Spinocerebellar ataxia type 2 (SCA2) presenting with ophthalmoplegia and developmental delay in infancy

An 11-year-old boy was evaluated for progressive ataxia, cognitive deterioration, and ophthalmoplegia. The child initially presented with abnormal eye movements at the age of 2 months and was noted to have developmental delay at 6 months. At the age of 7 years, he developed ataxia and cognitive impairment, and subsequently manifested dysphagia and incontinence. The pertinent family history included gait difficulty in the paternal grandmother. At the age of 11, his general physical examination was normal. On neurological examination, he had bilateral external ophthalmoplegia, ataxic dysarthria, dysmetria and tremor in the upper extremities, and marked gait ataxia. An ophthalmological evaluation showed no evidence of pigmentary retinopathy. Brain MRI demonstrated cerebellar, brainstem, and cerebral atrophy. An ataxia panel showed 62 repeats in one allele of the SCA2 gene. Most cases of spinocerebellar ataxia type 2 (SCA2) present between 20 years and 40 years, and affected individuals typically have between 34 and 57 CAG repeats. Neonatal cases of SCA2 have been reported in individuals with over 200 CAG repeats. Childhood SCA2 has been reported previously in two patients but not described clinically. This case broadens the spectrum of the clinical features of infantile-onset SCA2 and highlights the importance of considering this diagnosis in infants and children.