LAUSR

A 59-year-old woman presented at age 48 years with abnormal hand movements, which became generalized 1 year later, along with a clumsy gait. Two years later, severe apathy and minor auditory hallucinations ensued. Her father died undiagnosed with involuntary movements at age 82 years, and 2 of her 6 sisters have also had a similar clinical picture. Neurologic examination revealed generalized chorea and an unusual dystonic gait pattern remarkably similar to the hobby horse gait, described in DYT-TUBB4A (DYT-4), which is characterized by a toe walking stiff-legged and skipping gait1 (Video 1). Walking backward improved the gait. Diagnostic workup revealed acanthocytes and mild caudate atrophy (Figure 1). A pathogenic 46 CTG/CAG repeat expansion on the JPH3 gene allowed the diagnosis of Huntington disease–like 2, an autosomal dominant Huntington disease phenocopy characterized by chorea, dystonia, and parkinsonism.2 This case expands underlying conditions recognized to cause the HHG (please see the Supplement, links.lww.com/WNL/B931).