High prevalence of HFE gene mutations in patients with porphyria cutanea tarda in the Czech Republic.

BACKGROUND: Iron overload and hepatitis C virus (HCV) infection are independent factors which are thought to play a role in the pathogenesis of porphyria cutanea tarda (PCT). OBJECTIVES: To determine the prevalence of the HFE gene mutations p.Cys282Tyr (C282Y), p.His63Asp (H63D) and p.Ser65Cys (S65C), the p.Tyr250X (Y250X) mutation of the TFR2 gene, and HCV infection in patients with PCT in the Czech population, and to make comparison of the iron status among the respective genotypes. METHODS: Iron metabolism indices, results of mutational analysis and serological markers of HCV infection were examined in 63 patients with PCT. RESULTS: The HFE gene mutations were detected in 70% of patients with PCT compared with 35% in the control group (P < 0.001). Mean serum ferritin levels were increased in all genotypes, the highest being in homozygotes for the p.Cys282Tyr mutation. HCV infection was detected in only 8% of patients with PCT. CONCLUSIONS: There was a very high prevalence of the p.Cys282Tyr and p.His63Asp mutations observed in patients with PCT accompanied by mild degrees of iron overload, which was genotype dependent.

Lack of association of iron metabolism and Dupuytren's disease.

BACKGROUND: Iron accumulation as seen in genetic haemochromatosis is a major cause of hepatic fibrogenesis. A link between chronic liver disease and Dupuytren's disease (DD) is well established, especially in alcoholics. AIM: The aim of the present study was to test the hypothesis that iron accumulation might cause fibrosis of the palmar aponeurosis leading to DD. PATIENTS AND METHODS: We examined iron metabolism, mutations of the HFE gene, serum cholesterol, alcohol consumption, presence of chronic liver disease, diabetes and history of severe manual work in a group of 90 patients who had undergone surgery for a severe form of DD. The tissue removed during surgery was histologically examined to confirm the diagnosis of DD. For a control group, we used 33 healthy subjects with similar profiles. RESULTS: The DD group consisted of 82 men and 8 women. Chronic liver disease was found in 27% of DD patients, compared with 6.1% of control subjects (P = 0.013). A history of hand traumatization was present in 33% of DD patients vs. 15% of control subjects (P = 0.048). Excessive alcohol consumption was present in 35.5% of DD patients compared with 15.1% of controls (P = 0.029). None of the other tested parameters, including the prevalence of HFE gene mutations, showed a significant difference between the two groups. CONCLUSIONS: Iron accumulation does not play a major role in the pathogenesis of DD. However, sex, age, manual labour and alcohol consumption are risk factors for progression of DD. We observed a high incidence of chronic liver disease in patients with DD.

[Frequency view on genome changes testing]. / Frekvencní pohled na vysetrení odchylek genomu.

Laboratories dealing with human genome, both inherited and acquired changes, dispose with similar methods and technology. The spectrum of genetic tests is relatively broad and the number of mutations or variants tested differs substantially. Also the number of examinations carried out in individual laboratories varies. Data presented in the tables come from the year 2004 and indicate the number of examinations requested and number of positive results. Many laboratories mentioned in the registry CZDDNAL (http://www.uhkt.cz/lab_a_vysetreni/nr lab_dna_diag/dna_lab_db) perform the same tests but there is also a great number of tests carried out by only one laboratory. Reasons of the request, cost-effectiveness and clinical utility of genetic testing is being discussed.

S65C and other mutations in the haemochromatosis gene in the Czech population.

HFE-linked hereditary haemochromatosis is a common autosomal recessive disease among Caucasians. The primary pathogenetic mechanism is excessive absorption of iron, which is deposited in various organs with their subsequent damage. In 1996 the gene responsible for haemochromatosis was detected--the HFE gene and its major mutation C282Y. The discovery of further mutations followed. Two sites of point mutations in the HFE gene, C282Y and H63D, are associated with more than 80% of haemochromatosis cases. Another mutation-- S65C--was detected on 8% of chromosomes of haemochromatosis patients, which were negative for mutations C282Y or H63D. The objective of this study was to identify the allele frequency of S65C and other HFE mutations in the Czech population. DNA extracted from 481 randomly selected newborn screening cards (Guthrie cards) from all over the country was analysed by PCR-RFLP. No (0%) sample was identified as homozygous for S65C or C282Y mutation and 8 (1.67%) were homozygous for H63D mutation. Twelve (2.49%) samples were S65C heterozygous, 33 (6.86%) samples were C282Y heterozygous, and 128 (26.61%) were H63D heterozygous. Of these, 11 (2.29%) carried one copy of each mutation, i.e. were compound heterozygous. Two samples were S65C/H63D compound heterozygous and nine were C282Y/H63D compound heterozygous. Allele frequencies for S65C, C282Y, and H63D were 1.25% (95% CI, +/- 0.70), 3.43% (95% CI, +/- 1.15), and 14.97% (95% CI, +/- 2.25), respectively. The observed genotype frequency for S65C, C282Y, and H63D mutations in the Czech Republic agrees with those reported for other Central European populations.

[Mutations in the HFE gene in patients with rheumatic diseases]. / Mutace v genu HFE u osob s revmatickým postizením.

