Introduction: Globally, infertility is estimated to be approximately 9-16% .Males are found to be solely responsible for 20-30% of infertility cases and contribute to 50% of cases overall.
Many causes and risk factors play a role in increasing the incidence of male infertility, which can be classified as congenital, acquired and idiopathic.The largest group of infertile men are those diagnosed as suffering from ‘idiopathic infertility’. These men constitute about a third of the patients attending infertility clinics .
Idiopathic male infertility is a multifactorial heterogeneous disease in which genetic causes can be identified in all major categories of male infertility.
In recent decades, we have been faced with a large decrease in sperm count and an increase in infertility in men all over the world. Without genetic diagnosis, doctors cannot give answers to couples about the causes of infertility, possible diseases, potential success of ART, etc.
With the advances in genomics, the number of genes related to male infertility has increased in recent years, and one of the candidate genes that has been recently studied and received attention is SRY-box transcription factor 5(SOX5).
Recent studies show that the SOX5 gene is related to male infertility and the high expression level of its short transcript (S-SOX5) in the testis shows that S-SOX5 plays an important role in regulating the expression of genes necessary for sperm function and can affect male fertility.
Considering the key role of S-SOX5 in the formation and function of sperm motile cilia and the specialized role in spermatogenesis within the testis and the regulatory role on the expression of key genes, polymorphism in this gene can affect the function of this gene and this Disorders may be associated with infertility in men.
Identifying the genetic changes in this gene can be helpful in diagnosing the cause of infertility.
Considering that no study has been conducted on the relationship between polymorphisms of this gene and idiopathic non-obstructive azoospermia infertility in men in Iran, in this research we concluded to Check the presence of the functional polymorphism of rs10842262, SOX5 gene in idiopathic non-obstructive azoospermia patients and compare with the control group of fertile men.
The desired polymorphism status of this gene was checked using the Modified ARMS-PCR method followed by Sanger sequencing in the available DNA samples and then subjected to statistical analysis.
Objective: To determine the relationship between SOX5 gene rs10842262 polymorphism and idiopathic non-obstructive azoospermia.
Methods: Methodology:
In this project, in the first stage, the files of azoospermia patients whose samples are available in the Royan DNA Bank were examined and among them the Infertile men who that met our criteria were selected. Then the extracted DNA of infertile patients with idiopathic non-obstructive azoospermia as well as the extracted DNA of fertile men (control group) were obtained from the DNA bank. Then, in the next step, according to the reported SNP (rs10842262) and the relevant clinical significance in this gene (SOX5), the primer was designed for this SNP and this region was amplified by PCR in both control and patient groups. In order to check the presence or absence of variants and check the sample type (heterozygous, healthy homozygous or diseased homozygous), the modified ARMS-PCR technique was used, which is a simple method to detect any mutation that includes base changes or small deletions. ARMS test is based on the use of specific PCR primers and allows DNA replication only when the target allele is present in the sample. Modified ARMS-PCR test is usually widely and accurately used to determine SNP (single nucleotide polymorphism) genotype with the help of special primers. Primer design for mutant (with SNP) and normal (without SNP) alleles allows the results to be easily analyzed after electrophoresis. Finally, a number of samples from each group were sequenced by Sanger method for further confirmation.In order to analyze the data and compare the frequency of genotypes and the frequency of alleles in the two studied groups, Chi – squared(X2 (test and SPSS software were used, and in all cases the error coefficient for reporting statistical differences was considered less than 0.05.
Results: Result:
The results of the statistical analysis showed that out of 102 healthy and fertile men, 29 people (28.4%) had the GG genotype, 12 people (11.8%) had the CC genotype, and 61 people (59.8%) had the CG genotype. Among the 94 infertile men with azoospermia Non-obstructive 29 people (30.9%) have GG genotype, 2 people (2.1%) have CC genotype and 63 people (67.0%) have CG genotype.
The results of statistical analysis showed that in the population of healthy and fertile men, the frequency of G allele is equal to 119 (58.3%) and the frequency of C allele is equal to 85 (41.7%).
In the population of infertile men with non-obstructive azoospermia, the frequency of G allele is 121 times (64.4%) and the frequency of C allele is 67 times (35.6%).
Conclusion: Conclusion:
According to the pvalue, the difference in the allelic frequency between the control group and the patient is not statistically significant because the P value is equal to 0.221, which is more than 0.05, but the difference in the genotypic frequency between the groups is statistically significant. P=0.032
Keywords: Infertility-Idiopathic- Non obstructive azoospermia-Polymorphism-SOX5