Familial Mongolism; with leukaemia in one member and a normal twinsib in another.
D002648:Child; D002675:Child, Preschool; D004200:Diseases in Twins; D004314:Down Syndrome / Q000150:complications* / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007938:Leukemia / Q000150:complications*; D008297:Male