Genetic analysis in a boy aged 8 years 10 months with severe delay in expressive language and orofacial dyspraxia uncovered reciprocal duplications of the Williams-Beuren syndrome (WBS) locus at chromosome 7q11.23, in a report from the University of Alberta, and other centers in Canada, USA, and Spain. The patient had mental and growth retardation, attention deficit hyperactivity disorder (ADHD), and dysmorphic features, including dolichocephaly, narrow forehead, long eyelashes, broad nose, rotated ears, short philtrum, thin lips, dental malocclusion, high palate, and bilateral simian creases. A Peabody Picture Vocabulary Test score for receptive vocabulary was low average (age equivalent, 6 years 10 months), and in contrast, a standard score on an Expressive Vocabulary Test was in the severe-impairment range (age equivalent, 2 years 3 months). Expressive language delay and speech dyspraxia, which are not characteristic of WBS, appeared to be related to the duplication of the WBS locus and the region on the long arm of chromosome 7 commonly deleted in WBS. The patient had strong abilities in visuospatial construction, and he often resorted to drawing when unable to express his thoughts. This finding was also in contrast to patients with WBS who have weak visuospatial abilities. The authors propose that specific genes at 7q11.23 are sensitive to dosage alterations that influence language development and visuospatial function. [1]

COMMENT. This paper describes an expressive language phenotype associated with dup7q11.23, located in the long q arm of chromosome 7, at the region commonly deleted in WBS. The characteristic facial phenotype is also shared with a previously described syndrome of delay in expressive language and supernumerary ring chromosome 7. This consists of a high, broad nose, posteriorly rotated ears, high-arched palate, and short philtrum. These facies coupled with expressive language delay should prompt genetic testing for duplication of the WBS region.

An editorial perspective “On genes, speech, and language” [2] refers to a specific gene, FOXP2, located in chromosome 7q31, implicated previously in verbal dyspraxia and orofacial dyspraxia (cited by Somerville et al) [3]. The above study that identifies a second locus on chromosome 7 associated with language delay and oromotor dyspraxia emphasizes the potential of using molecular diagnostics for early identification of children at increased risk of language and speech impairment.