; and cDepartment of Pediatrics,University of California, San Diego and Rady Children’s Hospital, SanDiego, California

Drs Hoover-Fong and Scott wrote new content and edited content fromthe previous AAP statement and responded to reviews; Dr Jonesprovided editorial and content review, shepherded the documentthrough multiple stakeholders review, and addressed specificconcerns; and all authors approved the final manuscript as submitted.

Clinical reports from the American Academy of Pediatrics benefit fromexpertise and resources of liaisons and internal (AAP) and externalreviewers. However, clinical reports from the American Academy ofPediatrics may not reflect the views of the liaisons or theorganizations or government agencies that they represent.

The guidance in this report does not indicate an exclusive course oftreatment or serve as a standard of medical care. Variations, takinginto account individual circumstances, may be appropriate.

All clinical reports from the American Academy of Pediatricsautomatically expire 5 years after publication unless reaffirmed,revised, or retired at or before that time.

This document is copyrighted and is property of the AmericanAcademy of Pediatrics and its Board of Directors. All authors have filedconflict of interest statements with the American Academy ofPediatrics. Any conflicts have been resolved through a processapproved by the Board of Directors. The American Academy ofPediatrics has neither solicited nor accepted any commercialinvolvement in the development of the content of this publication.

DOI: https://doi.org/10.1542/peds.2020-1010

Address correspondence to Julie Hoover-Fong, MD, PhD. E-mail:[email protected]

PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275).

Copyright © 2020 by the American Academy of Pediatrics

To cite: Hoover-Fong J, Scott CI, Jones MC, AAP COMMITTEEON GENETICS. Health Supervision for People WithAchondroplasia. Pediatrics. 2020;145(6):e20201010

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additional resources with patients.The authors recognize the audiencefor this document may have variablemedical resources at their disposal tomonitor and treat patients withachondroplasia. The intent of thisconsensus document is to provideguidance that may be adapted to eachindividual patient in his or her uniqueenvironment. Children andadolescents with achondroplasiashould have care coordinated througha medical home; however, some ofthe surveillance and counselingsuggested in this document will beprovided by a number of specialistswith expertise in the management ofachondroplasia, if these individualsare available.

Achondroplasia is the most commoncondition associated with severe,disproportionate short stature, withan estimated birth incidence of 1 in10 000 to 1 in 30 000.3,4 Thereis no recognized ethnic or sexpredisposition. The diagnosis canusually be made on the basis ofclinical characteristics and specificfeatures on radiographs, includinga square shape of the pelvis witha small sacrosciatic notch, shortpedicles of the vertebrae withinterpedicular narrowing fromthe lower thoracic through lumbarregion, rhizomelic (proximal)shortening of the long bones,proximal femoral radiolucency, anda characteristic chevron shape of thedistal femoral epiphyses. Otherclinical features include short stature,macrocephaly (absolute and relative),trident configuration of the hands,and long, near-normal-length trunk.

Achondroplasia is an autosomaldominant disorder, meaning a personwith achondroplasia has a 50%chance of passing the condition on toeach of his or her offspring regardlessof the sex of the parent or child,provided the other parent isunaffected. Approximately 75% to80% of patients with achondroplasiaare born to average-stature parents,representing a new dominant

mutation in the fibroblast growthfactor receptor type 3 (FGFR3) genein that affected individual.3,5,6

Because virtually all of the causalmutations occur at exactly the samenucleotide within the gene,6 genetictesting for achondroplasia isstraightforward. It is not necessary toperform molecular testing in everychild with a clinical diagnosis ofachondroplasia. However, FGFR3testing should be considered whena confirmed achondroplasia diagnosisis needed. For example, infants orchildren with an atypicalachondroplasia presentation mayhave a second genetic condition.7

Such children also should be referredfor clinical genetics evaluation.Different mutations in the FGFR3gene can also cause 2 other shortstature dysplasias:hypochondroplasia andthanatophoric dysplasia. A child withhypochondroplasia has the sameclinical features as one withachondroplasia, as listed above, butmilder overall. Growth hormonetherapy may be considered asa treatment option for those withhypochondroplasia, but it has notbeen shown to be effective inpatients with achondroplasia.8–11

Thanatophoric dysplasia usually canbe distinguished from achondroplasiaand hypochondroplasia becausesevere thoracic and lung hypoplasiaare expected to be lethal in the pre- orearly postnatal period in the former.12

Rare exceptions of a patient withthanatophoric dysplasia surviving arereported but only with aggressivemeasures of resuscitation at deliveryand significant respiratory supportthereafter.13,14 Age-specificrecommendations pertaining togenetic counseling and testing arealso included in each age categorydiscussed later in this report.

A great deal is known about thenatural history of achondroplasia thatcan be shared with the family.4,15

The average adult height inachondroplasia is approximately 120

to 135 cm (4–4.5 ft) (Fig 1).16 Themost common complication,occurring in adulthood, is related tolumbosacral spinal stenosis withcompression of the spinal cord ornerve roots.17–19 This complication isusually treatable by surgicaldecompression, with less sequelae iftreated at an early stage. Mostchildren with achondroplasia do well.However, children affected withachondroplasia commonly havedelayed motor milestones(Fig 2),20–22 otitis media, and bowingof the lower legs.23 Less commonly,infants and children may have serioushealth consequences related tocraniocervical junction compressionbecause of a relatively small foramenmagnum, hydrocephalus, upper-airway obstruction, or thoracolumbarkyphosis. Although they are lesscommon, anticipatory care shouldinclude identifying children at highestrisk and intervening to preventpotentially serious sequelae. Mostindividuals with achondroplasia areof normal intelligence and are able tolead independent and productivelives.24 Because of theirdisproportionate short stature,however, a number of psychosocialproblems can arise.25 Chronic pain,a problem that may begin inchildhood and magnify intoadulthood without intervention, maybe playing a larger role in overall lifesatisfaction and coping than has beenpreviously appreciated.26 Furtherinvestigation is needed to betterunderstand the temporal relationshipamong pain, function, and medical orsurgical treatment to allow for thehighest quality of life possible.Families can benefit from anticipatoryguidance and the opportunity to learnfrom other families with children ofdisproportionate short stature. Theconsensus-based guidance in thisreport is designed to help thepediatrician care for children withachondroplasia and their families.Issues that need to be addressed atvarious ages are outlined in Table 1.

