By Dr. Udaya Kotecha
Congenital heart defects (CHD) affects approximately 1% of newborns worldwide and is major cause of infant mortality and morbidity. Despite continued efforts at prevention, the prevalence of CHD has not decreased over the past 3 decades, highlighting the need to understand the underlying causes. Both genetic and environmental factors have been implicated to be causative with a large number of defects being attributed to an interaction of both. Underlying genetic factors can vary from defects in chromosomes to variations in one’s genes. A genetic factor is more commonly recognized in CHD patients who also have an involvement of other organ systems aka syndromic CHD.
The technological advances in genetic testing are now enabling us to better undertsand the genetic basis of congenital heart disease. Both Next Generation Sequencing, a technology which allows the analysis of multiple genes together as well as Microarray: a test which allows detection of major and minor abnormalities in one’s chromosomes has enabled an increasing number of patients to attain a definitive diagnosis. Providing a definitive diagnosis allows families to understand WHY did the CHD occur and assuages feelings of guilt of ‘not having done enough to prevent it”. A definitive genetic diagnosis allows treating physicians to help counsel families about prognosis and long term outcomes. One of the key benefits of a genetic diagnosis is preventing recurrences.
While the presence of CHD can be diagnosed via ultrasounds and echocardiography during pregnancy, a normal result does not exclude recurrence. Testing for the gene affected in the family, enables an accurate diagnosis and hence helps concerned families make informed decisions like opting for pre-implantation genetic testing. However, it is important to note that in spite of the advances in genomic testing, a large number of cases undergoing genetic testing do not yield a diagnosis thus hinting at hidden genes and mechanisms for the same.
(The author is Head of Division Inherited Genetic Disorders, Neuberg Centre for Genomic Medicine. The article is for informational purposes only. Please consult medical experts and health professionals before starting any therapy, medication and/or remedy. Views expressed are personal and do not reflect the official position or policy of the FinancialExpress.com.)
