This is a case report on a 29-year-old left-handed man with depression, anxiety, OCD, and chronic leg pain presenting with 5 years of progressive gait, speech, and cognitive changes. At age 12, he developed nocturnal achy leg pain that improved with movement but not with a “Parkinson’s medication.” Depression and apathy worsened at age 23 after job termination from missing mandatory safety trainings. At age 24, he developed unsteady and slow gait, slowed speech, and abnormal hand movements. At age 27, he was incarcerated for criminally inappropriate behavior. He then developed a hand tremor, slurred speech, mild dysphagia, and began to fall. He had no bowel or bladder dysfunction, dream-enactment behavior, or hyposmia. He had a normal birth and development. He denies significant alcohol, cigarette, or drug use. Family history is notable for suicide in father at age 37 and in paternal grandfather at a young age. His two sisters age 29 and 33 are healthy.

Neurologic exam is notable for slowed responses, fully oriented, and able to follow simple commands. Speech is nasal with lingual dysarthria, he has slowed saccades but full ocular movements and bilateral action-induced facial myoclonus. He has bilateral hand rest tremor with dystonic hand and right arm posturing. He has moderate diffuse rigidity and bradykinesia hyperreflexia, ankle clonus, and left upgoing toe. He has a slow, stooped gait with reduced arm swing bilaterally. No dysmetria or ataxia.

Normal labs include urine copper, ceruloplasmin, Mn level, HIV, RPR, and thyroid studies. EMG/NCS is unremarkable. Brain MRI shows moderate diffuse atrophy and functional dopamine transporter SPECT scan shows abnormal dopamine uptake bilaterally. Parkinsonism genetic panel was negative and whole exome sequencing (WES) revealed a variant of uncertain significance in the TAF1 gene.

Huntington’s disease (HD). HD genetic test: Positive: Alleles 51/21 CAG repeats. 51 CAG repeats in the Huntingtin gene is positive for a diagnosis of HD.