Pericentromeric genes for non-specific X-linked mental retardation (MRX)
- Univ. of Adelaide (Australia)
- Prince of Wales Children`s Hospital, Randwick (Australia)
Extensive linkage analysis in three families with non-specific X-linked mental retardation (MRX) have localized the gene in each family to the pericentromeric region of the chromosome. The MRX17 gene is localized with a peak lod of 2.41 ({theta} = 0.0) with the trinucleotide repeat polymorphism at the androgen receptor (AR) gene locus. The gene lies in the interval between the markers DSX255 and DXS990, as defined by recombinants. The MRX18 gene maps to the interval between the markers DXS538 and DXS1126, with a peak lod score of 2.01 ({theta} = 0.0) at the PFC gene locus. In the third family (Family E) with insufficient informative meioses for assignment of an MRX acronym, the maximum lod score is 1.8 at a recombination fraction of zero for several marker loci between DXS207 and DXS426. Exclusions from the regions of marker loci spanning Xq support the localization of the MRX gene in Family E to the pericentromeric region. Localizations of these and other MRX genes have determined that MRX2 and MRX19 map to distal Xp, MRX3, and MRX6 map to distal Xq, whilst the majority cluster in the pericentromeric region. In addition, we confirm that there are at least two distinct MRX genes near the centromere as delineated by the non-overlapping regional localizations of MRX17 and MRX18. Determination of these non-overlapping localizations is currently the only means of classifying non-syndromal forms of mental retardation and determining the minimum number of MRX loci. 27 refs., 14 figs., 5 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 62056
- Journal Information:
- American Journal of Medical Genetics, Journal Name: American Journal of Medical Genetics Journal Issue: 4 Vol. 51; ISSN 0148-7299; ISSN AJMGDA
- Country of Publication:
- United States
- Language:
- English
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