| Autor: |
Pessoa, Vera, Oliveira, Alexandra, Santos, Daniela, Mendonça, Joana, Machado, Miguel P., Ferrão, José, Vieira, Luís, Lopes, Pedro, Kislaya, Irina, Matias-Dias, Carlos, Barreto, Marta, Faustino, Paula |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
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| Popis: |
Iron-Refractory Iron-Deficiency Anemia (IRIDA) is a rare autosomal recessive hypochromic microcytic anemia derived from loss-of-function mutations in the TMPRSS6 gene, which encodes Matriptase-2, a negative regulator of hepcidin expression. IRIDA patients have high hepcidin levels that prevent iron absorption and recycling. Very few studies concerning this pathology have been carried out in the Portuguese population and its molecular basis is still largely unknown. In this study, we aimed to identify genetic variants in TMPRSS6 in a sample of the Portuguese population with a hematological phenotype suggestive of iron deficiency. In addition, we intended to evaluate the performance of NGS for genetic screening of this large gene. We studied 100 adults with anemia and/or microcytosis and/or hypochromia collected by the Portuguese National Health Examination Survey (INSEF). Other possible genetic causes for these abnormal phenotypes, namely α- and β-thalassemia, were discarded after HBA1, HBA2 and HBB genetic screening. The TMPRSS6 gene (18 coding regions, exon/intron boundaries and regulatory regions) was amplified in 3 long-PCR fragments that were screened by NGS using Nextera XT libraries in a MiSeq platform. The genetic variants found were validated by Sanger sequencing (transcript ENST00000676104.1). Several known variants were identified along with two unreported mutations, c.1585T>C (p.Cys529Arg) and c.1580T>G (p.Phe527Cys). These novel mutations were classified as pathogenic by in silico analyses through Polyphen2, SIFT, and Missense3D. Moreover, Phyre2 software was used to produce a 3D structure of the mutated proteins, based on alignments with known protein structures, as there is no 3D model for Matriptase-2 on online databases. The two novel mutations were found in heterozygosity, explaining the mild abnormal hematological phenotypes and serum iron biomarkers presented by both patients. Functional studies should be performed to validate these findings. Our results widened the spectrum of TMPRSS6 pathogenic variants underlying hereditary iron deficiency-related pathologies. In addition, NGS revealed to be an appropriate tool for TMPRSS6 genetic screening. Este trabalho é um sub-estudo do INSEF, desenvolvido no âmbito do Projeto Pré-definido do Programa Iniciativas em Saúde Pública, foi promovido pelo Instituto Nacional de Saúde Doutor Ricardo Jorge através do Departamento de Epidemiologia e beneficiou de apoio financeiro concedido pela Islândia, Liechtenstein e Noruega, através das EEA Grants N/A |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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