A comparative study of hearing loss in two microdeletion syndromes: velocardiofacial (22q11.2 deletion) and Williams (7q11.23 deletion) syndromes.

Objective: To comprehensively assess auditory impairments in velocardiofacial syndrome (VCFS) and Williams syndrome (WS).

Study Design: Audiologic measurements were conducted with 62 subjects with VCFS and 44 subjects with WS, as well as two control groups consisting of 22 subjects with idiopathic developmental disability and 23 typically developing controls. An association between severity of hearing loss in VCFS and the (158)Val/Met polymorphism of the catechol-O-methyltransferase gene (COMT) was explored.