Aortic regurgitation and mitral valve prolapse with Down's syndrome: a case-control study.

This case-control study was designed to determine whether aortic regurgitation (AR) and mitral valve prolapse (MVP) are specifically associated with Down's syndrome, or occur in a comparably retarded population without Down's syndrome. The 92 control subjects resided at the same institution as the 131 cases, and had mental retardation attributable to low birth weight or perinatal asphyxia. Mean (+/- SD) ages of the cases and the control group were 41 +/- 11 years compared with 40 +/- 13 years, respectively. The relative risk of AR among the cases (those with Down's syndrome) was 2.9 (95% confidence interval, 0.65-13.2; P = 0.16) and that of MVP was 3.5 (95% confidence interval, 1.2-10.2; P = 0.02). The results showed that these two valvular abnormalities are specifically associated with Down's syndrome in adults.