Acute intermittent porphyria: prevalence of mutations in the porphobilinogen deaminase gene in blood donors in France

Objectives. Acute intermittent porphyria (AIP) is an autosomal dominant disorder resulting from a 50% deficiency in porphobilinogen deaminase (PBG deaminase). The true prevalence in the general population of mutations in the PEG deaminase gene capable of causing ALP is unknown. However, it is important to identify asymptomatic carriers of AIP mutations because all are at: risk to have an acute attack. Design. We measured erythrocyte PEG deaminase from 3350 healthy blood donors. When a clear cut deficiency (< mean minus 2.5 SD) was found, the PEG deaminase gene was analysed by molecular biology technics. Subjects. Four subjects with PEG deaminase deficiency were identified. Two had mutations in the PEG deaminase gene which are known to cause AIP. Conclusion. We conclude that, in France, the mutations of the PEG deaminase gene show a high prevalence in the healthy population If only these two confirmed latent cases are used for the calculation, in France the minimal prevalence of the AIP gene is 1:1675.