Fetal alcohol syndrome associated with trisomy 21.

Five cases of Down syndrome in association with fetal alcohol syndrome (FAS) are described. Four of the babies were full term, one was premature. Phenotypically these babies (3M:2F) had manifestations of both Down syndrome and FAS; growth deficiency was more pronounced than is expected in Down syndrome. All measurements, birth weight, length and head circumference were below -2 SD. All had congenital heart disease. Chromosome analysis confirmed 21 trisomy in every case. Down syndrome and FAS may occur together, at random, in 1 in 525,0000 newborns in United States but 1 in 200,000 in our institution. Estimated incidence of FAS and Down syndrome in our institution was 1 in 6,600, a 30-fold increase over the chance occurrence of these two conditions together. Mean age of mothers at delivery was 29.6 +/- 9.3, statistically similar to the mean ages of mothers who delivered Down syndrome and FAS babies in our two hospitals, but was significantly higher than the mean age of mothers in our general population (p less than 0.001). All study cases had chronic alcoholic mothers as well as maternal grandmothers, suggesting that there is an increased incidence of trisomy 21 in children of second generation of alcoholic mothers.