Newborn screening is the process of testing newborn babies for treatable genetic endocrinologic, metabolic and hematologic diseases
These metabolic disorders (Inborn errors of metabolism) interfere with the body's use of nutrients to maintain healthy tissues and produce energy.
These inherited disorders can hinder an infant's normal physical and mental development in a variety of ways.
With a simple blood test, these disorders can be diagnosed.
Early diagnosis and proper treatment can make the difference between lifelong impairment and healthy development
1965-Phenylketonuria 1977-Congenital Hypothyroidism 1984-Galactosemia 1987-Biotinidase Deficiency, Maple
Syrup Urine Disease & Hemoglobinopathies
1993-Congenital Adrenal Hyperplasia (CAH)
2003-Medium-Chain Acyl-CoenzymeA Dehydrogenase Deficiency
2004-Citrullinemia, Homocystinuria, Argininosuccinic Aciduria
2005-Expanded Screen Pilot 2006-Screen for more than 48
metabolic disorders 2007-Cystic Fibrosis
Robert Guthrie is the first to identify newborn screening for phenylketonuria in the late 1960s
Congenital hypothyroidism was the second disease widely added in the 1970s.
A blood samples is obtained from child on the second or third day of life .
Sample is collected by pricking the heel of a newborn baby to get enough blood (typically, two to three drops) to fill a few circles on filter paper
The filter paper will be labeled with names of infant, parent, hospital, and primary physician
http://www.youtube.com/watch?v=_MuyGk3GrsU
Use capillary blood from heelFill in all five circlesApply blood to only one side of the filter paperDry Flat at least 3 hoursMail to state laboratory within 24 hours of Collection
Use capillary blood from heelFill in all five circlesApply blood to only one side of the filter paperDry Flat at least 3 hoursMail to state laboratory within 24 hours of Collection
Warm foot for 3 – 5 minutes to increase blood flow
Cleanse site with alcohol Air dry or wipe dry with sterile gauze pad Puncture heel with lancet of no more than
2.0mm in depth Wipe away first drop of blood Apply gentle pressure to allow a large drop of
blood to form Lightly touch filter paper to large drop of blood Allow blood to soak through to completely fill the
circle
Warm foot for 3 – 5 minutes to increase blood flow
Cleanse site with alcohol Air dry or wipe dry with sterile gauze pad Puncture heel with lancet of no more than
2.0mm in depth Wipe away first drop of blood Apply gentle pressure to allow a large drop of
blood to form Lightly touch filter paper to large drop of blood Allow blood to soak through to completely fill the
circle
Front
Back
Causes• Waiting too long to apply blood to the filter paper• Improper use of capillary tubes• Syringe used for blood collection
Causes• Waiting too long to apply blood to the filter paper• Improper use of capillary tubes• Syringe used for blood collection
Causes• something spilled onthe filter paper or it wasset on a wet surfaceprior to or after theapplication of blood
Causes• something spilled onthe filter paper or it wasset on a wet surfaceprior to or after theapplication of blood
Prevention• protect the filter paperfrom coming in contactwith hands or othersubstances before andafter blood collection
Prevention• protect the filter paperfrom coming in contactwith hands or othersubstances before andafter blood collection
Causes• Improper use of capillarytubes and other collectiondevices• Pressing the heel against thefilter paper when obtainingthe screening sample.
Prevention• Avoid touching the filter paperwith heel or collection device
Causes• Improper use of capillarytubes and other collectiondevices• Pressing the heel against thefilter paper when obtainingthe screening sample.
Prevention• Avoid touching the filter paperwith heel or collection device
Causes• Multiple applications of bloodto the same circle• Blood applied to both sides ofthe filter paper• Unevenly distributed blood• Circles of blood touch oroverlapPrevention• Allow one large drop to soakthrough and fill the entirecircle• Apply blood to only one side• Apply blood in circle only
Causes• Multiple applications of bloodto the same circle• Blood applied to both sides ofthe filter paper• Unevenly distributed blood• Circles of blood touch oroverlapPrevention• Allow one large drop to soakthrough and fill the entirecircle• Apply blood to only one side• Apply blood in circle only
The state health department agency run the mandated screening tests on the filter paper samples.
If screens are normal, a paper report is sent to the submitting hospital and parents rarely hear about it
If an abnormality occurs, they inform the physician and hospital.
They arrange an evaluation of the infant by an appropriate specialist physician (depending on the disease).
The specialist will attempt to confirm the diagnosis by repeating the tests by a different method or by performing other corroboratory tests.
Depending on the diagnosis and the risk of delay, the specialist will initiate treatment and provide information to the family.
Screening is available for more than 30 disorders
One screening technique, the tandem mass spectrometry (or MS/MS), can screen for more than 20 inherited metabolic disorders with a single drop of blood
MS/MS measures the ratio of the mass (m) of a chemical to its charge (z)
Extraction with methanol to form butyl ester derivatives of amino acid and acyl carnitine
Injected to mass spectrophotometer
Molecules are ionized and separated based on their M/z ratio
Ions are separated by First MS & Enter collision cell , broken down to fragments
Fragments enter the second ms and separated according to m/z ratio
Ion Exchange Chromatography -amino acids
Gas chromatography – mass spectrometry –
organic acids, acyl glycine
DNA Testing
Enzyme Assays
These second tier tests are performed to prevent the false positive tests