BACKGROUND: Hereditary hemochromatosis is one of the most common autosomal recessive diseases. Aim of the study. 1. To establish frequency of C282Y and H63D mutations in the HFE gene (the hemochromatosis gene) in general population of the Czech Republic and in patients with hemochromatosis. 2. To find out whether hemochromatosis in homo- or heterozygous state plays a role in the pathogenesis of rheumatic diseases. METHODS AND RESULTS: In 32 patients with hereditary hemochromatosis, in 84 patients with polymyositis or dermatomyositis, in 246 patients with juvenile idiopathic arthritis and in 481 persons of the control group the presence of HFE gene mutations was etablished. The HFE gene mutations were screened for by restriction enzyme analysis performed on PCR amplified products. In the control group, 6.86% carriers of the C282Y mutation and 26.61% those of H63D were found. Homozygous C282Y or H63D mutation was found in 90.6% (p<0.001) of patients with hemochromatosis. Heterozygous C282Y mutation was found in 12.2% (p<0.05) of patients with juvenile idiopathic arthritis. We didn't detected higher prevalence of HFE gene mutations in patients with polymyositis and dermatomyositis. CONCLUSIONS: Results of this study show that heterozygosity for C282Y mutation may be a risk factor for juvenile idiopathic arthritis but not for polymyositis and dermatomyositis.

The frequency of alleles of the Pro12Ala polymorphism in PPARgamma2 is different between healthy controls and patients with type 2 diabetes.

The aim of this initial case-control study was to determine the association between common Pro12Ala polymorphism in the PPARgamma2 gene and type 2 diabetes in the Czech Republic. Furthermore, the effect of this polymorphism on phenotypic characteristics and on levels of lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides) was studied. One hundred thirty-three patients with type 2 diabetes and 97 control subjects were investigated. PCR and RFLP analysis were used for identification of individual genotypes. In the group of patients, three samples (2.26%) were identified as homozygous for the Ala/Ala genotype and 99 samples (74.44%) were homozygotes for the Pro/Pro genotype. Thirty-one samples (23.31%) were identified as Pro12Ala heterozygous. In the control group, six samples (6.19%) were homozygous for the Ala/Ala genotype and 61 samples (62.89%) were homozygotes for the Pro/Pro genotype. Thirty samples (30.93%) were identified as Pro12Ala heterozygous. The allele frequency for the Ala allele was lower in the type 2 diabetic group than in the control group (13.91% vs. 21.43%, P = 0.022). There was no difference (at P < 0.05) between the phenotypic characteristics (BMI, sex) studied in the group of patients according to the Pro12Ala genotype. There was no significant effect of the Pro12Ala polymorphism on lipid levels.

[Significance and prevalence of the C282Y gene mutation of primary hemochromatosis in the pathogenesis of pophyria cutanea tarda]. / Význam a prevalence mutace C282Y genu primární hemochromatózy (HFE) v patogenezi pozdní kozní porfyrie (PCT).

BACKGROUND: Hitherto studies on the ethiopathogenesis of porphyria cutanea tarda (PCT) show that the major pathogenic factor is iron ion, which acts via inhibition of the uroporphyrinogen decarboxylase. New speculations have appeared on the possible relation of this role of iron and the occurrence of mutation of the recently discovered gene of the hereditary hemochromatosis HFE, which may cause the iron overloading of the organism. Our paper describes prevalence of the C282Y gene mutation (HFE) together with the clinical and laboratory record in PCT patients. METHODS AND RESULTS: PCT was diagnosed mostly on the basis of clinical finding of actinic-traumatic vesicular dermatitis and the typical laboratory record of elevated higher-carboxylic porphyrines in urine and stool. Other laboratory methods tested the liver functions, plasma iron level and its binding capacity, ferritine level. All patient underwent routine haematological testing. Presence of antibodies against hepatitis C was also assayed (Elisa test 2nd generation, Sanofi Pasteur). In patients with prominent laboratory alterations showing possibility of the hepatic structural lesion, histology from the liver punctate was done. Frequency data of the C282Y gene mutation (HFE) in PCT patients was estimated on the basis of the genetic testing using PCR reaction of our own system. Group of PCT patients had 69 persons (63 patients with the sporadic form and 6 patients with familiar form of the disease). Hereditary haemochromatosis C282Y gene mutation (HH) was found in 15 patients, three of them were homozygotes and twelve heterozygotes (three heterozygotes had the familiar form of the disease). Nobody in this group was positive in the HIV antibody testing. In all porphyria patients with the presence of mutated gene who underwent liver biopsy, siderosis of different degrees was identified. In three patients neither the phenotypic observation nor the laboratory testing have shown haemochromatosis. Prevalence of C282Y gene mutation HFE in patients with porphyria cutanea tarda was studied. Such mutation was found in 15 persons (12 heterozygotes and 3 homozygotes) from the group of 69 tested patients (21.7%). Such frequency is significantly higher than in the control--nonporphyric--persons (10%). Patients were without clinical symptoms. Laboratory haematological changes, typical for HH, manifested in some of them only (elevated level of ferritine was found in 10 from 15 porphyria patients, elevated sideremia in one of them). Red blood cell counts were in both homo- and heterozygotes normal. Concurrence of the two porphyrinogenic factors--presence of gene mutation HFE and hepatitis C infection--was not proved. Antibodies against hepatitis C virus were not identified in any of the patients. Siderosis was found to be only a symptomatic sign, which was pronounced in different degree in all 9 porphyria patients with C282Y gene mutation who underwent liver biopsy. CONCLUSIONS: Frequency of C282Y gene mutation in our patients with porphyria cutanea tarda appears similar to that in other Middle European countries. It differs significantly from the frequency found in South European and North European countries (British).