Screening the Utah State Training School (a resident institution for the mentally retarded) for kindreds having at least two institutionalized sibs generated 54 sib groups. Of these, 20-male only sibships had histories compatible with sex-linked mental retardation without physical stigmata (Martin-Bell or Renpenning type). Affected males had no characteristic physical stigmata (an appreciable number did have speech problems and/or seizure disorders) and exhibited IQs ranging from 5 to 74 with a mean of 34.2. Obligate carrier females had a mean IQ score of 91.9 (range, 79 to 106), which is as would be predicted due to random X-inactivation. Carrier females were tested with the MMPI, and showed elevated profiles. The results also indicated that the FAM scale would differentiate between groups of carrier females and normal females and between groups of carrier females and other females who had retarded children. It is suggested that the extension of psychometric methods may be useful in the identification of high risk females. Identification of these females would then allow for accurate genetic counseling, an objective which has not yet been achieved.
College and Department
Plant and Wildlife Sciences
BYU ScholarsArchive Citation
Hanis, Craig L., "Sex-linked mental retardation without physical stigmata (Martin-Bell or Renpenning type) : a genetic and psychometric approach" (1977). Theses and Dissertations. 7776.
Intellectual disability; People with disabilities; Genetics