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The common inversion of the Williams–Beuren syndrome region at 7q11.23 does not cause clinical symptoms
Author(s) -
Tam Elaine,
Young Edwin J.,
Morris Colleen A.,
Marshall Christian R.,
Loo Wayne,
Scherer Stephen W.,
Mervis Carolyn B.,
Osborne Lucy R.
Publication year - 2008
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.32360
Subject(s) - williams syndrome , gene duplication , genetics , gene , biology , population , chromosome , medicine , neuroscience , cognition , environmental health
Williams–Beuren syndrome (WBS) is caused by a ∼1.5 million base pair deletion at 7q11.23. A common inversion of the region, WBSinv‐1, exists as a polymorphism but was also found in individuals with WBS‐like features but no deletion, suggesting it could cause clinical symptoms. We performed a full clinical, developmental and genetic assessment of two previously reported individuals with clinical symptoms and WBSinv‐1 but no 7q11.23 deletion. We also examined expression of genes at 7q11.23 in individuals in the general population who have WBSinv‐1. We show that individuals with clinical symptoms and WBSinv‐1 do not show significant clinical or psychological overlap with individuals with WBS. In addition, a 1.3 Mb duplication of part of the velocardiofacial syndrome region on chromosome 22q11.2 was found in one participant with WBSinv‐1 and clinical symptoms. We also demonstrate that individuals with WBSinv‐1 show normal expression of genes from the WBS region. These results suggest that WBSinv‐1 does not cause clinical symptoms and we advise caution when diagnosing individuals with atypical presentation of rare syndromes. Whole genome analysis may reveal previously unidentified copy number variants that could contribute to syndromic features. © 2008 Wiley‐Liss, Inc.