Background
It is speculated that parents' consanguinity status effects the pattern of congenital heart defects (CHDs). In this study the CHD pattern in children with Down's syndrome (DS) was determined in a Saudi population with a high consanguineous marriage rate and compared with historical cohorts from populations with low prevalence of parental consanguinity.
Material and Method
The prospective study was conducted in an open-access pediatric echocardiography clinic in Riyadh, Saudi Arabia. The subjects were all children with DS proven by clinical and cytogenetic study and referred to the pediatric cardiology service from 2001-2004. Parents' consanguinity was documented and 2D echocardiography and Doppler studies were performed after physical examination, ECG, and chest X-ray for each patient.
Results
CHDs were detected in 54/110 (49%) children. These included ventricular septal defect (VSD: 23/54), patent ductus arteriosus (PDA: 4/54), secundum atrial septal defect (ASD: 14/54), atrioventricular septal defect (AVSD: 8/54), tetralogy of Fallot (2/54), bicuspid aortic valve (1/54), supra-pulmonary stenosis (1/54), and double outlet right ventricle (1/54). Consanguinity was found in 25% of all parents. Aortic stenosis, coarctation of the aorta, transposition of great arteries, and complex heart diseases were not detected.
Conclusions
A slightly higher frequency of CHD was documented in DS children from this population with a high consanguineous marriage rate. The frequencies of specific lesions were similar to those reported locally and internationally; VSD was the most frequently detected in this study. Interesting was the predominance of left-right shunt lesions and the relative rarity of cyanotic and complex CHD in this DS population.

Keywords: Infant, Newborn, Heart Defects, Congenital - complications, Down Syndrome - complications, Parents, Consanguinity, Child, Preschool, Child, Residence Characteristics, Saudi Arabia