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It should be noted that thesesuggestions are not appropriate forother skeletal dysplasia diagnosesbecause each type has its own naturalhistory, complications, and specificmanagement recommendations. Themost recent nosology of geneticskeletal disorders includes 436different disorders with primary bonemanifestations, and more than half ofthese are considered to be skeletaldysplasias.27 Because of the vastrange of medical considerations forpatients with these diagnoses, it isimportant that pediatricians and their

patients partner with a physicianwith special experience and expertiseconcerning skeletal dysplasias,particularly achondroplasia, early inthe child’s life. This report providesgenerally applicable suggestions thatmust be tailored to a particular child’scondition and needs. For reference,the American Board of MedicalGenetics and Genomics has an onlineresource to search for a certifiedgeneticist throughout the UnitedStates and in several countriesaround the world (http://www.abmg.org/pages/searchmem.shtml).28

Similarly, the Little People of America,Inc, the largest US patient supportgroup for short-stature skeletaldysplasia patients and their families,may be a suitable resource forinformation for medical providersand families (http://www.lpaonline.org/).29

In addition to the age group–specificguidance presented in this report, 3topics often arise in early discussionswith families about potentialtreatment of achondroplasia: growthhormone therapy, surgical limblengthening, and, more recently, drugtrials for new medications to alterbone morphology and growth. Thefollowing is not meant to be anexhaustive review of these issues butrather a brief foundation on whichfurther discussions can be built.

First, in reference to supplementalgrowth hormone treatment, therehave been longitudinal studies ofrelatively small groups of patientswith achondroplasia treated withgrowth hormone of various doses anddurations.8–11 A recent meta-analysisof 12 trials showed a clinicallyinsignificant increase of –5 to –4 SDbelow the mean when children withachondroplasia were treated withgrowth hormone.10 Some authorsalso suggest that the rapid (althoughunsustained) linear growthpredisposes to worsening scoliosisand kyphosis in these patients.10 Incontrast, a few studies have showna greater adult height in patients withhypochondroplasia treated withgrowth hormone therapy.8 As notedpreviously, genetic testing would beuseful to differentiate these 2conditions before embarking ona long and expensive course ofsupplemental growth hormonetreatment.

With respect to limb lengthening,there is a body of medical literatureaddressing different surgical methodsof lengthening, complications of theprocedures,30 perspectives onlengthening the upper extremities,31

FIGURE 1Fifth, 50th, and 95th percentiles for height for children with achondroplasia (solid lines) comparedwith height growth curves for the general population (dotted lines), based on 1955 observationsfrom 162 boys and 131 girls with achondroplasia. Adapted from Hoover-Fong JE, Schulze KJ,McGready J, Barnes H, Scott CI. Age-appropriate body mass index in children with achondroplasia:interpretation in relation to indexes of height. Am J Clin Nutr. 2008;88(2):364–371. Curves for the USpopulation are from Kuczmarski RJ, Ogden CL, Guo SS, et al. 2000 CDC Growth Charts for the UnitedStates: Methods and Development. Hyattsville, MD: National Center for Health Statistics; 2002. Il-lustration is from Growth References. Third edition. 2011. Permission for use was granted by theGreenwood Genetic Center.

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and reviews of the entire process.32

Opinions about the use and success ofsurgical limb lengthening vary widely.Regardless of a patient or family’sposition, however, it is important forthe pediatrician to be aware of a fewkey issues surrounding surgical limblengthening. Limb lengthening isa long and costly process, associatedwith significant physical pain for theyoung patient. The age at which thisprocedure is recommended variesamong surgeons, but implementationbefore epiphyseal closure is the norm,with many encouragingcommencement at younger than10 years. Medical decision-making inthis age group rests with the parentor legal representative who couldmake a decision without involving thechild in the discussion. Per AAP policyon informed consent,33 it is highlydesired that the child and parentsengage in discussion about suchelective procedures before a decision

is made. Finally, this procedure isassociated with complications.Therefore, it is critical that thesurgical team is readily available tomanage short- and long-termcomplications associated with limblengthening.

The last novel issue to address is thepharmaceuticals under developmentto potentially increase long bonegrowth and/or ameliorate the skeletalcomplications of this condition. Thereare several compounds currently atvarious stages of development withdifferent targets andmechanisms.34,35 More informationabout these trials can be found onlineat https://clinicaltrials.gov. The trialprocess often takes several years, andfinal approval is required from the USFood and Drug Administration fora new drug to become availablethrough a prescription. For familiescontemplating enrollment of their

child with achondroplasia in one ofthese trials, it is important to knowthat a physician conducting a clinicaltrial should have sufficient experiencewith the condition to differentiatecomplications (or a response) toa research pharmaceutical from thenatural history of that condition.

THE PRENATAL VISIT

Pediatricians may be asked to counselexpectant parents whose fetus hasachondroplasia or is suspected tohave achondroplasia because ofrecognition on ultrasonography ofdisproportionate small stature andrelative large head size. In somesituations, the pediatrician may bethe primary resource for counselingthe family. At other times, counselingmay already have been provided tothe family by a clinical geneticist,genetic counselor, or maternal-fetalmedicine specialist. Because ofa previous relationship with thefamily, however, the pediatriciancould be called on to review thisinformation and assist the family inthe decision-making process.

The diagnosis of achondroplasia inthe fetus is made most often withcertainty when one or both biologicalparents have this condition. In thiscircumstance, the parents are usually(but not always) knowledgeableabout the disorder, the inheritance,and the prognosis for the offspring.However, specific inquiry about thepresence of a short stature diagnosisin both parents is recommendedwhen only the mother is present forthe clinical visit and may notspontaneously offer that her partneralso has short stature. Additionally, itis important to establish clearly thespecific short stature diagnosis inboth parents. If both parents haveachondroplasia, for example, reviewof the potential outcome of this andeach future pregnancy (25% averagestature, 50% achondroplasia, 25%homozygous or “double dominant”and, therefore, lethal) is

FIGURE 2Developmental screening tests in achondroplasia, based on questionnaire information from 197individuals. The bar scale reveals the percentage of children with achondroplasia passing the item.The black triangle on top of the bar reveals the age at which 90% of normal children pass the sameitem. Illustration is from Growth References. Third edition. 2011. Permission for use was granted bythe Greenwood Genetic Center.

