FREE NEJM E-TOC    HOME   |   SUBSCRIBE   |   CURRENT ISSUE   |   PAST ISSUES   |   COLLECTIONS   |   Search Term  Advanced Search

Sign in | Get NEJM's E-Mail Table of Contents — Free | Subscribe

Previous Volume 303:662-664 September 18, 1980 Number 12 Next

	Add to Personal Archive Add to Citation Manager Notify a Friend E-mail When Cited PubMed Citation

Abstract

Males affected by one form of X-linked retardation possess the X-chromosomal marker fra(X)(q27) and are physically normal except for macro-orchidism. To relate possession of the marker X to phenotypic expression in female heterozygotes, we investigated 128 mildly retarded (IQ, 55 to 75) school-girls in Sydney, New South Wales, Australia. Seventy-two girls had no physical abnormalities and of these, five (7 per cent) carried the marker X. Investigation of relatives revealed retarded males in four of the five families. Pedigree and chromosomal analysis identified a further 18 heterozygotes; six were regarded as intellectually or educationally retarded. We conclude that expression of the X-linked mutation in female carriers contributes to mild mental retardation of girls, that those who are physically normal should be screened for the marker X, and that their relatives should be investigated in order to identify additional females with a high risk of conceiving affected males.

This article has been cited by other articles:

• Shevell, M., Ashwal, S., Donley, D., Flint, J., Gingold, M., Hirtz, D., Majnemer, A., Noetzel, M., Sheth, R.D. (2003). Practice parameter: Evaluation of the child with global developmental delay: Report of the Quality Standards Subcommittee of the American Academy of Neurology and The Practice Committee of the Child Neurology Society. Neurology 60: 367-380 [Abstract] [Full Text]  
• Freund, L. S., Reiss, A. L., Hagerman, R., Vinogradov, S. (1992). Chromosome Fragility and Psychopathology in Obligate Female Carriers of the Fragile X Chromosome. Arch Gen Psychiatry 49: 54-60 [Abstract]  
• Carpenter, N. J., Leichtman, L. G., Say, B. (1982). Fragile X-Linked Mental Retardation: A Survey of 65 Patients With Mental Retardation of Unknown Origin. Arch Pediatr Adolesc Med 136: 392-398 [Abstract]