Abstract
To date over 150 X linked mental retardation (XLMR) conditions have been documented. We describe a five generation South African family with XLMR, comprising 16 affected males and 10 carrier females. The clinical features common to the 16 males included profound mental retardation (100%), mutism despite apparently normal hearing (100%), grand mal epilepsy (87.5%), and limited life expectancy (68.8%). Of the four affected males examined, all had mild craniofacial dysmorphology and three were noted to have bilateral ophthalmoplegia and truncal ataxia. Three of 10 obligate female carriers had mild mental retardation. Cerebellar and brain stem atrophy was shown by cranial imaging and postmortem examination. Linkage analysis shows the gene to be located between markers DXS424 (Xq24) and DXS548 (Xq27.3), with a maximum two point lod score of 3.10. Keywords: X linked mental retardation; epilepsy; cerebellar atrophy; ophthalmoplegia
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- Allen R. C., Zoghbi H. Y., Moseley A. B., Rosenblatt H. M., Belmont J. W. Methylation of HpaII and HhaI sites near the polymorphic CAG repeat in the human androgen-receptor gene correlates with X chromosome inactivation. Am J Hum Genet. 1992 Dec;51(6):1229–1239. [PMC free article] [PubMed] [Google Scholar]
- Arena J. F., Schwartz C., Stevenson R., Lawrence L., Carpenter A., Duara R., Ledbetter D., Huang T., Lehner T., Ott J. Spastic paraplegia with iron deposits in the basal ganglia: a new X-linked mental retardation syndrome. 1992 Apr 15-May 1Am J Med Genet. 43(1-2):479–490. doi: 10.1002/ajmg.1320430172. [DOI] [PubMed] [Google Scholar]
- Gedeon A. K., Kozman H. M., Robinson H., Pilia G., Schlessinger D., Turner G., Mulley J. C. Refinement of the background genetic map of Xq26-q27 and gene localisation for Börjeson-Forssman-Lehmann Syndrome. Am J Med Genet. 1996 Jul 12;64(1):63–68. doi: 10.1002/(SICI)1096-8628(19960712)64:1<63::AID-AJMG9>3.0.CO;2-S. [DOI] [PubMed] [Google Scholar]
- Glass I. A. X linked mental retardation. J Med Genet. 1991 Jun;28(6):361–371. doi: 10.1136/jmg.28.6.361. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gustavson K. H., Annerén G., Malmgren H., Dahl N., Ljunggren C. G., Bäckman H. New X-linked syndrome with severe mental retardation, severely impaired vision, severe hearing defect, epileptic seizures, spasticity, restricted joint mobility, and early death. Am J Med Genet. 1993 Mar 1;45(5):654–658. doi: 10.1002/ajmg.1320450527. [DOI] [PubMed] [Google Scholar]
- Hamel B. C., Smits A. P., Otten B. J., van den Helm B., Ropers H. H., Mariman E. C. Familial X-linked mental retardation and isolated growth hormone deficiency: clinical and molecular findings. Am J Med Genet. 1996 Jul 12;64(1):35–41. doi: 10.1002/(SICI)1096-8628(19960712)64:1<35::AID-AJMG5>3.0.CO;2-Q. [DOI] [PubMed] [Google Scholar]
- Jolly D. J., Okayama H., Berg P., Esty A. C., Filpula D., Bohlen P., Johnson G. G., Shively J. E., Hunkapillar T., Friedmann T. Isolation and characterization of a full-length expressible cDNA for human hypoxanthine phosphoribosyl transferase. Proc Natl Acad Sci U S A. 1983 Jan;80(2):477–481. doi: 10.1073/pnas.80.2.477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kremer H., Hamel B. C., van den Helm B., Arts W. F., de Wijs I. J., Sistermans E. A., Ropers H. H., Mariman E. C. Localization of the gene (or genes) for a syndrome with X-linked mental retardation, ataxia, weakness, hearing impairment, loss of vision and a fatal course in early childhood. Hum Genet. 1996 Nov;98(5):513–517. doi: 10.1007/s004390050250. [DOI] [PubMed] [Google Scholar]