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straightforward. In the situation inwhich one parent has achondroplasia

but the partner has a differentdysplasia diagnosis, the recurrence

risk discussion must be tailored totheir specific diagnoses and

associated inheritance. Often, there islittle medical literature available to

reference and anticipate the medicalcourse of a compound heterozygousoffspring. Ideally, such genetic

counseling should be provided bygenetic medicine professionals, such

as genetic counselors and/or clinicalgeneticists.

Most often, the scenario presentswhen the diagnosis of achondroplasiais suspected late in gestation on thebasis of long bone foreshorteningincidentally discovered viaultrasonography in the fetus of anaverage-stature couple. It is rare forultrasonographic features ofachondroplasia to be noticeablebefore 26 weeks’ gestation, althoughBoulet et al36 reported a new prenatal

ultrasonographic diagnostic sign forachondroplasia they named the

“collar hoop” sign, which may beevident earlier. If long bone anomalies

and/or disproportion are appreciatedearlier in gestation, a skeletal

dysplasia more severe thanachondroplasia is likely.37 Higher-

level ultrasonography andexamination for other diagnosticfeatures are then required.

Confirmation of diagnosis on thebasis of ultrasonographic features

TABLE 1 Health Supervision for People With Achondroplasia

Prepregnancyand

Short-StatureParents

Prenatal and Short-and

Average-StatureParents

Birth to1 mo

1 mo to 1 y 1–5 y 5–13 y 13–21 y Adult

DiagnosisPhysical examination X X of fetus X X — — — —

Imaging X radiographs X ultrasonography offetus

X — — — — —

Molecular testing X X of fetus X — — — — XGenetic counselingReview natural history X of potential

offspringX X X X X X X

Recurrence risk and genetics X X X X X X X XDelivery mode and location X X — — — — — XSupport group(s), family support X X X X X X X XDesired pregnancy? — X X — — — — X

Medical evaluationGrowth (height or length, weight,

occipitofrontal circumference)— X X X X X X X

Physical examination — — X X X X X XNeurologic examination — — X X X X X XDevelopment — — X X X X — —

Neuroimaging — — X X if newdiagnosis

X asindicated

X asindicated

X asindicated

X asindicated

Polysomnography — — X X if newdiagnosis

X asindicated

X asindicated

X asindicated

X asindicated

Hearing assessment — — X X X X X XRadiography for kyphosis, genu

varus, bowing— — — X X as

indicatedX as

indicatedX as

indicatedX as

indicatedAnticipation or guidanceWarning signs of severe

complications— — X X X X X X

Car seats — X for hospitaldischarge

X X X X — —

Achondroplasia-specificdevelopment

— — X X X — X —

Jugular bulb dehiscence warning — — — X X X X XSupplemental security income

inclusion— — — X X X X X

Accommodations — — — — X X X XObesity, exercise, diet — — — — X X X XDriving — — — — — — X XCollege — — — — — — X XJob training — — — — — — X X

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characteristic of achondroplasia canbe provided by molecular testing(FGFR3 mutational testing) ofprenatal specimens (chorionic villussampling at 11–13 weeks’ gestationor amniocentesis after 15 weeks’gestation). Typically, this would beperformed at a specialized prenatalcenter. If no such confirmation forachondroplasia (or any otherdysplasia) has been completed,caution should be exercised whencounseling the family.

Prenatal consultation involvinga couple in which one or both carrya skeletal dysplasia diagnosis and areseeking genetic counseling andanticipatory guidance is best arrangedbefore pregnancy.38 Typically, this visitwould be with a medical geneticist orgenetic counselor. In this scenario,there is ample time to confirm theparental dysplasia diagnoses andevaluate the woman (if she is shortstature) for neuraxial complications orprevious surgical procedures, whichcould influence anesthesia options fordelivery (ie, general versus spinal orepidural).

Depending on the prenatal situation,the pediatrician may consider thefollowing steps as needed:

1. Review, confirm, anddemonstrate laboratory orimaging studies leading to thediagnosis.

2. Explain the mechanisms foroccurrence of achondroplasia inthe fetus and the recurrence riskfor the family, depending on thepresence of a dysplasia in both,one, or neither of the parents.

3. Explain that up to 80% ofpatients with achondroplasia areborn to average-stature parents.In these affected children, theirachondroplasia occurred becauseof a spontaneous mutation in theFGFR3 gene. In this situation,recurrence risk is empiricallyapproximately 1% for futurepregnancies for this specific

couple because of the possibilityof gonadal mosaicism.

4. Review the natural history andmanifestations ofachondroplasia, includingvariability.4,15

5. Discuss additional studies thatcould be performed in thenewborn period to confirm thediagnosis (eg, blood test formutation in FGFR3, radiographsto review for achondroplasia-specific features). If miscarriage,stillbirth, or termination occurs,confirmatory testing is importantif the woman or family desiresoptimal genetic counseling. Ifspecific molecular testing cannotbe offered immediately, try tosecure a blood or tissue samplefor future testing.

6. Review currently availabletreatments and interventions,including efficacy, complications,adverse effects, costs, and otherburdens of these treatments.Discuss possible futuretreatments and interventions.Please see the medical evaluationand anticipatory guidancediscussions in the sectionson health supervision forchildren ages 1 month to1 year, 1 to 5 years, and 5 to13 years.

7. Explore the options available tothe family for the managementand rearing of the child by usinga nondirective approach. In casesof early prenatal diagnosis, theseoptions may include discussionof pregnancy termination,continuation of pregnancy andrearing of the child at home,foster care, or adoption. Ifadoption is planned, the LittlePeople of America, Inc, hasadoption resources available(http://www.lpaonline.org/adoption).39

8. If the pregnant woman carriesthe diagnosis of achondroplasia,inform her that a cesarean

delivery will be necessarybecause of the characteristicsmall pelvis and cephalopelvicdisproportion (regardless ofwhether the fetus is averagestature or has achondroplasiaalso and, therefore,macrocephaly). Prenatalconsultation with a high-riskmaternal or fetal medicinespecialist is recommended toinvestigate whether generalanesthesia or spinal or epiduralanesthesia will be needed fordelivery. In an average-staturepregnant woman carrying a fetuswith achondroplasia, a cesareandelivery may also, but not always,be necessary because of fetalmacrocephaly.

