Clinical Trial Review

The initial objective of this protocol is to assemble a well-documented group of patients with confirmed diagnoses of the erythropoietic protoporphyrias for clinical, biochemical, and genetic studies. The long-term objectives are (1) to conduct a longitudinal investigation of the natural history, complications, and therapeutic outcomes in people with erythropoietic protoporphyria; (2) to systematically investigate the psychological effects of the erythropoietic protoporphyrias on children and adults; and (3) to investigate the correlation between the identified genotypes and the resulting clinical presentation, also determining the possible interaction of other genetic markers.The porphyrias are a group of rare metabolic diseases that may present in childhood or adult life and are due to deficiencies of enzymes in the heme biosynthetic pathway. The most common manifestations are related to accumulation of intermediates in the pathway and usually occur as acute neurological attacks (as in the acute or hepatic porphyrias), or cutaneous photosensitivity (as in the cutaneous porphyrias, including the erythropoietic protoporphyrias).

The risk of disability or death from these disorders is significant, in part because diagnosis is often delayed due to lack of adoption of diagnostic testing in clinical practice. Moreover, the natural history of these disorders is not well described and it is not known what determines differences in outcomes. New therapies are needed. For existing therapies, high-quality evidence on short- and long-term efficacy and safety is generally lacking. Therefore, the purpose of this study is to provide a better understanding of the natural history of these disorders, as affected by available therapies, and to aid in developing new forms of treatment.