First-cousin matings and congenital heart disease in Saudi Arabia

Consanguinity may be a risk factor that contributes to congenital heart disease in an inbred population, particularly among first cousins; with high rates of intermarriage between relatives, consanguinity is associated with congenital heart disease particularly among first cousins.

This study examines a group of 1,028 consecutive congenital heart disease (CHD) patients identified through the Congenital Heart Disease Registry at King Faisal Specialist Hospital in Riyadh, Saudi Arabia. Families were interviewed by an Arabic-speaking data collector for information on consanguinity and demographic data. After exclusions for nonavailability, data were collected on 949 cases and the proportions of first-cousin consanguinity in the study sample were compared to national population data. A z test of proportions was utilized to test the hypothesis that there are higher proportions of first-cousin consanguinity in the study sample of congenital heart patients than in the general population.

Data indicate that the proportion of first-cousin matings among CHD patients is significantly higher than that of first-cousin intermarriages reported in the general population (p < 0.001). Regional breakdowns of the data substantiate significant differences (p < 0.001) in the proportions of first-cousin consanguinity in the study sample compared to the general population.

In a population with a high degree of inbreeding, consanguinity may exacerbate underlying genetic risk factors, particularly for offspring of first-cousin matings. This finding has public health implications for genetic counseling and prevention of some cardiac malformations.