9. Establish where the infant withthe suspected (or possible)skeletal dysplasia diagnosis willbe delivered. Pediatric services tomanage potential medicalcomplications at or shortly afterdelivery may be necessary andare not available at all hospitals.

10. When both parents are ofdisproportionate short stature,assess the possibility of the fetusinheriting both conditions.Infants with homozygousachondroplasia usually arestillborn or die shortly afterbirth.40

11. Be aware that many of thesediscussions will be coordinatedwith the prenatal team, includinga medical geneticist, geneticcounselor, and/or maternal-fetal medicine specialist. Theimportance ofa knowledgeable medical homefor the expected infant should bereviewed.

HEALTH SUPERVISION FROM BIRTH TO1 MONTH OF AGE: NEWBORN INFANTS

Diagnosis, Genetic Counseling

1. Confirm the diagnosis byradiographic studies in thenewborn period. External physical

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features may not be highly obviousfor achondroplasia. Radiographsshould include anteroposteriorand lateral skull, anteroposteriorand lateral cervical spine,anteroposterior and lateral chestand abdomen with pelvis andupper femurs,anteroposterior of each upper andlower extremity long bone, andanteroposterior of hands and feetseparate from long bones.Molecular studies may be pursuedif desired.

2. Discuss genetics of achondroplasiawith the parents, including thefollowing:

a. Autosomal dominantinheritance: Any person withachondroplasia will have a 50%chance of passing this conditionon to each offspring, regardlessof the sex of the parentand child.

b. Approximately 80% of childrenborn with achondroplasiarepresent spontaneous newmutations in the FGFR3 gene.

c. Germ-line mosaicism (in whichsome germ cells are derivedfrom a normal cell line andsome are from a cell line witha mutation, also known asgonadal mosaicism) has beenreported in families withachondroplasia. This meansthat 2 average-stature parentshave had more than 1 childwith achondroplasiaattributable to gonadalmosaicism. The recurrence riskof achondroplasia in sporadiccases via gonadal mosaicism isapproximately 1%.41–43

d. Recurrence risk when bothparents have a skeletaldysplasia diagnosis should alsobe reviewed.

3. Recognize the potentialpsychosocial implications for bothparent and child related to shortstature.

a. Refer the family to a supportgroup, such as Little People ofAmerica.39

b. If parents do not wish to joina group, offer meetingindividually with other affectedindividuals or parents.

c. Discuss how they will tell theirfamily and friends about theirchild’s diagnosis.

d. Refer to other supportresources, such as clergy, socialworkers, and psychologists.

e. Remind parents that mostpeople with achondroplasialead productive,independent lives.

f. Supply the parents witheducational books andpamphlets (http://www.lpaonline.org/).29

g. Discuss the realistic functionaldifficulties for affectedindividuals.

Medical Evaluation

1. Measure and plot total bodylength, weight, and occipitofrontalcircumference on achondroplasia-specific growth charts (Figs 1 and3–5)16,22,44 at birth and everyhealth supervision visit. Reviewthese growth parameters withboth parents.

2. Use achondroplasia-specificdevelopmental charts at everyhealth supervision visit(Fig 2).20,22

3. Assess every infant withachondroplasia for craniocervicaljunction risks as soon as thediagnosis is recognized45 via thefollowing:

a. Careful neurologic history andexamination. This includesinquiry about feeding ability,choking or gagging withfeeding, prolonged apnea whilesleeping, cyanosis of lips ormouth with feeding or sleeping,symmetry of limb movements,

and axial andappendicular tone.

b. Polysomnography (overnightsleep study, evaluated bya pediatric pulmonologist,including end tidal carbondioxide in addition to standardmeasures of apnea, hypopnea,saturation) to assess forunusual central apnea.

c. Neuroimaging, provided it canbe performed safely byappropriate medical personnelif sedation or anesthesia isrequired to obtain images. Ifabnormalities suggestive ofcraniocervical compromise aredetected in the medical history,neurologic examination, orsleep study, then neuroimagingis indicated. Neuroimagingshould not be used in isolationto determine when or whethersurgery is indicated.

4. Consider the pros and cons of theneuroimaging options:

a. Computed tomography withthin cuts and bone windows:

i. Can compare foramenmagnum size withpublished achondroplasianorms.46,47

ii. May be possible withoutsedation.

iii. Does not provide adequateimages of brainstem andupper cervical cord todetermine if there is neuralcompromise, signalingchange.

b. MRI:

i. Provides direct assessmentof the brainstem and uppercervical spinal cord, but nostandards for estimation offoraminal size by MRI arecurrently available.

ii. May require generalanesthesia if fast MRIprotocol is not used oravailable. Generalanesthesia should only be

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performed in a clinicalsetting in which a pediatricanesthesiologist, nurseanesthetist, or other airwayspecialist is present tomanage the procedure.Often, a newborn infant canbe wrapped and scannedwhile asleep withoutsedation or anesthesia,particularly when a fastermagnetic resonance scanneris available.

iii. Evidence that flexion orextension of the cervicalspine during MRI mayreveal dynamic cordcompression and alterationof cerebrospinal fluid (CSF)flow in achondroplasia,which is a better indicatorof the need for surgicalintervention.48,49

5. Refer in a timely manner toexperienced neurosurgicalspecialist if any of the followingare detected during theaforementioned craniocervicaljunction assessment:

a. Abnormal neurologicexamination marked byhypotonia or “floppiness,”weakness, sustained lowerextremity clonus, asymmetricreflexes, or choking or gaggingwith eating.

b. Poor weight gain onachondroplasia-specific growthcharts, especially if caloricintake and/or infant feeding issufficient.

c. Sleep study showing hypoxemicepisodes with oxygensaturation ,85% and/orcentral apnea beyond thatexpected in an average-stature,healthy newborn infant.50

d. Imaging showing markedsmaller foramen magnum size,substantial deformation of theupper cervical spinal cord, orlack of CSF around thespinal cord.

