title: Origin of trisomies in human spontaneous abortions.
abstract: Chromosome heteromorphisms of 34 trisomic abortuses and their parents were compared to determine the origin of the extra chromosome. Fourteen of the trisomies were maternal in origin, ten resulting from a first-meiotic-division error and four from either first- or second-meiotic-division errors. No paternally derived trisomy was identified.
mesh_terms: D000022:Abortion, Spontaneous / Q000235:genetics*; D002901:Chromosomes, Human, 13-15; D002902:Chromosomes, Human, 16-18; D004314:Down Syndrome / Q000235:genetics; D005260:Female; D006801:Humans; D008423:Maternal Age; D008540:Meiosis; D011247:Pregnancy; D014314:Trisomy