BHC begins showing symptoms during childhood, and is commonly a familial disorder. This is a disorder that is correlated with mutations in the thyroid transcription factor gene (TITF-1). Thyroid transcription factor associated with BHC The disorder was discovered in the 1960's. During the time of its discovery, there were no tests that could be used to confirm a diagnosis of the disorder, and the phenotype was not easy to distinguish from other disorders. This resulted in the existence of the disorder being questioned. However, in 2002, the experimentally observed mutation of the gene leading to the BHC phenotype was identified, solidifying<unk>  as a disorder. In 1967, several families were examined and discovered to have movements that were abnormal and random since childhood. These random movements were not violent movements, and gave the person a "general appearance of restlessness." The movements occurred mostly in the hands and arms, and some also experienced them in their tongues, facial muscles, and lower body. Movements in the lower extremities, if severe enough, could cause changes in gait. The families were given a Wechsler Intelligence Scale test, scoring average relative to others in their community. Aside from the aforementioned symptoms, the peoples' physical and neurological characteristics were normal. The observed symptoms were put in the category of<unk> . Researchers made pedigrees of the families they studied and determined that BHC was an autosomal dominant disorder. By studying a Dutch family, the disorder was discovered to be linked to chromosome 14. In 2002, an Italian family was studied, and they had the same linkage to chromosome 14 as the Dutch family did. Looking closer at the region of the chromosome suspected of causing the disorder, researchers discovered that there was a 1.2 Mb deletion in the DNA that resulted in the loss of the TITF-1 gene. This meant that mutations in the TITF-1 gene were likely the reason behind the symptoms of BHC. Currently, BHC is diagnosed through the identification of the phenotypic symptoms with a genetic test to confirm the mutation in the TITF-1 gene.
Benign hereditary chorea
Non-progressive congenital ataxia
Sydenham's chorea
X-linked dystonia parkinsonism
Autosomal recessive cerebellar ataxia
Autosomal recessive cerebellar ataxia type 1
Spinocerebellar ataxia
Huntington's disease-like syndrome