Spinocerebellar ataxia 11 (SCA11) – TTBK2 gene.


Spinocerebellar ataxia type 11 (SCA11), is a neurodegenerative disorder characterized by progressive ataxia and atrophy of the cerebellum and brainstem.

This process develops with cerebellar signs such as dysarthria and progressive ataxia, which eventually results in difficulty walking and loss of balance, as well as abnormalities in eye movement (uneven search, horizontal and vertical nystagmus and ophthalmoplegia), due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. Pyramidal signs, such as hyperreflexia, mainly in the lower extremities, with positive signs of Babinski are occasionally present. Rarely, dystonia and peripheral neuropathy have been reported. The disease progresses slowly with dysphagia that occurs later in the course of the disease.

This process is due to mutations in the TTBK2 gene (tau tubulin kinase 2), located on the long arm of chromosome 15 (15q15.2), which encodes a serine-threonine kinase that supposedly phosphorylates the tau and tubulin proteins. This protein acts as a key regulator of ciliogenesis. The serine-threonine kinase controls the onset of ciliogenesis by joining the distal end of the basal body and promoting the elimination of CCP110, which closes the centriole, which leads to the recruitment of IFT proteins, to constitute the ciliary axoneme.

This disease is inherited with an autosomal dominant pattern, which means that one copy of the altered gene in each cell is sufficient for the disease to be expressed. In most cases, an affected person has a father with the disease.

Tests performed in IVAMI: in IVAMI we detect the mutations associated with spinocerebellar ataxia type 11 (SCA11), by complete PCR amplification of the exons of the TTBK2 gene, and subsequent sequencing.

Recommended samples: blood taken with EDTA for separation of blood leukocytes, or card impregnated with dried blood sample (IVAMI can mail the card to deposit the blood sample).