title: A cytogenetic survey of an institution for the mentally retarded. II. C-band chromosome heteromorphisms.
abstract: Heteromorphisms of chromosomes 1, 9, and 16 were studied by C-banding in a population of 403 mentally retarded individuals from diverse ethnic groups. A significant difference in the distribution of heteromorphisms was found among the different racial groups. The Orientals had a larger C-band on chromosome 1 and a smaller C-band on chromosome 9 than the other racial groups while the Caucasians had a larger C-band on chromosome 9. The Oriental group also had a significantly greater proportion of inverted C-bands. No differences were found in the distribution of C-band heteromorphisms among different etiologic categories of mental retardation.
mesh_terms: D000328:Adult; D044466:Asian People; D002871:Chromosome Banding; D002900:Chromosomes, Human, 1-3 / Q000648:ultrastructure; D002902:Chromosomes, Human, 16-18 / Q000648:ultrastructure; D002906:Chromosomes, Human, 6-12 and X / Q000648:ultrastructure; D006254:Hawaii; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D044465:White People