Clinical Characteristics

•    The salient features of autosomal recessive spinocerebellar ataxia-20 include severe intellectual disability, absent to severe speech delay and cerebellar ataxia.

•    The presence of coarse facial features in addition to neurological findings provides an important clue for the clinical diagnosis of this disorder.

•    Facial features include arched eyebrows, hypertelorism, epicanthic folds, bulbous nose, long philtrum, thick lips.

•    Most of the individuals are usually normal at birth.

•    Hypotonia with poor deep tendon reflexes is also observed in majority of the individuals.

•    Nystagmus may be present. Some patients have seizures.

•    Other storage signs, hearing deficit, cardiac abnormality and musculoskeletal features are variably present. Hepatosplenomegaly is less common. Kyphoscoliosis may develop.

•    Cerebellar atrophy is not evident at birth but develops later in childhood in addition to pontine involvement and mild cortical atrophy in a few older individuals.