6. Establish care with a pediatricorthopedist to monitor the spine.

7. Confirm newborn screeninghearing result and follow-up failedscreening results with formalaudiology assessment.

Anticipatory Guidance

1. Discuss the following possiblesevere medical complications andmethods of prevention:

a. Unexpected infant deathoccurs in 2% to 5% of allinfants withachondroplasia50,51 ifaggressive, early assessmentsare not pursued to detectcentral apnea resulting fromcompression of the brainstemand arteries at the level of theforamen magnum.

b. The universally small foramenmagnum may result in a highcervical myelopathy,52,53 alsodetectable by theaforementioned earlyassessments.

c. Macrocephaly with excessiveextra-axial fluid andasymptomaticventriculomegaly is a normalfeature of achondroplasia54

but may be complicated byhydrocephalus.

i. Should head circumferenceincrease unexpectedly onan achondroplasia-specificcurve, the fontanelle bulgeor become hard topalpation, or lethargy,irritability, poor weightgain, or markeddevelopmental delay occur,the imaging and potentialreferral to a neurosurgicalspecialist is indicated.

ii. Benign extra-axial fluid andasymptomaticventriculomegalyvisualized by MRI shouldnot be misinterpreted asindicative of need for shuntplacement.

d. Restrictive pulmonary diseaseoccurs in less than 5% ofchildren with achondroplasiawho are younger than3 years.55 Living at highelevation may exacerbatepulmonary complications as inaverage-stature individuals.Obstructive pulmonarydisease is muchmore common andwarrants systematicassessment.15,56,57

2. Be aware that most infants withachondroplasia developthoracolumbar kyphosis. Moresevere kyphosis is associatedwith unsupported sitting beforethere is adequate trunk musclestrength and tone.58,59 Borkhuuet al60 observed developmentaldelays in motor skillacquisition (compared with otherchildren with achondroplasia) tobe highly associated withprogression of thoracolumbarkyphosis.61

a. Back support should beprovided during bottle and/orbreastfeeding.

b. Unsupported sitting anddevices that cause curvedsitting or “C sitting,” such as“umbrella-style” strollers andsoft canvas seats, should beavoided during the first yearof life.

c. Care with a pediatricorthopedist should beestablished to monitorthe spine.

3. Be aware that the commoncomplication of spinal stenosisrarely occurs in childhood butmanifests in older individualswith numbness, weakness, andaltered deep tendon reflexes.52

Severe thoracolumbar kyphosiscan greatly exacerbate spinalstenosis; thus, therecommendation is to avoidunsupported sitting before there

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FIGURE 3Fifth, 50th, and 95th percentiles for weight for boys (top) and girls (bottom) 0 to 36 months of age with achondroplasia (solid lines) compared with thoseof the general population (dotted lines), based on 1853 observations from 155 boys and 128 girls with achondroplasia. Adapted from Hoover-Fong JE,Schulze KJ, McGready J, Barnes H, Scott CI. Age-appropriate body mass index in children with achondroplasia: interpretation in relation to indexes ofheight. Am J Clin Nutr. 2008;88(2):364–371. Curves for the US population are from Kuczmarski RJ, Ogden CL, Guo SS, et al. 2000 CDC Growth Charts for theUnited States: Methods and Development. Hyattsville, MD: National Center for Health Statistics; 2002. Illustration is from Growth References. Third edition.2011. Permission for use was granted by the Greenwood Genetic Center.

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FIGURE 4Fifth, 50th, and 95th percentiles for weight for boys (top) and girls (bottom) 2 to 16 years of age with achondroplasia (solid lines) compared with those ofthe general population (dotted lines), based on 1853 observations from 155 boys and 128 girls with achondroplasia. Adapted from Hoover-Fong JE,Schulze KJ, McGready J, Barnes H, Scott CI. Age-appropriate body mass index in children with achondroplasia: interpretation in relation to indexes ofheight. Am J Clin Nutr. 2008;88(2):364–371. Curves for the US population are from Kuczmarski RJ, Ogden CL, Guo SS, et al. 2000 CDC Growth Charts for theUnited States: Methods and Development. Hyattsville, MD: National Center for Health Statistics; 2002. Illustration is from Growth References. Third edition.2011. Permission for use was granted by the Greenwood Genetic Center.

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FIGURE 5Head circumference curves (mean6 2 SD) for children with achondroplasia (solid lines) compared with those for the general population (dashed lines).Data are derived from 114 boys and 145 girls. Graphs are adapted from Horton WA, Rotter JI, Rimoin DL, Scott CI, Hall JG. Standard growth curves forachondroplasia. J Pediatr. 1978;93(3):435–438. General population curves are from Rollins JD, Collins JS, Holden KR. United States head circumferencegrowth reference charts: birth to 21 years. J Pediatr. 2010;156(6):907–913.e2. Illustration is from Growth References. Third edition. 2011. Permission foruse was granted by the Greenwood Genetic Center.

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is adequate trunk musclestrength and tone.

4. Advise parents to use an infantseat or infant carrier that hasa firm back (not excessivepadding) to support the neck andto use a rear-facing car safetyseat for as long as possible.

a. Car seat laws vary by state(and country) as to the age,weight, and/or height ofa child required to converttheir seat to forward-facing.Inquire with local experts (eg,police, hospital, or fire stationwhere car seat installationclinics are offered) or onlinemotor vehicle administration.

b. Infants should not sleepunattended in car seats; this isespecially important in thosewith achondroplasia becausedecreased axial tone andstrength in combination withthe large head creates greatrisk of craniocervical andairway compromise.

5. Avoid use of products likemechanical swings and carryingslings to limit uncontrolled headmovement around the smallforamen magnum. There is a riskof death if the cervicomedullaryjunction is compromised, even ininfants in which there were nosigns of abnormal neurologicstatus. Always support the headand neck with the caregiver’shand, minimizing flexion andextension (also known as headbobbling).

6. Advise parents that normalintelligence is expected.

7. Advise parents that overall,people with achondroplasia havefairly normal life expectancy.However, the following should benoted:

a. Wynn et al61 demonstrated10-year earlier mortality.62

b. Longitudinal studies arerequired to determine the

cause for this, but seriousproblems may occur duringinfancy (eg, cervicomedullarycompression, central sleepapnea), as noted.

8. Inform parents that growthhormone and vitaminsupplements are not effective insignificantly increasing stature.Growth hormone may causea temporary increase in growthvelocity, but little to nosignificant increase in end heighthas been shown.8–11

9. Discuss the availability ofextended limb lengtheningusing a variety of surgicaltechniques, which canresult in an increase inultimate height.

a. This is a long process withhigh cost and associatedphysical pain and can havepostoperative adverse effects.

b. If a family undertakes thisprocedure, it is critical that theaffected child and parentshave discussed this at greatlength and that they are inagreement that proceedingwith this surgery is theappropriate decision for them.

c. If pursued, it should becompleted at a well-established surgical centerwith experience and thecapability to manage thesepatients long-term forcomplications.

