title: Trisomy 21-trisomy 18 mosaicism in a boy with clinical Down's syndrome.
mesh_terms: D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D009030:Mosaicism; D014314:Trisomy