MOLECULAR DEFECTS IN ERYTHROPOIETIC PROTOPORPHYRIA WITH TERMINAL LIVER-FAILURE

We identified two additional mutations in the ferrochelatase gene in t wo Swiss patients with erythropoietic protoporphyria (EPP). Ferrochela tase cDNA from patients was amplified by the polymerase chain reaction (PCR) and subjected to mutation analysis by sequencing PCR products e ither directly or after subcloning. The first patient, who underwent l iver transplantation because of terminal liver failure, was identified as having a single point mutation (C to T) at nucleotide 175 that res ulted in a Gln to stop codon conversion in one allele of the gene. In the second case, in which the patient has so far no liver involvement, a two-base deletion (T899G900) was found in one allele. Frameshift as a result of the deletion creates a stop codon. This study presents tw o new genotypes of EPP, including one with liver failure, a rare and f atal form of EPP.