ABSTRACT
The study of Down syndrome in Department of Pediatrics, Siriraj Hospital from 1977-1986 found 183 patients, including 48 neonates and 136 cases admitted with different problems. The objectives of this study were to study families with Down syndrome, correlation of maternal age and birth of Down syndrome, phenotypes and associated congenital anomalies. We found two-thirds of families lived in Bangkok, averaging 3.5 children in each family. Mean maternal age was 32.1 years Sixty-one percent of mothers were younger than 35 years. Mean birthweight was significantly lower than average. There were 105 males and 78 females, given sex ratio of 1.3 to 1. Children with Down syndrome had multiple congenital anomalies. Forty-four percent had congenital heart disease, which one-thirds were ventricular septal defects. Ten percent had gastrointestinal malformation, usually imperforate anus and duodenal atresia. Common hematological abnormalities were myeloproliferative disorder and nonlymphoblastic leukemia. AII patients had developmental retatdation, hypotonia in infancy and mental retardation. Three common causes of illness were pneumonia, acute diarrhea and congestive heart failure.