Retinal Imaging in Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay

A case is described of autosomal recessive spastic ataxia of Charlevoix-Saguenay. Genetic analysis has shown that two mutant genes encoding the sacsin protein have been inherited one from each parent. In the proband the thickness of the nerve fibre layer is quantified using optical coherence tomography. An abnormally thick retinal nerve fibre layer has been previously described in this condition, ascribed to hypermyelination; the authors suggest that there is no evidence of abnormal myelination as the thickened nerve fibre layer is not opaque. Lesser degrees of nerve fibre layer thickening are seen in other family members who do not show any of the phenotypic features of the disorder.