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. CONCLUSION: A deletion that includes the VCXA promoter is associated with borderline mental retardation in a patient with XLI.
BACKGROUND:X-linked ichthyosis (XLI) is caused by deficiency of steroid sulfatase (STS) activity. About 90% XLIpatients 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 XLIpatient 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. CONCLUSION: A deletion that includes the VCXA promoter is associated with borderline mental retardation in a patient with XLI.
Authors: Jonathan D J Labonne; Terri M Driessen; Marvin E Harris; Il-Keun Kong; Soumia Brakta; John Theisen; Modibo Sangare; Lawrence C Layman; Cheol-Hee Kim; Janghoo Lim; Hyung-Goo Kim Journal: J Clin Med Date: 2020-01-19 Impact factor: 4.241