Chapter 33 - Spinocerebellar ataxia type 11

Abstract

Clinical characteristics Spinocerebellar ataxia type 11 (SCA11) is characterized by progressive cerebellar ataxia and abnormal eye signs (jerky pursuit, horizontal and vertical nystagmus). Pyramidal features are seen on occasion. Peripheral neuropathy and dystonia are rare. Six families have been reported to date, one each from the UK, Pakistan, France, Germany, Denmark, and China. Age of onset ranged from early childhood to the mid-40s. Life span is thought to be normal. Diagnosis/testing The diagnosis of spinocerebellar ataxia type 11 (SCA11) is established in a proband with a heterozygous pathogenic variant in TTBK2 identified by molecular genetic testing. Management Treatment of manifestations: Management is supportive; there are no known disease-modifying treatments to date. Physiotherapy and assessment for assistive devices for ambulation; occupational therapy, including home adaptations; speech and language therapy for dysarthria and dysphagia; ankle-foot orthotics if required and good foot care for those with neuropathy; treatment per ophthalmologist for vision issues; prism glasses may be helpful for diplopia. Surveillance: Annual neurologic evaluation; evaluations with physiotherapist, occupational therapist, speech and language therapist, and ophthalmologist as indicated. Genetic counseling SCA11 is inherited in an autosomal dominant manner. The proportion of SCA11 caused by de novo mutation is unknown. Each child of an individual with SCA11 has a 50% chance of inheriting the pathogenic variant. Prenatal diagnosis for at-risk pregnancies is possible if the diagnosis has been established by molecular genetic testing in an affected family member.