Dissection of an inverted X(p21.3q27.1) chromosome associated with mental retardation.
In a 6 year old boy referred for mental retardation, fragile X syndrome was ruled out by cytogenetic and molecular analyses. Cytogenetic investigations revealed an inverted X chromosome (p21.3q27.1). A similar chromosomal rearrangement was detected in his mildly mentally retarded mother. Fluorescence in situ hybridization (FISH), using a panel of ordered YAC clones, allowed the identification of YACs spanning both the Xp21.3 and Xq27.1 breakpoints, where many non-specific mental retardation loci have been reported so far. Further investigations by FISH showed that the IL1RAPL1 gene at Xp21.3 was disrupted by the X chromosome inversion and therefore its inactivation may be related to the mental retardation observed in our patients.
Leprêtre
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FRC 3, Institut de Biologie de Lille, Lille, France.
Delannoy
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Froguel
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Vasseur
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Montpellier
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C
D002648:Child; D007446:Chromosome Inversion; D002874:Chromosome Mapping; D041321:Chromosomes, Human, X; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D038901:X-Linked Intellectual Disability / Q000235:genetics*; D010375:Pedigree; D012729:Sex Chromosome Aberrations