Prevalence of acute intermittent porphyria in a Mexican psychiatric population

Background. Acute intermittent porphyria is a hereditary error of porphyrin metabolism in which the main metabolic defect is caused by a decrease in p orphobilinogen deaminase activity. Previous work has demonstrated a higher prevalence of acute intermittent porphyria in the psychiatric patient popul ation than in the general population. The goal of this study was evaluate 3 00 psychiatric patients and 150 control subjects to detect acute intermitte nt porphyria by measurement of porphobilinogen (PBG) deaminase activity in blood. Methods. Screening for porphobilinogen deaminase activity was carried out b y fluorometric measurement of porphyrins synthesized during 1 h in blood an d the measurement of delta-aminolevulinic acid and porphobilinogen in urine . Results. We found two psychiatric patients, one male and one female, with d ecreased por porphobilinogen deaminase activity. When the families of these patients were studied, one brother was found to have an abnormality. Among controls, a woman was found to have the abnormality and her father was fou nd to have typical features of the disease. Conclusions, These results indicate a prevalence of porphyria in Mexican ps ychiatric patients similar to controls, and that measurement of PEG deamina se activity is a good tool for defining acute intermittent porphyria carrie rs. (C) 2000 IMSS. Published by Elsevier Science Inc.