title: [Study of 315 pedigrees with idiopathic mental retardation by segregation analysis].
abstract: 315 pedigrees with idiopathic mental retardation (MR) have been studied by complex segregation analysis. The results show that there is no major gene effect in the mild MR, but in the medium and severe MR there are major gene effect. The pattern of inheritance of the medium MR may be codominant and the penetrance of the dominant gene is 0.91. The mode of inheritance of the severe MR may be recessive and probably without sporadic cases.
authors.affiliation: West China University of Medical Sciences, Chengdu.
authors.forename: Y
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D005787:Gene Frequency; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000145:classification / Q000235:genetics*; D010641:Phenotype