title: Three interesting cases of Down's syndrome.
abstract: The results of the cytogenetic study of three families that have children affected by Down's syndrome are presented. The karyotype of case 1 was 48,XY,+21,22s+,+mar; the marker chromosome had been produced "de novo". Case 2 was: 47,X,t(Xq21q), +t(21qXq); the abnormality had been produced "de novo". Case 3 was carrier of a homogeneous trisomy 21 (47,XY,+21), where the mother was carrier of a balanced translocation 13q14q. CBG, GTG, Ag-NOR, QFQ and FPG banding techniques were used to determine the origin and importance of these anomalies.
mesh_terms: D002648:Child; D002871:Chromosome Banding; D002904:Chromosomes, Human, 21-22 and Y / Q000648:ultrastructure; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D014178:Translocation, Genetic