Benign hereditary chorea (chorea Benign hereditary) - Gen NKX2-1.

Benign hereditary chorea (BHC) is a rare movement disorder characterized by the appearance of not progressive early chorea and not associated with intellectual impairment. Korea primarily affects the head, face and arms.

Other features of the disease include gait difficulties, pyramidal signs, slow movements, abnormal reflexes, myoclonic jerks, dystonia, tremors and tics. Also it described parietal-temporal atrophy front. Other brain regions appear with no identifiable specific astrocitosis without loss of neurons.

This process is due to mutations in the NKX2- 1 gene (TITF1), located on the long arm of chromosome 14 (14q13), encoding a protein initially identified as a specific thyroid transcription factor. The encoded protein binds and thyroglobulin promoter regulates the expression of specific genes but also thyroid shown to regulate the expression of genes involved in morphogenesis. The transcription factor that binds to and activates specific gene promoter as thyroid thyroglobulin, thyroid peroxidase, and thyrotropin receptor. It is crucial in maintaining the phenotype of differentiation of the thyroid. In addition, it can play a role in lung development and surfactant homeostasis. Activates transcription of GnRHR and plays a role in enhancing the circadian oscillation of its gene expression. Represses transcription of circadian NR1D1 transcriptional repressor.

Mutations and deletions in this gene are associated with benign hereditary chorea, choreoathetosis, congenital hypothyroidism, and respiratory distress, and may be associated with thyroid cancer. Found this gene multiple transcript variants encoding different isoforms. This gene shares the symbol 'TTF1' with another gene, factor transcription termination 1, which plays a role in the transcription of ribosomal genes. Changes in the gene truncated protein before or within the homeobox DNA-binding domain, which is suppressed transcriptional activation.

This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to cause the alteration. A few cases have been described with autosomal recessive or X - linked  

Tests in IVAMI: in IVAMI perform detection of mutations associated with benign hereditary chorea, by complete PCR amplification of the exons of the gene NKX2-1, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).