Two cases of trisomy 21 and one XXY case with atypical clinical features.
Three patients with mental retardation and multiple congenital abnormalities are described. Although their clinical appearance was not suggestive of Down's syndrome, chromosome studies showed a non-disjunctional trisomy 21 in two of the patients. The third case had an unsuspected XXY karyotype.
D000015:Abnormalities, Multiple / Q000175:diagnosis; D000293:Adolescent; D000328:Adult; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis; D007621:Karyotyping; D007713:Klinefelter Syndrome / Q000175:diagnosis*; D008297:Male; D010641:Phenotype