10. Inform parents that the finalexpected adult height for peoplewith achondroplasia isapproximately 120 to 135 cm(4–4.5 ft).

11. If an individual withachondroplasia requiresanesthesia and surgery, considerthe following63:

a. Care should be taken inmanipulation of the neckbecause uncontrolled neckmovement (as may occur with

intubation) could lead tounintentional spinal cordcompression secondary toconstriction of the foramenmagnum.

b. Medication should be dosedfor patient size, not age.

c. Venous access may be moredifficult because of incompleteelbow extension.

d. In general, spinal or epiduralanesthesia should be avoidedunless neuroimaging revealsadequate space inside thespinal canal and there are nosigns of neurologiccompromise.

HEALTH SUPERVISION FROM 1 MONTHTO 1 YEAR OF AGE: INFANCY

Diagnosis, Genetic Counseling

1. For infants not diagnosed in thenewborn period, confirm diagnosisby radiographs andphysical examination andoffer molecular confirmation, ifdesired.

2. Inquire about personal supportavailable to the family.

3. Inquire about contact withsupport groups.

4. Observe the emotional status ofparents and intrafamilyrelationships.

5. Discuss the importance of normalsocializing experiences with otherchildren.

6. Ask the parents whether they haveeducated their family membersabout achondroplasia and offerresources to the Little People ofAmerica or local geneticcounselors; discuss siblingadjustment.

7. Review genetics of achondroplasiaas outlined in the Birth to 1 Monthsection, as needed.

Medical Evaluation

1. Assess growth (length, weight,head circumference) and

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development only in comparisonwith children with achondroplasia(Figs 1–5).

2. Perform physical examination,including neurologic examination.

3. Check motor development anddiscuss development; note on themilestone charts forachondroplasia.20,22 Expect motordelay as compared with average-stature, age-matched children butnot social or cognitive delay.

4. For infants not diagnosed in thenewborn period, arrange forpolysomnography andneuroimaging at the time ofdiagnosis.

5. Refer the infant to a pediatricneurologist or pediatricneurosurgeon if any of thefollowing are present:

a. Head circumferencedisproportionately large forlength and weight onachondroplasia-specific curvesor head circumference crossingpercentiles.

b. Fontanelle bulging or becominghard to palpation.

c. Abnormal neurologicexamination marked byhypotonia or “floppiness,”lethargy, irritability, weakness,sustained lower extremityclonus, asymmetric reflexes,choking or gagging with eating,or early hand preference, whichmay be attributable tohydrocephalus orcraniocervical junctioncompromise.

d. Poor weight gain onachondroplasia-specific growthcharts, especially if caloricintake is sufficient.

e. Polysomnography showinghypoxemic episodes withoxygen saturation lower than85% and/or central apneabeyond that expected in anaverage-stature, healthyinfant.50

f. Imaging showing markedsmaller foramen magnum size,substantial deformation of theupper cervical spinal cord, orlack of CSF around spinal cord.

6. Check for serous otitis media.Formal behavioral audiometricassessment should be completedby 9 to 12 months of age andmanaged as part of routine healthcare for patients withachondroplasia, ideally on anannual basis.62,64 Language delaymay be present secondary toconductive hearing loss.

7. Continue to monitor forprogression of kyphosis at thethoracolumbar junction.

a. Parents and therapists (if used)should be instructed to provideback support during the firstyear of life.

b. Avoid unsupported sitting anddevices that cause curvedsitting or “C sitting,” such as“umbrella-style” strollers andsoft canvas seats, during thefirst year of life.

c. Position the infant for feedingwith a straight back and headand neck in alignment,supported by firm pillows;a feeder seat may be a goodoption.

d. Mild, mobile (nonfixed)thoracolumbar kyphosis willoften improve or resolve whenthe child begins to walk.

e. If severe kyphosis appears tobe developing, seek pediatricorthopedic assessment todetermine if bracing is needed.Rarely, surgical interventionmay be necessary.59,60

Anticipatory Guidance

1. Discuss early-intervention servicesif needed. This is not a uniformrecommendation simply becauseof the diagnosis of achondroplasia.

2. Review the increased risk ofserous otitis media because of

short eustachian tubes. Indicatethat an ear examination isappropriate with any persistent orsevere upper respiratorytract infection or when parentssuspect that ear pain may bepresent.

3. Recommend annual audiologyassessment as part of routinehealth care for patients withachondroplasia.62,64

4. There is a risk of jugular bulbdehiscence (absence of thetemporal bone “roof” over thejugular bulb) in patients withachondroplasia. Thismalformation predisposes toaccidental puncture of the jugularbulb during tympanostomy tubeplacement.65

5. Avoid infant carriers and seatedpositions that “curl up” the infantor young child and avoidprolonged unsupported sitting.

6. Advise parents to use an infantseat or infant carrier that hasa firm back (reduced padding) tosupport the neck and to use a rear-facing car safety seat for as long aspossible.

a. Car seat laws vary by state (andcountry), so inquiry with localexperts (eg, police, hospital, orfire station where car seatinstallation clinics are offered)or online motor vehicleadministration isrecommended.

b. Infants should not sleepunattended in car seats; this isespecially important in thosewith achondroplasia becausedecreased axial tone andstrength in combination withthe large head creates great riskof craniocervical and airwaycompromise.

7. Be aware that external rotation ofthe hips is commonly present andusually disappears spontaneouslywhen the child begins to bearweight. This finding does notrequire bracing for the infant.

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8. Discuss the option offiling for SupplementalSecurity Income benefits asappropriate.

HEALTH SUPERVISION FROM 1 YEAR TO5 YEARS: EARLY CHILDHOOD

Diagnosis, Genetic Counseling

1. Review genetics of achondroplasiaas outlined in the Birth to 1 Monthsection, as needed.

2. Inquire about contact withsupport groups.

Medical Evaluation

1. Assess growth (length or height,weight, head circumference) anddevelopment in comparison onlywith children withachondroplasia (Figs 1–5).

