Acute intermittent porphyria and disturbances in amino-acid metabolism in a psychiatric in-patient population

Abstract

SummaryIn recent years an enhanced catabolism of serine, with or without the existence of porphyria, has been demonstrated in relation to a specific subtype of psychosis, according to ICD-10 criteria, the acute polymorphic psychosis with or without symptoms of schizophrenia. Since sensory perceptual distortions play a key role in the symptomatology, patients with this disorder are referred to as Acute Polymorphic Psychosis plus psychosensory phenomena (APP+). In a retrospective study, including a total of 140 chronic psychiatric patients, we investigated the prevalence of Acute Intermittent Porphyria (AIP) and APP+. No subjects with AIP were found. In two patients APP+ could be demonstrated, based on both clinical characteristics and positive biochemical markers, ie lowered plasma serine concentration and increased TSM-ratio (100 × Taurine (μmol/l)/Serine concentration * Methionine concentration). In three patients the psychotic disorder was suspected to be present. It is concluded that careful psychiatric diagnosing may reveal specific psychotic disorders with a distinct biological pathogenetic factor, ie a disturbed serine metabolism.