GENETIC COUNSELING Dr. Harpreet Singh Thukral Assistant Professor Department of Medicine Govt. Medical College Amritsar
GENETIC COUNSELING
Dr. Harpreet Singh ThukralAssistant Professor
Department of Medicine Govt. Medical College
Amritsar
WHAT IS GENETIC COUNSELING?
Genetic counseling is a communication process between a healthcare
professional trained in genetics and an individual or family affected by or at risk
for an inherited disorder.
GOALS OF GENETIC COUNSELING Promoting awareness of the medical
facts of the genetic condition Explaining the role of heredity in the
expression of the condition and its risk of recurrence
Discussing the options available for dealing with the disorder
Assisting families in choosing the options that are most appropriate for them.
Providing psychosocial support
WHO IS A GENETIC COUNSELOR? Genetic counselors are professionals
trained in the fields of genetics and psychosocial counselling.
They act as advocates for families affected by genetic disorders
They help patients understand the concepts of heredity
Assist them in planning for treatment of affected individuals as well as providing options for future offspring.
WHAT DOES A GENETIC COUNSELOR DO? Review family and medical history. Figure out if the patient or their family members
are at risk for disease. Explain how genetic conditions are passed down
through families. Find and give information about genetic conditions. Provide information about testing options and help
patients decide whether they want testing. Offer guidance to help the patient make informed
choices or life plans. Help patients find referrals to medical specialists,
advocacy , support networks, and other resources.
WHEN SHOULD A PATIENT BE REFERRED FOR GENETIC COUNSELING? Has a pregnancy at age 35 years or older Has a history of infertility or multiple
pregnancy losses Has a family history of an inherited
condition such as cancer, blood disorders, neurogenic conditions etc.
Has a child with a chromosome abnormality
Has a child with short stature, growth delay or overgrowth syndrome
THE GENETIC COUNSELING PROCESS
• Information gathering - Contact with patient (review reason for
appt)- Medical and family history- Records review
• Establishing or verifying a diagnosis - History - Physical exam (not by GC)
THE GENETIC COUNSELING PROCESS (CONTD.)
• Risk assessment - Pedigree - Recurrence risk of known condition - Empiric recurrence risk - Testing
• Information giving - Discussion of natural history of a diagnosis- Decision making
• Psychosocial assessment and counseling - On-going client support
• Follow up - Support resources
AREAS OF GENETIC COUNSELING
Chart TitlePrenatal
29%
Cancer25%
Pediatric 13%
Others (Monogenic Disorders)
33%
National Society of Genetic Counselors, 2012 Professional Status Survey: Executive Summary.
NIPD – NON-INVASIVE PRENATAL DIAGNOSIS
Applications:
Test for chromosomal foetal aneuploidies
Advanced maternal age >35 years of age
High risk on maternal serum screening
High risk of pregnancy loss
NIPD AND GENETIC COUNSELINGCASE STUDY – DOWN SYNDROME More prevalent in women with advanced
maternal age (AMA) i.e. >35 years old High risk on maternal serum screening NIPD vs. Invasive PND Early testing - early decision making Specificity Back up results - reconfirm with CVS/Amnio Inclusivity Explaining the result Management Follow-up and support
ANALYSIS OF CHROMOSOMAL MICRODELETION AND MICRODUPLICATION
50-80% of spontaneous abortion is caused by chromosomal abnormalities such as copy number variation (CNV) and structural aberrants.
Testing services are now available for all known microdeletions/microduplication syndromes and chromosomal numerical aberrances.
APPLICATIONS OF MICRODELETIONS/MICRODUPLICATIONS ANALYSIS
Recurrent/spontaneous miscarriages
Symptomatic individuals
Family members of affected individuals
PND
METABOLIC DISORDERS (INBORN ERRORS OF METABOLISM (IEM)) Majority or metabolic disorders are due
to single genes that code for enzymes that facilitate conversion of various substances (substrates) into others (products).
Most metabolic disorders are inherited in an autosomal recessive pattern.
Part of ‘newborn screening’
CASE STUDY- CARBOHYDRATE METABOLISM DISORDER - GALACTOSEMIA A disorder that affects how
the body processes a simple sugar called galactose to produce energy.
Can result in life threatening complications
Milk products to be replaced with formulas.
Management: immediate dietary intervention if detected on NBS until diagnosis is ascertained
Surveillance: Routine monitoring for accumulation of toxic analytes, routine developmental evaluation
CASE STUDY – HAEMATOLIGICAL- THALASSEMIA Thalassemia is one of the most common
single-gene disorders in the world.
Autosomal Recessive
Part of New Born Screening (NBS)
Genetic testing can be done to identify the gene mutation.
PND/PGD
CANCER GENETIC COUNSELING Cancer – malignant tumors, are developed from
accumulation of unregulated cellular growth
Result of gene mutations or existing gene defects induced by various environmental and/or congenital factors
A series of genetic testing is available for hereditary cancers such as breast, ovarian, colorectal etc.
Personalized cancer therapy (targeted, chemotherapeutic).
CANCER THERAPY AND GENETIC COUNSELING
Family History
Understanding the information
Early detection and testing
CANCER THERAPY AND GENETIC COUNSELING(CONTD.)
Test for polymorphisms
Design a customized therapeutic strategy for patients to reduce side effects of medications.
E.g. CYP2D6 gene and Tamoxifen
GENERAL GENETIC COUNSELING - APPLICATIONS
To know if a condition in the family is genetic
Mendelian Laws of Inheritance
Family of ethnic backgrounds susceptible to specific genetic conditions.
MONOGENIC TESTING
Based on target sequence capture, New Generation Sequencing (NGS) is able to test 145 diseases covering 13 physiological and functional systems.
MONOGENIC DISORDERS AND GENETIC COUNSELING Can test for 145 specific disease related
mutations spanning 13 physiological and functional systems in ONE test.
Understanding the test, implications of results
Explaining the results – report analysis Management and Support Follow-up PND/PGD
FOR MORE INFORMATION
www.geneticcounseling.ae