Cytogenetic study of Malaysian neonates with congenital abnormalities in Maternity Hospital Kuala Lumpur.

During the period 1 January 1990-31 December 1990, 68 neonates with congenital abnormalities were successfully analysed for chromosome abnormalities in order to determine the contribution of chromosome aberrations to the aetiology of congenital abnormalities. The neonates were karyotyped employing the G-banding technique. Twenty-nine babies showed abnormal chromosome karyotypes. Twenty-six were observed to have classic trisomy syndromes; ie. trisomy 21 (32.3%), trisomy 18 (3.0%), and trisomy 13 (3.0%). The mean maternal age of the mothers with babies having normal karyotype was lower than the mean maternal age of the mothers having babies with abnormal karyotypes. From this study the incidence of congenital abnormalities due to chromosomal abnormalities is found to be 1:838 livebirths. Frequency of newborns having abnormal chromosomes is 0.14% for Malays, 0.12% for Chinese and 0.06% for Indians.