Human protoporphyria: genetic heterogeneity at the ferrochelatase locus
Abstract:Inherited deficiency of ferrochelatase results in erythropoietic protoporphyria (EPP). Genetic heterogeneity at the locus for human ferrochelatase was investigated. Analysis of genomic DNA of patients with EPP and of control subjects by restriction endonuclease techniques using ten different enzymes detected polymorphisms only at sites recognized by EcoRI, HincII, PstI and TaqI. None of these polymorphisms alone was specific for expression of the disease since each was observed in control subjects as well. Three of these polymorphisms (at EcoRI, HinII and PstI sites) were always associated, indicating linkage. These and other studies demonstrate that the ferrochelatase gene is markedly heterogeneous. It is not yet clear whether some of the mutations associated with these polymorphisms contribute to expression of EPP.
Document Type: Original Article
Affiliations: 1: Department of Dermatology, New York Medical College, Valhalla, New York 2: Division of Pediatric Hematology-Oncology, Columbia University College of Physicians and Surgeons, New York, New York, USA
Publication date: February 1, 1995