Congenital erythropoietic porphyria: Insight into the molecular basis of the disease

Abstract

Congenital Erythropoietic Porphyria (CEP) is a rare inborn error of metabolism charectorised by a deficiency of UROS III enzyme, an important enzyme in the heme biosythetic pathway. It is an autosomal recessive disease and only around 200 cases have been charectorised so far. The clinical presentation, genetic profile and the genotype-phenotype correlation of this disease is complex, and needs to understand completely for proper diagnose of the case and instituting specific therapy. Mutation analysis in the cases of CEP have revealed all types of mutations in the gene including additions, substitutions, insertion and deletions in the gene. Mutations have also been charectorised in the intron-exon junction as well as in the intron regions resulting in truncated gene product and hence a defective enzyme. Mutations in the promoter region too have been charectorised that affect the rate of gene expression. Trans-acting mutations resulting in a phenotype characteristic of CEP have also been recently charectorised. Various study in the molecular basis of the disease have demonstrated that the mutations result in the production of an unstable protein that gets destroyed rapidly resulting a critically low level of the enzyme in the biosystem. Targetting these factors which regulate the rapid degradation of the deformed proteins have been found to improve the clinical profile of the patient and offers potential for future therapy.

Keywords

• Congenital erythropoietic porphyria
• erythrodontia
• mutation
• photodermatitis
• uroporphyrinogen III synthase gene