Novel sporadic and recurrent mutations in KRT5 and KRT14 genes in Polish epidermolysis bullosa simplex patients: further insights into epidemiology and genotype-phenotype correlation.

Epidermolysis bullosa simplex (EBS) is a hereditary genodermatosis characterised by trauma-induced intraepidermal blistering of the skin. EBS is mostly caused by mutations in the KRT5 and KRT14 genes. Disease severity partially depends on the affected keratin type and may be modulated by mutation type and location. The aim of our study was to identify the molecular defects in KRT5 and KRT14 in a cohort of 46 Polish and one Belarusian probands with clinical suspicion of EBS and to determine the genotype-phenotype correlation. The group of 47 patients with clinical recognition of EBS was enrolled in the study. We analysed all coding exons of KRT5 and KRT14 using Sanger sequencing. The pathogenic status of novel variants was evaluated using bioinformatical tools, control group analysis (DNA from 100 healthy population-matched subjects) and probands' parents testing. We identified mutations in 80 % of patients and found 29 different mutations, 11 of which were novel and six were found in more than one family. All novel mutations were ascertained as pathogenic. In the majority of cases, the most severe genotype was associated with mutations in highly conserved regions. In some cases, different inheritance mode and clinical significance, than previously reported by others, was observed. We report 11 novel variants and show novel genotype-phenotype correlations. Our data give further insight into the natural history of EBS molecular pathology, epidemiology and mutation origin.

Prostaglandin-endoperoxide synthase genes COX1 and COX2 - novel modifiers of disease severity in cystic fibrosis patients.

Cystic fibrosis (CF) is one of the most common autosomal recessive diseases among Caucasians caused by a mutation in the CFTR gene. However, the clinical outcome of CF pulmonary disease varies remarkably even in patients with the same CFTR genotype. This has led to a search for genetic modifiers located outside the CFTR gene. The aim of this study was to evaluate the effect of functional variants in prostaglandin-endoperoxide synthase genes (COX1 and COX2) on the severity of lung disease in CF patients. To the best of our knowledge, it is the first time when analysis of COX1 and COX2 as potential CF modifiers is provided. The study included 94 CF patients homozygous for F508del mutation of CFTR. To compare their clinical condition, several parameters were recorded, e.g. a unique clinical score: disease severity status (DSS). To analyse the effect of non-CFTR genetic polymorphisms on the clinical course of CF patients, the whole coding region of COX1 and selected COX2 polymorphisms were analysed. Statistical analysis of genotype-phenotype associations revealed a relationship between the heterozygosity status of identified polymorphisms and better lung function. These results mainly concern COX2 polymorphisms: -765G>C and 8473T>C. The COX1 and COX2 polymorphisms reducing COX protein levels had a positive effect on all analysed clinical parameters. This suggests an important role of these genes as protective modifiers of pulmonary disease in CF patients, due to inhibition of arachidonic acid conversion into prostaglandins, which probably reduces the inflammatory process.

Analysis of exocrine pancreatic function in cystic fibrosis: one mild CFTR mutation does not exclude pancreatic insufficiency.

BACKGROUND: Cystic fibrosis (CF) is the most common cause of exocrine pancreatic insufficiency in childhood. The aim of the present study is to evaluate the correlation between genotype and exocrine pancreatic insufficiency in CF patients. The special emphasis was put on the analysis of mild CFTR mutations. DESIGN: The study comprised 394 CF patients and 105 healthy subjects (HS). Elastase-1 concentrations were measured in all subjects. RESULTS: Severe pancreatic insufficiency was associated with the presence of two CFTR gene mutations (DeltaF508, N1303K, CFTR dele 2,3 (21kb), G542X, 1717-1G-A, R533X, W1282X, 621GT, 2183AAG, R560T, 2184insA and DeltaI507, G551D, 895T) and mild insufficiency with the presence of at least one mutation (R117H, 3171insC, A155P2, 138insL, 296 + 1G-A, E92GK, E217G, 2789 + 5G-A. 3849 + 1kbC-T/3849 + 1kbC-T) genotype resulted in high elastase-1-values. However, in case of patients with genotype DeltaF508/3849 + 10kbC-T, 1717-1GA/3849 + 10kbC-T as well as with DeltaF508/R334W, both high and low elastase-1 concentrations were found. Low E1 values were found in a patient with DeltaF508/R347P genotype. CONCLUSION: Patients who carry two 'severe' mutations develop pancreatic insufficiency, whereas those who carry at least one 'mild' usually remain pancreatic sufficient. However, the presence of one mild mutation does not exclude pancreatic insufficiency.

[Analysis of mutations in the CFTR gene in patients diagnosed with cystic fibrosis in Poland]. / Analiza mutacji w genie CFTR u pacjentów z rozpoznana mukowiscydoza w Polsce.

Polish CF patients were screened extensively for mutations in the CFTR gene. Screening data demonstrated a high heterogeneity of CFTR mutations in the Polish population. Total 30 different mutations were characterised in 24 exons or introns of the gene. Among them, six mutations have been reported for the first time and submitted to the CF Genetic Analysis Consortium. In addition, 15 different polymorphisms were found, including three new ones. The screening resulted in 9% increase of the detection rate of CFTR alleles in the tested population. Frequencies of two of the identified mutations (CFTRdele2,3 and 2184insA) are relatively high (2.6% and 1%, respectively) and justify their inclusion into routinely screened mutations in genetic testing of Polish CF population.

[Identification of mutation and polymorphic changes in the CFTR gene of patients with obstructive azoospermia]. / Identyfikacja mutacji i zmian polimorficznych w genie CFTR u pacjentów z azoospermia obstrukcyjna.

Obstructive azoospermia is one of the symptoms of congenital bilateral absence of the vas deferens (CBAVD)--disease which is suggested as primarily genital form of cystic fibrosis. CBAVD is a result of mutations and polymorphisms in CFTR gene. We studied 9 the most common mutations and identified 3 mutations (delta F508, R117H, G542X). The study showed that: 37.1% of CBAVD patients (13 out of 35 examined patients) carried mutations in a single or both copies of the gene. We also found the increased frequency of IVS8-5T allele in this group. No increased frequency of mutations in CFTR gene was found in group of men with incorrect spermatogenesis.