Screening of mentally retarded males for macro-orchidism and the fragile X chromosome.
Four hundred forty-four male residents of a state mental retardation institution were screened for macro-orchidism. Twenty-six white males (8.3%) and two black males (1.5%) had marked macro-orchidism (greater than 34 ml). Seven of 17 whites tested for the fragile X were positive; the one black tested was negative. Thus, a minimum of 7/26 or 27% (whites) are fragile X positive indicating potential population variability, also evident from previous reports. Concurrent testing of institutionalized brother pairs indicated over half of the fragile X-positive males had a strong family history consistent with X-linked mental retardation.
D000328:Adult; D000407:Alabama; D005600:Fragile X Syndrome / Q000453:epidemiology* / Q000235:genetics; D008040:Genetic Linkage; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D012729:Sex Chromosome Aberrations / Q000453:epidemiology*; D013733:Testicular Diseases / Q000235:genetics*