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.

PRENATAL

GENETIC COUNSELI

NG

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

PEDIATRIC GENETIC

COUNSELING

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 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

OTHERS – MONOGEN

IC DISORDER

S

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.

MENDELIAN LAW OF INHERITANCE

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