Regional localization of two genes for nonspecific X-linked mental retardation to Xp22.3-p22.2 (MRX49) and Xp11.3-p11.21 (MRX50).
Two families with nonspecific X-linked mental retardation (XLMR) are presented. In the first family, MRX49, 5 male patients in 2 generations showed mild to moderate mental retardation. Two-point linkage analysis with 28 polymorphic markers, dispersed over the X-chromosome, yielded a maximal LOD score of 2.107 with markers DXS7107 and DXS8051 at theta = 0.0, localizing the MRX49 gene at Xp22.3-p22.2, between Xpter and marker DXS8022. Multipoint linkage analysis showed negative LOD values over all other regions of the chromosome. In the second family, MRX50, 4 males in 2 generations showed moderate mental retardation. Pairwise linkage analysis with 28 polymorphic markers yielded a LOD score of 2.056 with markers DXS8054, DXS1055, and DXS1204, all at theta = 0.0. Flanking markers were DXS8012 and DXS991, situating the MRX50 gene at Xp11.3-Xp11.21, in the pericentromeric part of the short arm of the X chromosome.
Claes
S
S
Center for Human Genetics, University of Leuven, Belgium.
Vogels
A
A
Holvoet
M
M
Devriendt
K
K
Raeymaekers
P
P
Cassiman
J J
JJ
Fryns
J P
JP
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D010375:Pedigree; D011247:Pregnancy; D014960:X Chromosome
D005819:Genetic Markers