Meta-analysis of olfactory dysfunction in 22q11.2 deletion syndrome.

A quantitative review of literature concerning olfactory function in 22q11.2 deletion syndrome (22q11DS) patients was performed detailing the scope/magnitude of deficits and probing possible moderators. We searched MEDLINE, EMBASE and PubMed to identify studies for inclusion. Effect sizes were based on differences in psychophysical olfactory tests between 22q11DS patients (n = 194) and typically developing comparison subjects (n = 466). 22q11DS patients exhibited marked olfactory dysfunction (d=-1.11, 95% CI=-1.29<δ<-0.92) that was homogeneous (p = 0.86). Diffuse olfactory deficits were seen which were not moderated by age or sex. 22q11DS patients exhibit large/diffuse deficits in olfactory function that are of a similar magnitude to observed neuropsychological impairments.