No abstract

Data from a chromosome examination of 14,069 consecutive newborn infants is presented. Successful karyotypes were obtained on 13,939 babies using short-term blood culture and conventional staining methods. Of those, 13,645 babies had normal chromosomes; 64 (0.46 %) had a major chromosome abnormality; and 230 (1.65 %) had a marker chromosome; giving a total of 294 (2.11 %) babies with a major chromosome abnormality or distinctive marker chromosomes.Six male babies with sex chromosome abnormalities had a 47,XXY and four a 47,XYY karyotype, and three were mixoploids. Five female babies had a 47,XXX karyotype and two were mixoploids. There were three babies with ambiguous external genitalia, all with normal karyotypes. Fourteen babies had 21-trisomy; there were three 18-trisomics and one 13-trisomic. The mother of one 18-trisomy baby had a balanced (18;21) translocatioii. Twenty-four infants had a balanced chromosome rearrangement. Eleven of these were reciprocal and thirteen were Robertsonian translocations. One baby had an unbalanced derivative chromosome resulting from an 18;ll insertion. Two infants with additional un-

No abstract

No abstract

No abstract