title: [Heterochromatic regions and the nondisjunction of human chromosome 21. I. Polymorphism of the C-bands of chromosomes 1, 9 and 16 in children with Down's syndrome].
abstract: To test a hypothesis on potential role of large heterochromatic regions in chromosome nondisjunction polymorphism of C segments of chromosomes 1, 9, and 16 in 70 children with Down's syndrome were examined. The C segment lengths of the above chromosomes were shown not to deviate from the normal. To solve the problem, it seems unreasonable to examine children with Down's syndrome.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; 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; D005819:Genetic Markers; D006570:Heterochromatin / Q000648:ultrastructure*; D006801:Humans; D007223:Infant; D008297:Male; D009630:Nondisjunction, Genetic; D011110:Polymorphism, Genetic
chemical_list: D005819:Genetic Markers; D006570:Heterochromatin
vernacular_title: Geterokhromaticheskie raĭony i neraskhozhdenie khromosomy 21 u cheloveka. I. Polimorfizm C-segmentov khromosom 1, 9 i 16 u deteĭ s bolezn'iu Dauna.