Genetic and Nutritional Causes of Heart Birth Defects

Congenital heart defects are the most common type of birth defect; each year, more than
30,000 babies in the United States are born with this kind of abnormality. Conotruncal heart
defects, considered to be a very serious type of defect, involve a structural abnormality in
the chambers of the heart or blood vessels that lead to and from the heart. Infants born
with conotruncal defects must undergo complex open heart surgery, and there is a high
fatality rate. Folic acid supplementation during pregnancy has been shown to reduce the risk
of conotruncal defects. However, some women who take folic acid during pregnancy still give
birth to infants with conotruncal defects. Specific genes may influence the way individuals
metabolize folic acid, and variations in these genes may make some infants more prone to
developing heart defects. This study will examine the relationship between genes, maternal
nutritional intake, and conotruncal heart defects. The results from this study may help to
determine genetic and nutritional causes of congenital heart defects.

This study will use previously collected data on 550 infants born with conotruncal defects
and 1060 infants born without heart defects. There will be no study visits specifically for
this study. Infant DNA will be analyzed for genes that may play a role in folate metabolic
pathways. Blood previously collected from the mothers during pregnancy will be analyzed for
differences in nutrient intake. Specifically, levels of folic acid, choline, vitamin B12,
and methionine will be examined.

Inclusion Criteria:

- Conotruncal heart defect

Exclusion Criteria:

- If part of control group, must not have heart defect