Cognition in adults with Williams syndrome-A 20-year follow-up study

BackgroundWilliams syndrome (WBS) is a genetic multisystem disorder. The main symptom is borderline (intelligence quotient, IQ 70-79) or abnormally low intelligence (IQ MethodsWe followed 25 adults (age at baseline 19-68, median 38) with genetically confirmed WBS for about 20years. The study subjects underwent medical and neuropsychological assessments at the baseline and at the end of follow-up. ResultsThe mean VIQ remained quite stable from early adulthood up to 40years of age after which it declined. The mean PIQ kept on improving from early adulthood until 50years of age after which it gradually declined. At the end of the study, all study subjects had at least two longstanding health problems out of which hypertension, psychiatric disorder, and scoliosis or kyphosis occurred most frequently. At end of the study, two patients suffered from vascular dementia. Seven patients died during the follow-up. ConclusionsIn adults with WBS, the course of cognition is uneven across the cognitive profile. Their verbal functions both develop and deteriorate earlier than performance/nonverbal functions. Frequent somatic co-morbidities may increase risk to shortened life span.Peer reviewe