title: Non-classical hereditary hemochromatosis in Portugal: novel mutations identified in iron metabolism-related genes.
abstract: The most frequent genotype associated with Hereditary hemochromatosis is the homozygosity for C282Y, a common HFE mutation. However, other mutations in HFE, transferrin receptor 2 (TFR2), hemojuvelin (HJV) and hepcidin (HAMP) genes, have also been reported in association with this pathology. A mutational analysis of these genes was carried out in 215 Portuguese iron-overloaded individuals previously characterized as non-C282Y or non-H63D homozygous and non-compound heterozygous. The aim was to determine the influence of these genes in the development of iron overload phenotypes in our population. Regarding HFE, some known mutations were found, as S65C and E277K. In addition, three novel missense mutations (L46W, D129N and Y230F) and one nonsense mutation (Y138X) were identified. In TFR2, besides the I238M polymorphism and the rare IVS5 -9T-->A mutation, a novel missense mutation was detected (F280L). Concerning HAMP, the deleterious mutation 5'UTR -25G-->A was found once, associated with Juvenile Hemochromatosis. In HJV, the A310G polymorphism, the novel E275E silent alteration and the novel putative splicing mutation (IVS2 +395C-->G) were identified. In conclusion, only a few number of mutations which can be linked to iron overload was found, revealing their modest contribution for the development of this phenotype in our population, and suggesting that their screening in routine diagnosis is not cost-effective.
authors.affiliation: Human Genetics Centre, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal.
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Mendes
authors.forename: Ana
authors.initials: A
authors.lastname: Ferro
authors.forename: Rute
authors.initials: R
authors.lastname: Martins
authors.forename: Isabel
authors.initials: I
authors.lastname: Picanço
authors.forename: Susana
authors.initials: S
authors.lastname: Gomes
authors.forename: Rute
authors.initials: R
authors.lastname: Cerqueira
authors.forename: Manuel
authors.initials: M
authors.lastname: Correia
authors.forename: António Robalo
authors.initials: AR
authors.lastname: Nunes
authors.forename: Jorge
authors.initials: J
authors.lastname: Esteves
authors.forename: Rita
authors.initials: R
authors.lastname: Fleming
authors.forename: Paula
authors.initials: P
authors.lastname: Faustino