chorea, benign familial

Benign hereditary chorea (BHC) is a rare movement disorder primarily characterized by involuntary movements (chorea) that typically begin in infancy or childhood. It is inherited in an autosomal recessive manner, meaning that both parents must carry the gene for a child to be affected. The disorder may present with low muscle tone, delayed motor milestones, and myoclonus. Children may also experience upper limb dystonia and tics. Although clinical features are not systematically documented, thyroid problems and respiratory issues are also noted. The underlying genetic basis is linked to mutations in the NKX2-1 gene, although specific variants have not been identified in this case.

Documentation for benign hereditary chorea is limited due to its rarity, affecting fewer than a few hundred individuals worldwide. This extreme rarity has resulted in a lack of systematic clinical studies and comprehensive phenotype documentation. Additionally, the genetic basis of the condition is still being explored, which contributes to the challenges in understanding its clinical presentation.