- Lathrop G. M., Lalouel J. M., White R. L. Construction of human linkage maps: likelihood calculations for multilocus linkage analysis. Genet Epidemiol. 1986;3(1):39–52. doi: 10.1002/gepi.1370030105. [DOI] [PubMed] [Google Scholar]
- Lehrke R. Theory of X-linkage of major intellectual traits. Am J Ment Defic. 1972 May;76(6):611–619. [PubMed] [Google Scholar]
- Lubs H. A., Chiurazzi P., Arena J. F., Schwartz C., Tranebjaerg L., Neri G. XLMR genes: update 1996. Am J Med Genet. 1996 Jul 12;64(1):147–157. doi: 10.1002/(SICI)1096-8628(19960712)64:1<147::AID-AJMG25>3.0.CO;2-M. [DOI] [PubMed] [Google Scholar]
- Neri G., Gurrieri F., Gal A., Lubs H. A. XLMR genes: update 1990. Am J Med Genet. 1991 Feb-Mar;38(2-3):186–189. doi: 10.1002/ajmg.1320380204. [DOI] [PubMed] [Google Scholar]
- Pegoraro E., Schimke R. N., Arahata K., Hayashi Y., Stern H., Marks H., Glasberg M. R., Carroll J. E., Taber J. W., Wessel H. B. Detection of new paternal dystrophin gene mutations in isolated cases of dystrophinopathy in females. Am J Hum Genet. 1994 Jun;54(6):989–1003. [PMC free article] [PubMed] [Google Scholar]
- Pilia G., Hughes-Benzie R. M., MacKenzie A., Baybayan P., Chen E. Y., Huber R., Neri G., Cao A., Forabosco A., Schlessinger D. Mutations in GPC3, a glypican gene, cause the Simpson-Golabi-Behmel overgrowth syndrome. Nat Genet. 1996 Mar;12(3):241–247. doi: 10.1038/ng0396-241. [DOI] [PubMed] [Google Scholar]
- Schimke R. N., Horton W. A., Collins D. L., Therou L. A new X-linked syndrome comprising progressive basal ganglion dysfunction, mental and growth retardation, external ophthalmoplegia, postnatal microcephaly and deafness. Am J Med Genet. 1984 Jan;17(1):323–332. doi: 10.1002/ajmg.1320170125. [DOI] [PubMed] [Google Scholar]
- Schwartz C. E., Ulmer J., Brown A., Pancoast I., Goodman H. O., Stevenson R. E. Allan-Herndon syndrome. II. Linkage to DNA markers in Xq21. Am J Hum Genet. 1990 Sep;47(3):454–458. [PMC free article] [PubMed] [Google Scholar]
- Silver D. N., Lewis R. A., Nussbaum R. L. Mapping the Lowe oculocerebrorenal syndrome to Xq24-q26 by use of restriction fragment length polymorphisms. J Clin Invest. 1987 Jan;79(1):282–285. doi: 10.1172/JCI112795. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sixth International Workshop on Human X Chromosome Mapping 1995. Banff, Alberta, Canada, June 16-18, 1995. Report and abstracts. Cytogenet Cell Genet. 1995;71(4):307–342. doi: 10.1159/000134135. [DOI] [PubMed] [Google Scholar]
- Sutherland G. R. Fragile sites on human chromosomes: demonstration of their dependence on the type of tissue culture medium. Science. 1977 Jul 15;197(4300):265–266. doi: 10.1126/science.877551. [DOI] [PubMed] [Google Scholar]
- Turner G., Collins E., Turner B. Recurrence risk of mental retardation in sibs. Med J Aust. 1971 May 29;1(22):1165–1167. [PubMed] [Google Scholar]
- Wijker M., Ligtenberg M. J., Schoute F., Defesche J. C., Pals G., Bolhuis P. A., Ropers H. H., Hulsebos T. J., Menko F. H., van Oost B. A. The gene for hereditary bullous dystrophy, X-linked macular type, maps to the Xq27.3-qter region. Am J Hum Genet. 1995 May;56(5):1096–1100. [PMC free article] [PubMed] [Google Scholar]
