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Late-onset cobalamin-C disorder: a challenging diagnosis
Tawfeg I Ben-Omran1, Hubert Wong, Susan Blaser
1Division of Clinical and Metabolic Genetics, University of Toronto, Toronto, Canada.
Abstract:
Cobalamin-C (cblC) disease is a rare autosomal recessive disorder due to defective intracellular cobalamin metabolism. There are few (13) reported patients of the late-onset presentation of cblC disease with paucity of detailed clinical descriptions. This results in this condition being easily missed. In this report, we describe clinical and biochemical findings of two unrelated patients with late-onset cblC disease who presented with neuropsychiatric symptoms. Serial MRI images are provided for one of these patients. Presumptive diagnosis was made with urine and plasma biochemical markers and confirmed with fibroblast analysis. These patients illustrate the challenging diagnosis of this disease and also report on the rare associated findings of vasculopathy and mitochondrial respiratory chain dysfunction. Mutation analysis of the MMACHC gene showed that both patients were homozygous for 394C --> T which suggests a founder effect.
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Erythrocyte disorders can be broadly categorized into two main types: anemic and polycythemic conditions.
A low oxygen-carrying capacity of the blood due to the loss, lower production, or destruction of erythrocytes is termed anemia. Hemorrhagic anemia, for example, occurs when bleeding from an external wound or internal ulcer reduces erythrocyte counts.
On the other...