Double aneuploidy (47,XX,21+-45,X) arising through simultaneous double non-disjunction.
D000015:Abnormalities, Multiple / Q000235:genetics; D000782:Aneuploidy; D001345:Autoradiography; D001706:Biopsy; D002904:Chromosomes, Human, 21-22 and Y; D004314:Down Syndrome / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007231:Infant, Newborn; D007962:Leukocytes / Q000166:cytology; D009030:Mosaicism; D009061:Mouth Mucosa / Q000166:cytology; D012728:Sex Chromatin; D012730:Sex Chromosomes; D012867:Skin / Q000166:cytology