Study of angiopoietin and plasminogen genes in hereditary angioedema.

OBJECTIVE: To investigate the presence of the Angiopoietin 1 (ANGPT1) and Plasminogen (PLG) mutations in patients with Hereditary Angioedema (HAE) and normal C1 esterase inhibitor (C1-INH) levels, who do not harbor the F12 gene mutation. METHODS: Patients clinically diagnosed with HAE but without C1-INH deficiency or dysfunction and F12 gene mutation were evaluated. DNA extraction, quantification, and dilution were performed at a concentration of 100 ng/µL, followed by a DNA amplification (PCR) for molecular evaluation of exon 2 of the ANGPT1 gene and exon 9 of the PLG gene for identification of mutations c.807G>T / p.A119S and c.988A>G / p.K330E, respectively. The PCR product was evaluated in 1% agarose gel electrophoresis. Sequencing was performed using the Sanger method. The electropherograms were analyzed using the FASTA® program. RESULTS: DNA samples from 15 women were sequenced. Their ages ranged from 10 to 60 years and the normal C1 esterase and C4 inhibitor serum levels ranged from 22 to 39 mg/dL and from 10 to 40 mg/dL, respectively. No mutations were detected in the analyzed exons of ANGPT1 and PLG. However, a single-nucleotide polymorphism (SNP) was detected in two homozygotic and five heterozygotic patients. CONCLUSION: Further studies are needed to evaluate these SNPs and scrutinize their potential for use as molecular markers of HAE and as novel therapeutic targets.

Study of angiopoietin and plasminogen genes in hereditary angioedema

SUMMARY OBJECTIVE To investigate the presence of the Angiopoietin 1 (ANGPT1) and Plasminogen (PLG) mutations in patients with Hereditary Angioedema (HAE) and normal C1 esterase inhibitor (C1-INH) levels, who do not harbor the F12 gene mutation. METHODS Patients clinically diagnosed with HAE but without C1-INH deficiency or dysfunction and F12 gene mutation were evaluated. DNA extraction, quantification, and dilution were performed at a concentration of 100 ng/µL, followed by a DNA amplification (PCR) for molecular evaluation of exon 2 of the ANGPT1 gene and exon 9 of the PLG gene for identification of mutations c.807G>T / p.A119S and c.988A>G / p.K330E, respectively. The PCR product was evaluated in 1% agarose gel electrophoresis. Sequencing was performed using the Sanger method. The electropherograms were analyzed using the FASTA® program. RESULTS DNA samples from 15 women were sequenced. Their ages ranged from 10 to 60 years and the normal C1 esterase and C4 inhibitor serum levels ranged from 22 to 39 mg/dL and from 10 to 40 mg/dL, respectively. No mutations were detected in the analyzed exons of ANGPT1 and PLG. However, a single-nucleotide polymorphism (SNP) was detected in two homozygotic and five heterozygotic patients. CONCLUSION Further studies are needed to evaluate these SNPs and scrutinize their potential for use as molecular markers of HAE and as novel therapeutic targets.

RESUMO OBJETIVO Investigar a presença das mutações no gene Angiopoietina (ANGPT1) e gene Plasminogênio (PLG) em pacientes com Angioedema Hereditário (AEH) com inibidor C1 esterase (C1-INH) normal e negativos para mutação do gene F12. MÉTODOS Foram avaliados pacientes com diagnóstico clínico de AEH sem deficiência ou disfunção de C1-INH e negativos para mutação do gene F12. Realizou-se extração, quantificação e diluição do DNA a uma concentração de 100 ng/uL, em seguida amplificação do DNA (PCR) para avaliação molecular do exon 2 do gene ANGPT1 e do exon 9 do gene PLG para identificação das mutações c.807G>T.p.A119S e c.988A>G p.K330E, respectivamente. O produto da PCR foi avaliado em eletroforese em gel de agarose 1%. Foi realizado o sequenciamento pelo método de Sanger. As análises dos eletroferogramas foram realizadas pelo programa FASTA®. RESULTADOS Foram sequenciadas amostras de 15 mulheres, idade entre 10 e 60 anos, com níveis séricos de inibidor de C1 esterase e C4 normais variando de 22 a 39mg/dL e 10 a 40mg/dL, respectivamente. Não foram identificadas mutações nos éxons analisados dos genes ANGPT1 e PLG. Entretanto no gene PLG foram encontrados polimorfismo de nucleotídeo único (SNP), em duas pacientes homozigotas e cinco heterozigotas. CONCLUSÃO Mais estudos sobre SNP são necessários para esclarecer estes achados pois eles podem ser utilizados como marcadores moleculares do AEH e alvo para novos tratamentos.

Comprehensive analysis of HFE gene in hereditary hemochromatosis and in diseases associated with acquired iron overload.

BACKGROUND: Patients with hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) may or not develop iron overload (IO), which is associated with worst prognosis, because can cause serious damage to organs. HFE gene controls the iron uptake from gut, particularly in patients with hereditary hemochromatosis (HH). AIM: To identify associations between HFE coding region in patients exhibiting hereditary hemochromatosis and in diseases associated with acquired IO. METHODS: We sequenced exons 2 to 5 and boundary introns of HFE gene, evaluating all polymorphic sites in patients presenting hereditary (hemochromatosis) or acquired iron overload HCV and HCC) and in healthy controls, using Sanger sequencing. We also determined the ensemble of extended haplotype in healthy control individuals, including several major histocompatibility complex loci, using sequence specific probes. Haplotype reconstruction was performed using the Arlequin and Phase softwares, and linkage disequilibrium (LD) between histocompatibility loci and HFE gene was performed using the Haploview software. RESULTS: The HFE*003 allele was overrepresented (f = 71%) and HFE*001 allele was underrepresented (f = 14%) in HH patients compared to all groups. A strong linkage disequilibrium was observed among the H63D-G, IVS2(+4)-C and C282Y-G gene variants, particularly in HH; however, the mutation IVS2(+4)T>C was not directly associated with HH susceptibility. The HFE*001/HFE*002 genotype conferred susceptibility to HCC in HCV patients exhibiting IO (P = 0.02, OR = 14.14). Although HFE is telomeric to other histocompatibility genes, the H63D-G/IVS2(+4)-C (P ≤ 0.00001/P ≤ 0.0057) combination was in LD with HLA-B*44 allele group in healthy controls. No LD was observed between HFE alleles and other major histocompatibility loci. CONCLUSION: A differential HFE association was observed for HH and for diseases associated with acquired IO (HCV, HCC). Since HFE is very distant from other histocompatibility loci, only weak associations were observed with these alleles.