Psychiatric Presentation of Hereditary Coproporphyria with Coproporphyrinogen Oxidase Gene Mutation c.734 C>T: A Case Report.

Introduction: Porphyrias constitute a collection of hereditary metabolic disorders arising from disturbances in the enzymatic activities inherent to the heme biosynthetic pathway. Eight subtypes of porphyria, each associated with enzymes in the heme biosynthesis pathway, have been identified. Hereditary coproporphyria is one of the porphyria subtypes characterized by neuropsychiatric clinical features. It develops as a result of a deficiency in coproporphyrinogen oxidase enzyme activity. Consequently, an accumulation of coproporphyrin and its precursor metabolites is observed. Hereditary coproporphyria exhibits autosomal dominant inheritance. Following clinical suspicion, a diagnosis is made with biochemical and genetic tests. The presence of nonspecific symptoms and the lack of consideration for porphyria in differential diagnosis complicate the diagnosis. Case: An 18-year-old male patient was referred to our psychiatry clinic only with psychiatric complaints. The mental status examination revealed affective signs, along with visual hallucinations and delusions. Blood tests and cranial scans at admission showed no abnormalities. After initiating treatment with valproic acid and olanzapine for a presumptive diagnosis of bipolar I disorder, a manic episode with psychotic features, the patient's general medical condition worsened. During clinical observation, the appearance of neurological and gastrointestinal system findings led to a reconsideration of the diagnosis, and porphyria was considered. Urine tests revealed elevated levels of porphyrin intermediates. The diagnosis of hereditary coproporphyria was confirmed by genetic testing, which identified the c.734 C>T mutation in the coproporphyrinogen oxidase gene. Symptomatic relief was observed following a carbohydrate-rich diet without the need for psychotropic treatment. Conclusion: Although their subtypes exhibit distinct clinical features, porphyrias typically present with involvement of multiple systems. Cases that initially present with symptoms specific to a single system can pose diagnostic challenges. In our case report, we aimed to present the psychiatric onset of hereditary coproporphyria, a rare subtype of porphyria known for its potentially fatal attacks when untreated.