title: Congenital Erythropoietic Porphyria: Mutation of the Uroporphyrinogen III Cosynthase Gene in a Vietnamese Patient.
abstract: Congenital erythropoietic porphyria (CEP) arises from an autosomal recessive inherited disorder of the porphyrin metabolism, which leads to the accumulation of uroporphyrinogen I in bone marrow, skin and several other tissues by a deficiency of uroporphyrinogen III cosynthase (UROS). We studied a Vietnamese patient and her family suffering from severe cutaneous photosensitivity with skin fragility, bullous lesions and hypertrichosis on light-exposed areas. A missense mutation in the UROS gene was identified as a transversion of G to T at nucleotide 11,776, resulting in a substitution of valine by phenylalanine at codon 3 of exon 2. The patient showed a homozygous mutant profile, and the heterozygous state was observed in the parents. The activity of mutated UROS expressed in Escherichia coli was less than 16.1% that of the control, indicating that the markedly reduced activity of UROS is responsible for CEP. We described for the first time a mutation in the UROS gene in a Southeast Asian patient and a molecular diagnosis for the identification of clinically asymptomatic heterozygous mutation carriers and families with CEP.
authors.affiliation: Department of Biotechnology, Kyoto Institute of Technology, Kyoto, Japan.
authors.forename: Dao Hoang
authors.initials: DH
authors.lastname: Thien Kim
authors.forename: Asako
authors.initials: A
authors.lastname: Kawazoe
authors.forename: Pham Dang
authors.initials: PD
authors.lastname: Bang
authors.forename: Nguyen Tien
authors.initials: NT
authors.lastname: Thanh
authors.forename: Shigeru
authors.initials: S
authors.lastname: Taketani
keywords: Congenital erythropoietic porphyria; Deficiency; Mutation; Photosensitivity; Uroporphyrinogen III cosynthase