The natural history of retinal degeneration in association with cobalamin C (cbl C) disease

Purpose: To describe the association between retinal degeneration and cobalamin C (cblC) disease and to review previously published ophthalmic data regarding cblC disease. Methods: Descriptive case series of three patients and compilation of all previously reported cases of cblC disease in the ophthalmic literature. Results: All three new cases presented with macular pigmentary changes and showed attenuation of electroretinographic responses. Sequential ERG (electroretinogram) testing in Case 1 demonstrated ERGs that began at the lower limits of normal and became progressively attenuated over time. Conclusions: Cobalamin C disease results in progressive retinal degeneration with its onset in the first few months of life and progressing rapidly over the first few years of life.