Cerebellar ataxia and ocular conjunctival telangiectasia: Look again

A 14-year-old boy presented with progressive incoordination and cognitive issues. Family history was negative for any neurological condition. Examination revealed cerebellar ataxia and cognitive impairment as well as prominent ocular conjunctival telangiectasia (figure), which made ataxia-telangiectasia, a recessive disorder, a plausible diagnostic hypothesis. Serum alpha-fetoprotein levels were however normal. At follow-up, he was accompanied by his father, who was found to have significant gait ataxia – warranting genetic testing to assess for an autosomal dominant spinocerebellar ataxias. Abnormal CAG repeats in the ATXN3 gene were identified in the pathogenic range(31/52 CAG repeats) consistent with spinocerebellar ataxia type 3/ Machado-Joseph disease (SCA3). Ocular conjunctival telangiectasia can be found in different diseases, including ataxia-telangiectasia (ATM syndrome), generalized essential telangiectasia, with conjunctival involvement, and hemorrhagic telangiectasia of Rendu-Osler, among others1,2. Ocular conjunctival telangiectasia can be found in association with cerebellar ataxia, even though they may not share a common cause.