Consanguinity and congenital heart disease in Saudi Arabia

First-cousin marriage may be a significant risk factor for specific types o f congenital heart disease in a consanguineous population. Inbreeding studi es suggest an autosomal recessive component in the cause of some congenital heart defects. We studied a large sample of patients with structural conge nital heart defects (CHD) identified through the Congenital Heart Disease R egistry at King Faisal Specialist Hospital in Riyadh, Saudi Arabia. After e xclusions of chromosome abnormalities and non-participation, data were coll ected on 891 consecutive patients who were registered between January and A ugust, 1998. Data on first-cousin consanguinity and type of CHD diagnosis w ere collected. A z test of proportions was used to determine the associatio n between consanguinity and subtypes of CHD. Data indicate that the proport ion of first cousins in the CHD sample is higher than the proportion in the general population, supporting a hypothesis of autosomal recessive gene in volvement in congenital heart disease. When subgroups of CHD were analyzed, first-cousin consanguinity was significantly associated with ventricular s eptal defect (VSD), atrial septal defect (ASD), atrioventricular septal def ect (AVSD), pulmonary stenosis (PS), and pulmonary atresia (PA). There was no relationship between consanguinity and tetralogy of Fallot (TOF), tricus pid atresia (TA), aortic stenosis (AS), co-arctation of the aorta (CoA), an d patent ductus arteriosus (PDA). Thus, in a population with a high degree of inbreeding, consanguinity may exacerbate underlying genetic risk factors , particularly in the offspring of first cousins. There may be a recessive component in the causation of some cardiac defects. (C) 2001 Wiley-Liss, In c.