Introduction: ARV1 mutation is known to present as developmental-and-epileptic encephalopathy (DEE)-38, with an expanding phenotypic spectrum since being reported in 2016. Unique clinical features-ophthalmological abnormalities, ataxia, and dystonia, mimicking ataxia telangiectasia. Elevation of alpha-fetoprotein levels (AFP) is an important marker in diagnosing ataxia telangiectasia and ataxia-with-oculomotor apraxia syndromes. ARV1 mutation can also have increased AFP. There are no reports evaluating AFP in cases with ARV1 mutation, which is significant in the context of ocular abnormalities with ataxia.

Methods: The case was evaluated with a detailed history, examination, and investigations. Comprehensive literature review of the reported cases was done.

Results: 14-year-old girl, of consanguineous conception, who presented with seizures, ataxia, and oculomotor apraxia, had a pathogenic missense mutation in ARV1 gene, cerebellar atrophy (Fig), and persistently elevated AFP level (32.2, subsequent year-36 ng/mL). Most cases that present as DEE have a splice-site or frameshift mutation causing severe loss of function. Ataxia has been reported in 8 cases thus far (Table). Missense mutations may have a tendency toward ataxia (as in our case), a milder form of epilepsy, and a longer lifespan compared to premature death in splice-site mutation cases.

Conclusion: Though presentation with DEE is common in ARV1 mutation, a few- with missense mutations, can present with ataxia and ocular abnormalities. All cases with ataxia who have increased AFP levels and seizures should be tested for ARV1 mutation when testing for ataxia genes is negative. Evaluation of AFP must be done in all DEE38 cases, more so in those having ataxia.

Thanuja Basavanagowda
Jawaharlal Nehru Medical College
India

Mahesh Kamate
Jawaharlal Nehru Medical College
India