Severe expressive-language delay related to duplication of the Williams-Beuren locus.
The Williams-Beuren syndrome (WBS) locus, at 7q11.23, is prone to recurrent chromosomal rearrangements, including the microdeletion that causes WBS, a multisystem condition with characteristic cardiovascular, cognitive, and behavioral features. It is hypothesized that reciprocal duplications of the WBS interval should also occur, and here we present such a case description. The most striking phenotype was a severe delay in expressive speech, in contrast to the normal articulation and fluent expressive language observed in persons with WBS. Our results suggest that specific genes at 7q11.23 are exquisitely sensitive to dosage alterations that can influence human language and visuospatial capabilities.
Somerville
Martin J
MJ
Department of Medical Genetics, University of Alberta, Edmonton, Alta., Canada.
Mervis
Carolyn B
CB
Young
Edwin J
EJ
Seo
Eul-Ju
EJ
del Campo
Miguel
M
Bamforth
Stephen
S
Peregrine
Ella
E
Loo
Wayne
W
Lilley
Margaret
M
Pérez-Jurado
Luis A
LA
Morris
Colleen A
CA
Scherer
Stephen W
SW
Osborne
Lucy R
LR
D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications; D002648:Child; D002872:Chromosome Deletion; D002897:Chromosomes, Human, Pair 7; D005260:Female; D018628:Gene Dosage; D020440:Gene Duplication; D006801:Humans; D007805:Language Development Disorders / Q000150:complications / Q000235:genetics*; D008297:Male; D010641:Phenotype; D013064:Speech Disorders / Q000235:genetics*