Deletion of distal promoter of VCXA in a patient with X-linked ichthyosis associated with borderline mental retardation.
BACKGROUND
X-linked ichthyosis (XLI) is caused by deficiency of steroid sulfatase (STS) activity. About 90% XLI patients have large deletions involving the entire STS gene and flanking regions. Recently, VCXA, which is located approximately 0.7Mb telomeric to the STS gene, was reported as a candidate gene for mental retardation (MR) in patients with XLI.


OBJECTIVE
To delineate the X-chromosomal deletion of a XLI patient with borderline mental retardation.


METHODS
We carried out FISH analysis to show that the whole STS gene is deleted, and PCR analysis for fine-scale deletion mapping.


RESULTS
The deleted segment is approximately 1.6Mb in size, and includes the entire STS and VCXB1 genes. VCXA itself is intact, but its promoter is deleted.


CONCLUSIONS
A deletion that includes the VCXA promoter is associated with borderline mental retardation in a patient with XLI.
Hosomi
Naoko
N
Division of Dermatology, Kashiwara Municipal Hospital, Kashiwara, Japan. nhosomi@msic.med.osaka-cu.ac.jp <nhosomi@msic.med.osaka-cu.ac.jp>
Oiso
Naoki
N
Fukai
Kazuyoshi
K
Hanada
Kazushi
K
Fujita
Hiroko
H
Ishii
Masamitsu
M
D000328:Adult; D017353:Gene Deletion; D006801:Humans; D016114:Ichthyosis, X-Linked / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics* / Q000523:psychology; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012720:Severity of Illness Index; D043266:Steryl-Sulfatase / Q000235:genetics
D009687:Nuclear Proteins; C404411:VCX protein, human; D043266:Steryl-Sulfatase