2. Assess BMI on achondroplasia-specific charts66 in accordancewith AAP recommendations tomeasure BMI.

3. Perform physical examination,including neurologicexamination.

4. Check motor development anddiscuss development; note on themilestone charts forachondroplasia.20,22 Expectmotor delay as compared withaverage-stature, age-matchedchildren but not social orcognitive delay.

5. Continue to monitor forthoracolumbar kyphosis. Anykyphosis present should resolveas the child begins to bearweight. Lumbar lordosis usuallydevelops but rarely requiresspecific intervention. Weightbearing and walking may occurlate; however, they areexpected by 2 to 2.5 years ofage. When weight bearingbegins, the external rotation ofthe hips should self-correct toa normal orientation within 6months.

6. Anticipate some bowing of thelegs. Many children will also have

instability of the soft tissuessurrounding the knee andinternal tibial torsion. Ifpositional deformity andinstability leads to difficultywalking, a thrust at the knee(uncontrolled lateral ormedial movement withweight bearing), or chronicpain, consult a pediatricorthopedist.

7. Check the child’s hips for hipflexion contractures. Refer tophysical therapy or pediatricorthopedics for exerciserecommendation to decreaselumbar lordosis and hip flexioncontractures if indicated.Stretching of the hip is performedgently so as not to causesubluxation.

8. Ensure that the patient has anaudiology assessment every yearin conjunction withestablishment of care with anotolaryngologist.62,64

9. Ensure that the patient hasa speech evaluation at no laterthan 2 years of age. If speech isdelayed, conductivehearing loss attributable tochronic serous otitis mediashould be excluded.

10. Because most children withachondroplasia snore, monitorclosely for signs of obstructivesleep apnea (increasedretraction, glottal stops, choking,intermittent breathing, apnea,deep compensatory sighs,secondary enuresis, recurrentnighttime awakening oremesis) is recommended. Ifobstructive sleep apnea issuspected, then pulmonaryconsultation andpolysomnography are indicated.

11. Be aware that gastroesophagealreflux disease may be morecommon in children withachondroplasia and may be morecommon in those withneurorespiratory

complications.67 In addition tousual treatments forgastroesophageal reflux disease,consider referral to a pediatricgastroenterologist orpulmonologist.

12. Do not misinterpret greater-than-average sweating as indicative ofserious medical problems; it isnormal in many children withachondroplasia, particularlywhile sleeping. But if there issweating with eating or thesweating increases dramaticallywhile sleeping and airwayobstruction is observed, considerfurther evaluation witha sleep study.

13. In rare instances in whichdiagnosis of achondroplasia isdelayed beyond 1 year of age,arrange for polysomnography forall individuals and neuroimagingon the basis of clinical signs andsymptoms concerning forcraniocervical compression, asdiscussed previously.

Anticipatory Guidance

1. Consider adapting the home sothat the child can becomeindependent (eg, lower the lightswitches, use lever door handlesand lever sink faucets, make thetoilet accessible, and supply stepstools). Determine if anoccupational therapyconsultation is needed to helpadapt the home.

2. Discuss adapting age-appropriateclothing with snapless, easy-opening fasteners and tuckableloops because children withachondroplasia have smallerfingers and shorter arms.Determine if an occupationaltherapy consultation is needed.

3. Discuss adaptation of toys, suchas tricycles, to accommodateshort limbs.

4. Discuss adaptation of toilets toallow comfortable, independentuse. An extended wand for

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wiping is rarely needed in thisage group, provided surgicalspinal fusion has not beenperformed. Discusstoileting at school and specialpreparations needed by theschool because of the child’sshort stature.

5. Discuss the use of a stool duringsitting so that the child’s feet arenot hanging. Feet need supportwhile the child is sitting at a desk,in a chair, or on the toilet. Acushion behind the child’s backmay be required for good postureand to prevent chronic back pain.

6. Counsel parents for optimalprotection to use a convertiblerear-facing car safety seat to thehighest weight and heightallowed by the manufacturer ofthe seat.68 A rear-facing seatprovides the best supportprotection and positioning anglefor a child with macrocephalyand skeletal dysplasia.

7. Review weight control and eatinghabits to avoid obesity, whichoften becomes a problem in midto late childhood and throughadulthood.

8. Discuss orthodontic bracing andthe potential need for palatalexpansion in the future.

9. Encourage all physical activitiesin which the child can participatesafely. All children should avoidtrampolines69 and high-impact,body-contact, and collisionsports.70

10. Discuss how to talk with the childand friends or family membersabout short stature.

11. Encourage preschool attendanceso that the child can learn tosocialize in an age-appropriateway, and work with parents toprepare the teacher and the otherchildren so that the child istreated in an age-appropriatemanner (ie, not dictated by thechild’s height).

HEALTH SUPERVISION FROM 5 TO13 YEARS: LATE CHILDHOOD

Diagnosis, Genetic Counseling

1. Review genetics of achondroplasiaas outlined in the Birth to 1 Monthsection, as needed.

2. Inquire about contact withsupport groups. They areespecially useful at this age.

Medical Evaluation

1. Assess growth (height, weight,head circumference) anddevelopment in comparison onlywith children with achondroplasia(Figs 1–5).

2. Review weight control.44,66

Encouraging and maintainingphysical activity with dietary intake isimportant.

3. Complete a general andneurologically oriented physicalexamination.

4. Check deep tendon reflexes yearlyfor asymmetry or increased reflexesthat suggest spinal stenosis.

5. Continue to assess history forpossible obstructive sleep apnea(increased retraction, glottal stops,choking, intermittent breathing,apnea, deep compensatory sighs,secondary enuresis, recurrentnighttime awakening or emesis). Ifobstructive sleep apnea issuspected, then pulmonaryconsultation andpolysomnography are indicated.

6. Ensure that formal hearingassessment is conducted as part ofannual health maintenance forpatients with achondroplasia,62,64

with ear, nose, and throat follow-up should problems be identified.

7. Assess for pain and its effects onactivities of daily living anddesired physical activity.26

Anticipatory Guidance

1. Determine school readiness.

2. Discuss preparation of the schooland teacher for a child with shortstature. Suggest adaptive aids for

the school to cope with heavydoors, high doorknobs, reachingfor the blackboard, foot support,and a regular-sized desk. Also, besure that the child can use therestroom independently.

