title: Genetic heterogeneity of non-specific mental retardation.
abstract: OBJECTIVE
  To explore genetic patterns of non-specific mental retardation (NSMR).
  
  
  METHODS
  Using segregation analysis, Finney method and Falconer method, the authors studied 157 pedigrees with NSMR selected in a population survey in Shandong province.
  
  
  RESULTS
  Ux U multiplex families may accept the autosomal recessive inheritance, Ux U total families is the autosomal recessive inheritance while it may be the multifactorial inheritance with major-gene effect, the frequency of sporadic cases is approximately 46%; Ux A mating families may keep the incomplete penetrance in autosomal dominant inheritance.
  
  
  CONCLUSIONS
  The genetic pattern of NSMR has the genetic heterogeneity.
authors.affiliation: Department of Medical Genetics, Shandong Medical University, Jinan, Shandong, 250012 P. R. China. chenjie81@163.net
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
authors.forename: M
authors.initials: M
authors.lastname: Zhao
mesh_terms: D005260:Female; D014644:Genetic Variation; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male