Abstract / Summary
Pathogenic variants in VPS13A cause chorea-acanthocytosis, classically presenting as chorea, dystonia, and orolingual dyskinesias. Parkinsonism is an underreported presenting symptom, particularly in the absence of these classical features, and may lead to misdiagnosis. We report the case of a 52-year-old man evaluated for heart transplantation, during which the neurology service was consulted for recently diagnosed Parkinson's disease to inform transplant candidacy. His history revealed progressive gait difficulty, falls, slurred speech, nonresponse to levodopa, and absence of resting tremor or other involuntary movements. Initial examination revealed moderate hypophonic dysarthria, reduction in facial expression, asymmetric rigidity and bradykinesia, and severe postural instability. Magnetic resonance imaging of the brain revealed basal ganglia atrophy, especially in the bilateral caudate nuclei. Bloodwork revealed a normal creatine kinase level, elevated ferritin, copper, and ceruloplasmin levels, and acanthocytosis. Genetic testing revealed heterozygous pathogenic variants in VPS13A, c.7420-2A>C, and c3961-2A>G, consistent with autosomal recessive chorea-acanthocytosis. Chorea-acanthocytosis, as discovered in this patient via genetic testing, may present without typical symptoms and lead to misdiagnosis as idiopathic Parkinson's disease. Presence of atypical parkinsonian features, acanthocytes on peripheral blood smear, and basal ganglia abnormalities on structural imaging should raise the index of suspicion for this rare disorder.