title: Double aneuploidy: the frequency of XXY in males with Down's syndrome.
mesh_terms: D000293:Adolescent; D000328:Adult; D000782:Aneuploidy; D002648:Child; D002675:Child, Preschool; D003582:Cytogenetics; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D007621:Karyotyping; D007713:Klinefelter Syndrome / Q000175:diagnosis / Q000235:genetics; D008297:Male; D008423:Maternal Age; D010641:Phenotype; D012728:Sex Chromatin; D012730:Sex Chromosomes