Congenital heart disease, maternal age and parental consanguinity in children with Down's syndrome

OBJECTIVE: Analyze the role of parental consanguinity and/or maternal age on the occurrence of congenital cardiac anomalies in infants with Down's syndrome (DS). MATERIAL AND METHODS: A large group of patients with or without congenital heart disease, registered between May 1st, 1999 and June 30th, 2006, at the National Register of Paediatric and Congenital Heart Disease, Lebanese Society of Cardiology. 217 children with DS have been enrolled over this period. Group I: DS with cardiac anomalies (n:119). Group II: DS without cardiac anomalies (n:98). The consanguinity rate was compared to a study made in 2000 by UNICEF in Lebanon, in which the consanguinity rate was 14.9% of 1st degree cousins and 25% of all degrees together. RESULTS: Congenital cardiac anomalies were found in 54.2% of babies with DS. First degree cousins in both groups I and II was 143% (close to the general population), and it was lower in group I compared to group II (11.8% and 17.3% respectively ; p = 0.205) ; this difference was not statistically significant for all degrees together. Maternal age ranged from 20 to 47 years, with a mean of 29.5 +/- 5.3 years. The risk of congenital cardiac anomaly was greater (p < 0.05) when maternal age was equal or below 32 years. As in the international literature, complete atrioventricular canal and ventricular septal defect were the most frequent cardiac anomalies. CONCLUSION: In children with DS, the risk of congenital cardiac anomalies was not associated with the parents consanguinity. Maternal age above 32 years seem to be associated with a lesser occurrence of congenital cardiac anomaly in children with DS.