Consanguinity and congenital heart disease in the rural Arab population in northern Israel.

The incidence of congenital heart disease (CHD) was examined in relation to the consanguinity of the parents. The study was performed in five Arab villages in the Western Galilee, Israel, where consanguineous matings are known to be very high. All children up to the age of 7 years were included in this study; there were 1,546 children, 32% were the offspring of consanguineous marriages including first- and second-degree cousins. A higher percentage of isolated CHD was found in the offspring of consanguineous marriages: 2.81% out of 498 children compared to 1.24% in 1,048 offspring of unrelated parents. Among 373 children whose parents were first cousins the percentage of CHD rose to 3.22. The differences in CHD frequencies were found to be statistically significant. CHD is believed to have a multifactorial background. This study shows that the genetic influence is an important factor in the etiology of such malformations.