Inherited heart disease in childrenJune 19, 2022
Dr. Mitesh Shetty
Congenital heart defect (CHD) is a common form of birth defect in children. The incidence of CHD is around 9 per 1000 people. The estimated number of children to be born with a heart defect in India is more than two lakh per year. Out of this one-fifth is likely to have serious defect requiring intervention in the first year of life. These days about 85 to 95 percent of children with CHD survive into adulthood due to better surgical and non-surgical techniques. Therefore, the number of adults with CHD is on the rise. These patients when they enter into the reproductive age group need to understand heritability and passing on of the disease to the next generation.
The risk is greater in the offspring of the affected mother which is around 6.5 percent while if the father is affected the risk is around 2.2 percent. Most heart defects are sporadic so we need to find out whether the heart defect is isolated or isolated with a significant family history or is it syndromic-single-gene disorder, or chromosomal level defect, or due to teratogenicity exposure or maternal illness. A history of alcohol or drug exposure in pregnancy like treatment of anti-convulsion, chronic maternal illness like maternal diabetes, and maternal PKU may increase the risk. If there is a history of maternal infection or prematurity, the risk of heart defect is more. Lifestyle may not have a direct impact but alcohol consumption and other illness may have an impact on heart health.
At the genetic level, it can be a chromosomal abnormality or it can be gene level. In pregnancy, everybody is at risk of having a child with a chromosomal abnormality. The risk increases whenever you have any birth defect. The common thing associated during pregnancy and with the heart defect is Down’s syndrome, Edwards’s syndrome, Patau syndrome, Turner syndrome, Williams syndrome and Deletion 22q11 syndrome which are common chromosomal defects. If it’s a second time CHD or family history it may be at the gene level defect like Noonan syndrome, Holt-Oram syndrome, and Smith-Lemli-Opitz syndrome are common single gene disorders. We need to investigate and identify the cause and supportive management accordingly.
We recommend every pregnant woman to take preconception vitamin that is folic acid before planning for pregnancy as it reduces the chances of heart defect, neural tube defect, and cleft lip palate. Most heart defects can be identified in the antenatal period during pregnancy where we can check heart abnormality from Nuchal Translucency (NT) scan at 12 weeks to anomaly scan with foetal echo at around 19-20 weeks, when the heart development completes and the defects should be investigated by performing prenatal diagnosis for genetic defects.
The author is HOD & Consultant – Medical Genetics, Manipal Hospital