title: The MZ half-sib design: an approach for the examination of the etiology of congenital malformations.
mesh_terms: D002971:Cleft Lip / Q000235:genetics; D002972:Cleft Palate / Q000235:genetics; D003025:Clubfoot / Q000235:genetics; D000013:Congenital Abnormalities / Q000235:genetics*; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008297:Male; D008957:Models, Genetic; D009035:Mothers; D009436:Neural Tube Defects / Q000235:genetics; D010375:Pedigree; D011247:Pregnancy; D011336:Probability; D012306:Risk; D014430:Twins, Monozygotic