title: [Severe mental retardation in an urban child population].
abstract: The author studied the prevalence of severe mental retardation in Vilnyus and considered the status of its etiological and clinical differentiation. A total of 224 cases of oligophrenia were identified among children aged 4-13 years which constituted a populational rate of 0.31% in the above age group. A marked predominance of males among the cases with undifferentiated forms was ascertained, which is probably due to the accumulation in this group of X-chromosome-linked mental retardation. Cytogenetic examination of 20 suspected cases revealed the syndrome of a fragile X chromosome in 4 patients.
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D008097:Lithuania; D008297:Male; D012737:Sex Factors; D014505:Urban Population; D014960:X Chromosome
vernacular_title: Umstvennaia otstalost' vyrazhennoĭ stepeni v detskoĭ gorodskoĭ populiatsii.