Trisomy 21 in both of dizygotic twins.
D002904:Chromosomes, Human, 21-22 and Y; D003582:Cytogenetics; D004200:Diseases in Twins; D004314:Down Syndrome / Q000235:genetics; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D014314:Trisomy