Table 1. Saudi studies that reported association between consanguinity and CHD.

CHD: Congenital heart disease, COA: coarctation of the aorta, TA: truncus arteriosus, TOF: tetralogy of Fallot, PDA: patent ductus arteriosus, AS: aortic stenosis, PS: pulmonary stenosis, PA: pulmonary atresia, AVSD: atrioventricular septal defect, ASD: atrial septal defect, VSD: ventricular septal defect

Study	City	Setting	Data collection year	CHD sample	Conclusion
Becker et al., 1997 [50]	Riyadh	CHD Registry	1998	949	The occurrence of CHD was notably higher in children from first-cousin marriages, at 41.6%, compared to 28.4% in the broader population.
Hamamy 2012 [3]	Nation-wide	Household	2004–2005	11,554	Among the respondents, 56% indicated that CHD was the sole condition linked to first cousin consanguinity.
Shaheen et al., 2015 [53]	Dhahran	Hospital	1996–2000	37 families	In these families, 23 marriages (62%) were consanguineous. The occurrence of dilated cardiomyopathy was notably higher in consanguineous unions, with 26 cases, compared to just 2 cases in non-consanguineous marriages.
Dasouki et al., 2020 [54]	Riyadh	CHD Registry	1998	891	The study revealed that the rate of consanguinity in the sample group was considerably higher at 40.4%, compared to 28.4% in the general population. Certain types of CHD, including PS, PA, AVSD, ASD, and VSD, showed a significant correlation with consanguinity. However, this association was not observed in cases of PDA, COA, AS, TA, or TOF.