Genetic analyses ofpyloric stenosis suggesting aspecific maternal effect

Summary.Dataon pyloric stenosis are analysed bymultiple threshold methods that incorporate thesexeffect. Thepolygenic modelofinheritance is rejected; thesingle major locus model canonly accountfor37%ofthe caseshaving agenetic aetiology, requiring an environmental effect toaccountfortheremainder ofthe cases.Amaternal-fetal interaction forgastrin production andsensitivity is postulated toexplain alltheexisting data.Theempirical risk figures givenare considered tobethemostaccuratebasis forgenetic counselling until additional studies provide asoundbiological basis for aquantitative genetic model.