X-linked mental retardation, short stature, microcephaly and hypogonadism maps to Xp22.1-p21.3 in a Belgian family.
X-linked mental retardation (XLMR) is a heterogeneous disorder that can be classified as either non-specific (MRX), when mental retardation is the only feature, or as syndromic mental retardation (MRXS). Genetic defects underlying XLMR are being identified at a rapid pace, often starting from X-chromosomal aberrations and XLMR families with a well-defined linkage interval. Here, we present a new family with a syndromic form of XLMR, including mild mental retardation, short stature, microcephaly and hypogonadism. Two-point linkage analysis with 24 polymorphic markers spanning the entire X chromosome was carried out. We could assign the causative gene to a 6 cM interval in Xp22.1-p21.3, with a maximum LOD score of 2.61 for markers DXS989 and DXS1061 at theta = 0.00. No mutations were found in the presented family for two known MRX genes mapping to this interval, ARX and IL1RAPL-1. These data indicate that the interval Xp22.1-p21.3 contains at least one additional MRXS gene.
Van Esch
Hilde
H
Centre for Human Genetics, University Hospital Leuven, Herestraat 49, 3000 Leuven, Belgium. hilde.vanesch@med.kuleuven.ac.be
Zanni
Ginevra
G
Holvoet
Maureen
M
Borghgraef
Martine
M
Chelly
Jamel
J
Fryns
Jean-Pierre
JP
Devriendt
Koenraad
K
D000328:Adult; D001530:Belgium; D002874:Chromosome Mapping; D041321:Chromosomes, Human, X / Q000235:genetics*; D005260:Female; D006130:Growth Disorders / Q000235:genetics; D006801:Humans; D007006:Hypogonadism / Q000235:genetics*; D007231:Infant, Newborn; D008126:Lod Score; D008297:Male; D038901:X-Linked Intellectual Disability / Q000235:genetics*; D008831:Microcephaly / Q000235:genetics*; D008875:Middle Aged; D010375:Pedigree; D013577:Syndrome