title: A cytogenetic survey of mentally retarded children in Taiwan: final report on the incidence of chromosome abnormalities.
abstract: A cytogenetic survey of 470 mentally retarded children from three different sources is reported. Thirty-eight patients (8.08%) were found to have recognizable chromosome abnormalities, including 4 cases of sex chromosomes and 34 cases of autosomes. The most prominent category of abnormality was trisomic 21, a total of 26 cases of this type was found in this study. Sex chromosome abnormalities contribute very little to the etiology of mental retardation. From the results of our three groups of patients as well as from those surveyed by others, it is concluded that the more severe the degree of mental retardation, the higher the incidence of chromosome abnormalities.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002869:Chromosome Aberrations / Q000453:epidemiology*; D025063:Chromosome Disorders; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D009006:Monosomy; D012729:Sex Chromosome Aberrations / Q000453:epidemiology; D013624:Taiwan; D014178:Translocation, Genetic; D014314:Trisomy