A large kindred with X-linked mental retardation, marker X and macroorchidism

Am J Med Genet. 1984 Jan;17(1):145-57. doi: 10.1002/ajmg.1320170109.


Thirty-eight members of a black kindred with mental retardation and the Marker X were studied. Ten of 14 affected males, 6 of 6 affected females, 18 carriers or possible carriers, and 7 normal males were examined. Eight of 9 affected males who could be measured had macroorchidism, but their ears and mandibles were not prominent. No distinct facies were evident, although minor anomalies, such as a slight pectus, were present in some. Clinical diagnosis in the absence of a strongly positive family history may be even more difficult among prepubertal black children than in whites. The risk of retardation among children of carriers was estimated at 20-40%.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Facial Asymmetry / congenital
  • Female
  • Genetic Markers*
  • Heterozygote
  • Humans
  • Intellectual Disability / genetics*
  • Male
  • Middle Aged
  • Pedigree
  • Phenotype
  • Testis / abnormalities*
  • X Chromosome*


  • Genetic Markers