Spinocerebellar Ataxia Type 28

Spinocerebellar ataxia type 28 (SCA28) is a very rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I; see this term). It is characterized by juvenile onset, slowly progressive cerebellar ataxia due to Purkinje cell degeneration.

Epidemiology

Prevalence is unknown. SCA28 accounts for approximately 1.5% of all European cases of ADCA.

Clinical description

The mean age of symptom onset was 19.5 years in the original kindred. Some patients show cognitive impairment. In more advanced stages of the disorder, ophthalmoparesis, slowed saccades, ptosis and pyramidal signs are reported. Patients can walk unassisted until the 7th decade of life. Life-threatening status epilepticus and intractable seizure or severe dysphagia are rare.

Etiology

SCA28 is caused by mutations in the AFG3L2 gene located to chromosome 18p11.21.

Genetic counseling

SCA28 is inherited autosomal dominantly and genetic counseling is possible.