What is (are) Benign hereditary chorea ?
Benign hereditary chorea (BHC) is a rare movement disorder that begins in infancy or childhood. Signs and symptoms in infants may include low muscle tone, involuntary movements (chorea), lung infections, and respiratory distress. Signs and symptoms in children may include delayed motor and walking milestones, jerky muscle movements (myoclonus), upper limb dystonia, motor tics, and vocal tics. The chorea often improves with time. In some cases, myoclonus persists or worsens. Children with BHC can have normal intellect, but may have learning and behavior problems. Other signs and symptoms include thyroid problems (e.g., hypothyroidism) and lung disease (e.g., recurring infections). Treatment is tailored to each child. Tetrabenazine and levodopa have been tried in individual cases 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.