title: [Heterochromatic regions and chromosome 21 nondisjunction in man. II. A comparative analysis of the polymorphism of the C bands of chromosomes 1, 9 and 16 in the fathers and mothers of Down's disease children].
abstract: To test a hypothesis on potential role of large heterochromatic regions in chromosome non-disjunction, a comparative analysis of C segment lengths of chromosomes 1, 9, and 16 in fathers and mothers of children with Down's syndrome was carried out. No difference was found between the two groups. The non-disjunction in mothers is known to occur 4 times as frequently as in fathers. This fact does not allow to suppose that the heterochromatic regions may play a certain part in non-disjunction of chromosome 21.
mesh_terms: D000328:Adult; D002648:Child; D002871:Chromosome Banding; D002878:Chromosomes, Human, Pair 1 / Q000648:ultrastructure*; D002885:Chromosomes, Human, Pair 16 / Q000648:ultrastructure*; D002891:Chromosomes, Human, Pair 21 / Q000648:ultrastructure*; D002899:Chromosomes, Human, Pair 9 / Q000648:ultrastructure*; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D006570:Heterochromatin / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D009630:Nondisjunction, Genetic; D011110:Polymorphism, Genetic
chemical_list: D006570:Heterochromatin
vernacular_title: Geterokhromaticheskie raĭony i neraskhozhdenie khromosomy 21 u cheloveka. II. Sravnitel'nyĭ analiz polimorfizma C-segmentov khromosom 1, 9 i 16 u ottsov i matereĭ deteĭ s bolezn'iu Dauna.