A form of progressive myoclonic epilepsy
Type 1:
Clinical features:
Adolescence, severe myoclonus, gradual visual loss, ataxia
Cherry-red spot
No dementia
Genetics:
Autosomal recessive
Chr. 20
Pathology:
Decreased neuraminidase
Type 2:
Clinical features:
adolescence, severe myoclonus, gradual visual loss, ataxia
Cherry-red spot
No dementia
Coarse facies, corneal clouding
Genetics:
Autosomal recessive,
Chr. 10
Pathology:
Decreased neuraminidase & beta-galactosidase