Genetic diseases and antenatal diagnosis

The different methods of prenatal diagnosis are discussed with special reference to ultrasound scan, amniocentesis for cell culture with processing for chromosome study, biochemical analysis and DNA recombination analysis. Chorionic villi aspiration and fetoscopy are new methods which will enhance considerably the methods for prenatal diagnosis. With regard to chromosome study of amniotic cells, experience with 623 cases is reviewed. 2.7% demonstrated chromosome anomalies and of these Downs anomaly was the commonest. A large proportion of cases requesting for amniocentesis are Caucasians who represent only 2% of the population in Singapore, but 25% of the 440 requests were from Caucasions. The various problems associated with the different methods for prenatal deafness are discussed.