Prominent Psychiatric Symptoms and Glucose Hypometabolism in a Family With a Snca Duplication

The genomic duplication of the α-synuclein gene ( SNCA ) has been shown to cause familial parkinsonism.1,2 Although patients with SNCA duplication often exhibit similar features to those with idiopathic Parkinson disease (PD), we and others previously reported that patients with SNCA duplication may develop the phenotype of PD dementia (PDD).3,4 We identified a new family with SNCA duplication who developed parkinsonism, visual hallucination, and cognitive fluctuation, which are the characteristic phenotypes in patients with dementia with Lewy bodies (DLB). A PET study of this family revealed a pattern of cerebral glucose hypometabolism similarly described in patients with DLB.5 ### Case reports. #### Patient 1. The proband had symptoms of generalized anxiety disorder including palpitation, restlessness, sensation of dyspnea, and excessive worry 5 years prior to his first visit to our hospital with complaint of gait disturbance at age 47 years. On neurologic examination, poor facial expression, rigidity, and bradykinesia in his right extremities were noted. His cognitive function was apparently normal. At age 49, his bradykinesia has progressed and shuffling gait, impaired postural balance, and postural tremor were present. These symptoms were improved by treatment with l-dopa and cabergoline. At age 50, he developed visual hallucinations and delirium followed by obvious deficits in attention and verbal fluency, and prosopagnosia was occasionally noted. These psychiatric symptoms including his hallucinations were apparently unrelated to l-dopa therapy. He also exhibited fluctuating cognitive decline, as shown by his Mini-Mental State Examination (MMSE) score of 24 and Raven Colored Progressive Matrices score of 27. #### Patient 2. The mother of the proband …