mental retardation due to down syndrome and other causes in referrals to genetic counseling center in south of iran

introduction: mental retardation, is one of the most common causes for referral to genetic counseling centers, and is one of the greatest challenges in health care services in the world. down syndrome is the most common chromosomal abnormalities in humans. methods: this study performed in medical genetic counseling center of welfare organization in south of iran with high consanguineous marriages with aim of comparison between mental retarded children due to down syndrome and other causes of mental retardation between 2006-2014. participants were 44 children with down syndrome and 71 mental retarded children due to another causes. results: the prevalence of mental retardation was 4.2% and the most common cause of mental retardation was down syndrome (38.2%). there was a significant statistical association between down syndrome and congenital heart defects (p=0.001). conclusion: first and second trimester prenatal screening could help to detect pregnancies with increased risk of fetal chromosomal anomalies.