A novel splicing mutation in the ferrochelatase gene responsible for erythropoietic protoporphyria

An aberrant ferrochelatase mRNA lacking exon 7 was found in a patient with erythropoietic protoporphyria (EPP). The exon 7 skipping appears to result from a G >> A transition at position +5 of the donor site of intron 7 of the ferrochelatase gene. The patient is heterozygous for the mutation. Since the patient's paternal half-brother (not available for testing) also has clinically obvious EPP, their father appeared to be the source of the mutant allele. The father was in fact found to be a carrier of the same mutation and his ferrochelatase activity was 35% of normal; however, he is asymptomatic, with only a slightly elevated erythrocyte protoporphyrin level. These findings confirm that the observed mutation is responsible for the defect. The variability in clinical expression of EPP probably reflects the great heterogeneity of the ferrochelatase gene defects and the contribution of additional exogenous and endogenous inducers of latent disease.

Erythropoietic protoporphyria: a study of its psychosocial aspects

Twelve people with erythropoietic protoporphyria (EPP) answered a written questionnaire and were subsequently interviewed. They had all learned to cope with the disease, but found their lives severely restricted. They found that they were seldom understood by others and they suffered considerable physical and psychological distress. Only one subject had any knowledge of the pathophysiological mechanism of EPP. The physician has an important role in recognizing this condition and in providing practical advice and supportive counselling to help patients cope with the disease.

Erythropoietic protoporphyria. 10 years experience

The clinical and laboratory findings in 32 patients with erythropoietic protoporphyria as well as a review of the pertinent literature on this relatively recently described form of porphyria are presented. The disease is thought to be transmitted in an autosomal dominant fashion with variable penetrance and was characterized in these 32 patients by the onset in childhood of burning (97 per cent) and itching (88 per cent) of the skin on exposure to sunlight. This was accompanied by edema (49 per cent) and erythema (69 per cent) of the exposed areas. Vesicles, petechiae and residual scarring occurred less frequently. Associated abnormalities included cholelithiasis (12 per cent), anemia (27 per cent) and abnormal liver function studies (4 per cent). Reports of associated liver disease including nine cases of fatal hepatic failure, are reviewed. Current methods of diagnosis as well as theories of pathophysiology of the disease are presented. Nineteen of 23 of these patients recently treated with beta-carotene responded with significant increase in their tolerance to sun exposure.