Clinical Guidance

Spinocerebellar ataxia type 38 (SCA38) is characterized as a pure cerebellar ataxia with symptoms typically becoming apparent in the fourth decade of life (age range 26-50 years) .

• The most common presenting features are nystagmus (21/21; 100%) and slowly progressive gait ataxia (20/21; 95%).

• With disease progression, cerebellar symptoms such as limb ataxia, dysarthria, dysphagia, and diplopia on the horizontal line may develop.

• In the later stages, ophthalmoparesis followed by ophthalmoplegia may become apparent.

However, visual evoked potentials performed in eight affected individuals were unremarkable .

• Peripheral nervous system involvement is present in the last phase of disease with sensory loss.

• Dementia or extrapyramidal signs are not detected.

Source: GeneReviews — "Spinocerebellar Ataxia Type 38"

Penetrance

Disease penetrance appears to be 100% in both males and females but is age dependent. In individuals with the (p.Gly230Val) pathogenic variant, SCA38 was fully penetrant by age 50 years .

Source: GeneReviews — "Spinocerebellar Ataxia Type 38"

Differential Diagnosis

The inherited spinocerebellar ataxias (SCAs) are a heterogeneous group of neurologic disorders that defy easy differentiation on the basis of clinical criteria alone . For most individuals with SCA, inter- and intrafamilial variability is too great to permit definitive classification without molecular genetic testing. See also Hereditary Ataxia Overview.

Source: GeneReviews — "Spinocerebellar Ataxia Type 38"

Clinical Guidance

Alcohol and medications known to affect cerebellar function should be avoided.

Source: GeneReviews — "Spinocerebellar Ataxia Type 38"

Therapies Under Investigation

A double-blind, randomized, placebo-controlled study followed by an open-label extension phase demonstrated the usefulness of docosahexaenoic acid (DHA) supplementation (600 mg/day) as a safe and effective treatment for SCA38, showing an improvement of clinical symptoms and cerebellar hypometabolism . The long-term safety and efficacy of 600mg/day oral DHA in individuals with SCA38 was further supported by a two-year open-label extension study . No data on the effectiveness of DHA in postponing the signs and symptoms of SCA38 in asymptomatic individuals who have a heterozygous pathogenic variant in ELOVL5 are available. Search ClinicalTrials.gov in the US and EU Clinical Trials Register in Europe for access to information on clinical studies for a wide range of diseases and conditions.

Source: GeneReviews — "Spinocerebellar Ataxia Type 38"