SORL1 and Alzheimer disease: A previous study showed that the SORL1 variants p.T588I, p.A528T, and p.T947 M were found in AD patients who display parkinsonian features.[9] Then Maple et al found that the common SORL1 variant was associated with increased risk of dementia in Parkinson disease.[10] These studies indicated that SORL1 mutations could influence the occurrence or progression of both cognitive impairment and parkinsonian symptoms.