Hereditary Coproporphyria Associated with the Q306X Mutation in the Coproporphyrin Oxidase Gene Presenting with Acute Ataxia

BACKGROUND: Hereditary coproporphyria (HCPO) is a low-penetrance, autosomal dominant, acute hepatic porphyria characterized by the overproduction and excretion of coproporphyrin. The most common neurological manifestations of this entity include peripheral, predominantly motor dysfunction, and central nervous system dysfunction. Ataxia associated with HCPO has not been reported previously. The aim of this article is to report a patient with HCPO presenting with acute ataxia. CASE REPORT: We describe a 44-year-old patient presenting clinically with acute ataxia who was diagnosed with HCPO; mutations were analyzed in the coproporphyrin-oxidase III (CPOX) gene in the patient and in six asymptomatic first-degree relatives. DISCUSSION: The patient was heterozygous for a mutation causing the amino acid exchange Q306X in the CPOX gene. No relatives carried the same or another mutation in the CPOX gene. HCPO should be considered in the differential diagnosis for patients presenting with ataxia.