Background: About 10% of infertilities with obstructive azoospermia are congenital and caused by CF gene mutations. M469I mutation was observed for the first time in Taiwanese patients. This mutation not only causes CF, but also may be the origin of infertility too.Objective: In this study, we aimed in designing a rapid, reliable RFLP-PCR procedure for detection of M469I mutation. The correlation and association between M469I mutation with infertility was investigated in this study.Materials and Methods: one hundred ten patients (90 non obstructive and 20 obstructive) and 60 normal individuals were considered in this study. M469I mutation was detected using RFLP-PCR. This technique was completely designed for M469I genotyping, for the first time in our study. Amplification of the region surrounding the mutation in exon 10 of CFTR gene was then performed. RFLP analysis was carried out using the Nde I restriction enzyme.Results: All genomic DNA samples were genotyped successfully. M469I mutation was observed only in patients group. Therefore, genotype containing mutant allele (GT) has been detected only in the patients group. There was no significant correlation between GT and TT genotypes with infertility (p=0.437).Conclusion: The M469I mutation has only been observed in Exon 10 CFTR gene of infertile patients, not in the control group. This mutation causes congenital bilateral absence of vaz deferens and finally infertility. This indicates a strong association between the M469I mutation and male infertility. Therefore, this is a CF-causing CFTR mutation that could be considered as a cause of infertility.

A qualitative diagnosis of infertility requires attention to female and male physical abnormalities, endocrine anomalies and genetic conditions that interfere with reproduction. Many genes are likely to be involved in the complex process of reproduction. Cystic fibrosis (CF) incidence varies in different White people populations (a higher incidence of CF is observed in northern–western European populations than in southern European populations), and therefore the incidence of congenital bilateral absence of the vas deferens (CBAVD) may also vary in different White people populations. As CF is mainly observed in White people, hardly any data are available of CBAVD in non-White people, but frequent polymorphisms such as 5T are observed in most populations. The spectrum and distribution of cystic fibrosis trans membrane conductance regulator gene (CFTR) mutations differs between CBAVD and CF patients, and even compared with control individuals. Combinations of particular alleles at several polymorphic loci yield insufficient functional CFTR. The combination of the 5T allele in one copy of the CFTR gene with a cystic fibrosis mutation in the other copy is the most common cause of CBAVD in Iran.Because of techniques such as intracytoplasmic sperm injection (ICSI), CBAVD patients are now able to father children, however such couples have an increased risk of having a child with cystic fibrosis, and therefore genetic testing and counseling should be provided. Around 10% of obstructive azoospermia is congenital and is due to mutations the CF gene. This paper reviews the relationship of mutations in the CFTR gene with CBAVD.

Objective: The most common mutation in cystic fibrosis (CF), (Δ, F508-CFTR), results in impaired protein maturation, folding and transportation to the surface of the cell. As a consequence of impaired protein maturation and/or transport from the extracellular matrix to the cell, different systems are influenced, including gastrointestinal system and glandular system, reproductive system and respiratory systems. CF models are essential tools to provide further knowledge of CF pathophysiology. With this aim, we designed a transgenic CF model based on the homologous recombination (HR) system. Materials and Methods: In this experimental study, a specifically designed construct containing the CFTR gene with F508del was cloned into a PTZ57R cloning vector and then the construct was transformed into the male pronucleus by microinjection after in vitro fertilization (IVF). Then the rates of blastocyst formation and embryonic development at 72 hours after IVF, were evaluated using the inverted microscope and the insertion of the construct was approved by polymerase chain reaction (PCR) method. Results: The CFTR gene was successfully cloned into the PTZ57R cloning vector and overall, from 22 injected cells, 5 blastocysts were observed after pronuclear injection of the CFTR gene construct. PCR verification of the blastocyst with CFTR-specific primers represented complete recombination of CFTR into the mouse genome. Conclusion: For the first time we designed a unique genome construction that can be detected using a simple PCR method. The pronuclear injection was performed for the transformation of the genome construct into the male pronuclei using microinjection and the development of zygote to the blastocyst stage has been observed following transgenesis.

Cystic fibrosis (CF) is the most common inherited disorder in Caucasian populations, with over 1400 cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The type of mutations and their distributions varies widely between different countries and/or ethnic groups. Seventy Iranian cystic fibrosis patients were screened for the CFTR gene mutation using ARMS/PCR (amplification refractory mutation system) for the following mutations: ∆F508, N1303K, G542X, 1717-1G>A, R553X, W1282X, G551D, 621+1G>T, ∆I507 and R560T. Single strand conformation polymorphism (SSCP) analysis of exons 3, 7, 10, 11 and 17b, including both the exon/intron junctions, of the CFTR gene was performed in patients in whom no mutation could be identified on one or both CFTR genes. As a result of this screening, only three mutations were found: ∆F508 mutation was found in 25 (17.8%) alleles, N1303K in six (4.3%) alleles and G542X in five (3.6%) alleles. Thus, a total of 3 mutations cover 25.7% of CF alleles. These finding will be used for planning future screening and appropriate genetic counseling programs in Iranian CF patients.  

Background: Cystic fibrosis (CF) is a common autosomal recessive disorder that affects many body systems and is produced by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CF is also the most frequently inherited disorder in the West. The aim of this study was to detect the mutations in the CFTR gene in two Iranian families with CF.Methods: After DNA extraction using the salting out method, a mutation panel consisting of 35 common mutations was tested by PCR, followed by reverse hybridization Strip Assay. To confirm the mutations, we have also performed Sanger sequencing for all 27 exons, intronic flanking regions, and 5' and 3' UTRs of the CFTR gene.Results: Carrier testing in a spouse revealed a novel nonsense mutation in the CFTR gene (c.2777 T>A (p.L926X)) in exon 17 for husband and a previously described heterozygous splice site pathogenic mutation (c.1393-1G>A) in his wife. The other novel compound heterozygous missense mutation (c.3119 T>A (p.L1040H)), which was previously reported as nonsense c.3484C>T (p.R1162X) mutation, was found in exon 19 in patient screening.Conclusion: Two novel CFTR mutations in exons 17 and 19 are responsible for CF with severe phenotypes in two Iranian families. These two mutations supplement the mutation spectrum of CFTR and may contribute to a better understanding of CFTR protein function.