3. Prepare the child for thequestions and curiosity of others.

4. Assure the parents that childrenwith achondroplasia usually areincluded in the regular educationprogram.

5. Counsel parents to use a childsafety seat with a full harness tothe highest weight allowed by themanufacturer of the seat andthen to transition to the belt-positioning booster seat foroptimal seatbelt positioning.

6. Review socialization and fosterindependence.

7. Maintain orthopedic surveillanceevery 1 to 2 years or sooner, ifproblems occur.

8. Emphasize supported sitting inschool desks and while doinghomework to avoid kyphosis.

9. Develop an activity program withacceptable activities, such asswimming and biking. The childshould avoid competitivegymnastics and collision sportsbecause of the potential forneurologic complicationssecondary to cervical spinalstenosis.

10. Review orthodontic and speechstatus.

HEALTH SUPERVISION FROM 13 TO21 YEARS OR OLDER: ADOLESCENCE TOEARLY ADULTHOOD

Diagnosis, Genetic Counseling

1. Discuss the diagnosis with theadolescent to be sure that he orshe has the vocabulary and theunderstanding of the geneticnature of achondroplasia.

2. Discuss contraception. People withachondroplasia usually are fertile.The importance and use of

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contraception should be discussedwith both male and femaleadolescents with achondroplasia,just as it should be for average-stature adolescents. Tailored to thematurity and sexual activity of theadolescent or young adult, reviewrecurrence risk counseling with thepatient, as outlined in the PrenatalVisit section previously. The parentsof adolescents or young adults mayhave heard this information for theirrecurrence risk counseling; now theadolescent needs this informationfor his or her reproductive decision-making. Ideally, discussions aboutprenatal testing, pregnancy, anddelivery are conducted beforeconception occurs.38

3. Continue to encourageparticipation in social activities andsupport groups. It is particularlyuseful during this age period.

4. Per the published AAP guidelinesfor adolescent health, proceedwith discussions regardingsmoking, drug use, alcohol use,sexual activity, gender identity,exposure to weapons, food andshelter security, and a focus onbullying and psychological health.

Medical Evaluation

1. Continue to record growthparameters.

2. Review weight control and diet.Encouraging and maintainingphysical activity with dietaryintake is necessary.

3. Complete a general andneurologically oriented physicalexamination. Monitor for any signsor symptoms of nervecompression and check deeptendon reflexes, tone, and sensoryfindings.

4. Continue to assess for possibleobstructive sleep apnea and obtainpolysomnography on the basis ofsymptoms.

5. Formal hearing assessment isrecommended as part of routine

health care for patients withachondroplasia, ideally on anannual basis.

6. Assess for pain and its effects onactivities of daily living anddesired physical activity.

Anticipatory Guidance

1. Check on social adaptation. Fosterindependence.

2. Review orthodontic status.

3. Continue weight counseling.

4. Encourage the family and affectedpatient to set career and life goalshigh and appropriate, as for othermembers of the family.

5. Discuss college, vocationalplanning and training, and otherplans after high school.

6. Discuss driving. A driver’s licenseis obtainable. Drivers usuallyrequire a vehicle that is adaptedwith pedal extenders; extendersthat can be easily mounted andremoved as needed are available.Consultation with a local driverrehabilitation specialist or theAssociation for DriverRehabilitation Specialists (http://www.aded.net/; phone 866-672-9466) may be helpful if vehiclemodifications are needed.Individuals who want to have anair bag on-off switch must read aninformational brochure andsubmit an official request to theNational Highway Traffic SafetyAdministration (1-888-327-4236;www.nhtsa.gov).

7. Assist in transition to adulthealth care.

HEALTH SUPERVISION FOR ADULTSWITH ACHONDROPLASIA

Health supervision for adults withachondroplasia, which includesgenetic counseling, medical concernsand surveillance, and anticipatoryguidance, is multifaceted. Healthsupervision requires specificmanagement recommendations basedon the scope of the disease and

symptomatology of the patient.Several of the key features thatshould be addressed in adulthood areincluded in the Prenatal Visit sectionfor short-stature adults and noted inTable 1.

LEAD AUTHORS

Julie Hoover-Fong, MD, PhD, FACMGCharles I. Scott, MD, FAAPMarilyn C. Jones, MD, FAAP

COUNCIL ON GENETICS EXECUTIVECOMMITTEE, 2017–2018

Emily Chen, MD, PhD, FAAP, Co-ChairpersonTracy L. Trotter, MD, FAAP, Co-ChairpersonSusan A. Berry, MD, FAAPLeah W. Burke, MD, FAAPTimothy A. Geleske, MD, FAAPRizwan Hamid, MD, PhD, FAAPRobert J. Hopkin, MD, FAAPWendy J. Introne, MD, FAAPMichael J. Lyons, MD, FAAPAngela Scheuerle, MD, FAAPJoan M. Stoler, MD, FAAP

FORMER EXECUTIVE COMMITTEE MEMBERS

Robert A. Saul, MD, FAAP, ChairpersonDebra L. Freedenberg, MD, FAAPMarilyn C. Jones, MD, FAAPBeth Anne Tarini, MD, MS, FAAP

LIAISONS

Katrina M. Dipple, MD, PhD – AmericanCollege of Medical GeneticsMelissa A. Parisi, MD, PhD – Eunice KennedyShriver National Institute of Child Health andHuman DevelopmentBritton D. Rink, MD – American College ofObstetricians and GynecologistsJoan A. Scott, MS, CGC – Health Resources andServices Administration, Maternal and ChildHealth BureauStuart K. Shapira, MD, PhD – Centers forDisease Control and Prevention

STAFF

Paul Spire

ABBREVIATIONS

AAP: American Academy ofPediatrics

CSF: cerebrospinal fluidFGFR3: fibroblast growth factor

receptor type 3

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FINANCIAL DISCLOSURE: Dr Hoover-Fong received research support from Alexion and BioMarin, participated on Alexion’s advisory board (not related to

achondroplasia), and has a consultancy and educational relationship with BioMarin (related to achondroplasia); and Drs Scott and Jones have indicated they have

no financial relationships relevant to this article to disclose.

FUNDING: No external funding.

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

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GENETICSJulie Hoover-Fong, Charles I. Scott, Marilyn C. Jones and COMMITTEE ON

Health Supervision for People With Achondroplasia

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