Benign hereditary chorea

Benign hereditary chorea (BHC) is a rare movement disorder that beginsin infancy or childhood. Signs and symptoms in infants may include lowmuscle tone, involuntary movements (chorea), lung infections, andrespiratory distress. Signs and symptoms in children may include delayedmotor and walking milestones, jerky muscle movements (myoclonus), upper limb dystonia,motor tics, and vocal tics. The chorea often improves with time. Insome cases, myoclonus persists or worsens. Children with BHC can havenormal intellect, but may have learning and behavior problems. Othersigns and symptoms include thyroid problems (e.g., hypothyroidism)and lung disease (e.g., recurring infections). Treatment is tailoredto each child. Tetrabenazine and levodopa have been tried in individualcases with some success. BHC is caused by mutations in the NKX2-1 gene(also known as the TITF1 gene). It is passed through families in an autosomal dominant fashion.