Regional localization of an X-linked mental retardation gene to Xp21.1-Xp22.13 (MRX38).
A gene responsible for X-linked mental retardation with macrocephaly and seizures (MRX38) in a family with five affected males in three generations was localized to Xp21.1-p22.13 by linkage analysis. Recombination events placed the gene between DXS1226 distally and DXS1238 proximally, defining an interval of approximately 14 cM. A peak lod score of 2.71 was found with several loci in Xp21.1 (DXS992, DXS1236, DXS997, and DXS1036) at a recombination fraction of zero. The map intervals of 5 X-linked mental retardation loci, MRX2 (Xp22.1-p22.2), MRX19 (Xp22), MRX21 (Xp21.1-p22.3), MRX29 (Xp21.2-p22.1), and MRX32 (Xp21.2-p22.1), and two syndromal mental retardation loci, Partington syndrome (PRTS; Xp22) and Coffin-Lowry syndrome (CLS; Xp22.13-p22.2), overlap this region. As none of these display the same phenotype seen in the family reported here, this X-linked mental retardation locus may represent a new entity.
Schutz
C K
CK
Department of Biology McMaster University, Hamilton, Ontario, Canada.
Ives
E J
EJ
Chalifoux
M
M
MacLaren
L
L
Farrell
S
S
Robinson
P D
PD
White
B N
BN
Holden
J J
JJ
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000002:abnormalities; D002874:Chromosome Mapping; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D010375:Pedigree; D011995:Recombination, Genetic; D012640:Seizures / Q000235:genetics; D014960:X Chromosome