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

Abstract

Background Williams syndrome (WBS) is a genetic multisystem disorder. The main symptom is borderline (intelligence quotient, IQ 70–79) or abnormally low intelligence (IQ < 70). According to earlier studies young individuals with WBS demonstrate generally a slightly higher verbal IQ (VIQ) compared to performance/nonverbal IQ (PIQ). WBS was recognized as a distinct entity already about 60 years ago, but still cognition in adults with WBS is poorly known. Methods We followed 25 adults (age at baseline 19–68, median 38) with genetically confirmed WBS for about 20 years. The study subjects underwent medical and neuropsychological assessments at the baseline and at the end of follow‐up. Results The mean VIQ remained quite stable from early adulthood up to 40 years of age after which it declined. The mean PIQ kept on improving from early adulthood until 50 years 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. Conclusions In 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.

Neuropsychological study in 19 French patients with White‐Sutton syndrome and POGZ mutations

“…It is commonly understood that cognitive deficits in patients with ID develop during developmental years at individually varying rate regardless of the etiology. Furthermore, the course of cognition could vary depending on the syndrome 12 . In our study, patients were assessed at different ages.…”

Ageing and cognition in men with fragile X syndrome

“…A 20‐year follow‐up study of people with WS showed that verbal performance strengthened in early adulthood and remained relatively stable up to the age of 45–50 years but then declined rather rapidly. However, the so‐called fluid, non‐verbal abilities were found to remain stable until at least the age of 55 years (Sauna‐aho et al, 2018; Sauna‐aho, Bjelogrlic‐Laakso, Siren, Kangasmäki, & Arvio, 2019). Compared to people with WS, the fluid, non‐verbal cognitive abilities of FXS men seem to decline earlier.…”

Screening of dementia indicating signs in adults with intellectual disabilities

“…Our earlier cross‐sectional as well as longitudinal studies have focused on three genetic syndromes, that is Down, fragile X and William syndromes (Arvio, 2016; Arvio & Luostarinen, 2016; Sauna‐aho et al, 2018, 2019, 2020). The association between Down syndrome and Alzheimer's disease has been known for a long time (Takashima, 1997).…”

“…Since the early 1990 s, it has been recognized that adults with intellectual disability who are affected by dementia need special care (Janicki & Keller, 2015; McCarthy & Mullan, 1996). Our earlier studies suggest that the dementia rates in intellectual disability excluding Down syndrome and compared to the general population may be either higher, lower or similar depending on the aetiology of intellectual disability (Arvio, 2016; Arvio & Luostarinen, 2016; Sauna‐aho et al, 2018, 2019, 2020). The purpose of the present cross‐sectional study was to screen dementia signs in different age groups of adults with intellectual disability.…”