The c.−190 C>A transversion in promoter region of protamine1 gene as a genetic risk factor for idiopathic oligozoospermia

Sperm chromatin condensation: epigenetic mechanisms to compact the genome and spatiotemporal regulation from inside and outside the nucleus

Sperm chromatin condensation is a critical step in mammalian spermatogenesis to protect the paternal DNA from external damaging factors and to acquire fertility. During chromatin condensation, various events proceed in a chronological order, independently or in sequence, interacting with each other both inside and outside the nucleus to support the dramatic chromatin changes. Among these events, histone-protamine replacement, which is concomitant with acrosome biogenesis and cytoskeletal alteration, is the most critical step associated with nuclear elongation. Failures of not only intranuclear events but also extra-nuclear events severely affect sperm shape and chromatin state and are subsequently linked to infertility. This review focuses on nuclear and non-nuclear factors that affect sperm chromatin condensation and its effects, and further discusses the possible utility of sperm chromatin for clinical applications.

Genetic variations as molecular diagnostic factors for idiopathic male infertility: current knowledge and future perspectives

INTRODUCTION

Infertility is a major health problem, worldwide, which affects 10-15% of couples. About half a percent of infertility cases are related to male-related factors. Male infertility is a complex disease that is the result of various insults as lifestyle issues, genetics, and epigenetic factors. Idiopathic infertility is responsible for 30% of total cases. The genetic factors responsible for male infertility include chromosomal abnormalities, deletions of chromosome Y, and mutations and genetic variations of key genes.

AREAS COVERED

In this review article, we aim to narrate performed studies on polymorphisms of essential genes involved in male infertility including folate metabolizing genes, oxidative stress-related genes, inflammation, and cellular pathways related to spermatogenesis. Moreover, possible pathophysiologic mechanisms responsible for genetic polymorphisms are discussed.

EXPERT OPINION

Analysis and assessment of these genetic variations could help in screening, diagnosis, and treatment of idiopathic male infertility.

The effect of infertile semen on the mRNA-based body fluid identification

In the past decade, mRNA markers have been well demonstrated as promising molecular markers in forensic body fluid identification (BFI), and successfully used in wide applications. Several studies have assessed the performance of semen-specific mRNA markers in distinguishing semen from other common body fluids at the crime scene. Infertility has been reported as a global health problem that is affecting approximately 15% of couples worldwide. Therefore, it is important for forensic researchers to consider the impact of infertility on semen identification. This study aimed to explore the effect of semen from infertile men (hereinafter "infertile semen") on BFI and to identify semen-specific mRNAs that can efficiently and accurately distinguish normal and infertile semen samples from other body fluids. Results showed that the selected five mRNAs (KLK3, TGM4, SEMG1, PRM1, and PRM2) performed a significantly high semen specificity in normal semen. Moreover, KLK3 was slightly influenced by infertile semen samples with over 98% positive results in all semen samples. The accuracy to predict normal semen reached up to 96.6% using the discrimination function Y1 with KLK3 and PRM1. However, when the infertile semen samples were included in discrimination function (function Y2 with KLK3), the accuracy rate of semen identification (including the normal and infertile semen) was down to 89.5%. Besides, the sensitivity of multiplex assay could reach down to 50pg. Our results suggest that it is important to consider the presence of infertile semen when using mRNAs to identify semen samples, which would have a far-reaching impact in forensic identification.

Evaluation of the association between polymorphisms of PRM1 and PRM2 and the risk of male infertility: a systematic review, meta-analysis, and meta-regression

Studies have reported the genetic gives rise to male infertility. The aim of the present meta-analysis was to evaluate the association between PRM1 (rs737008 and rs2301365) and PRM2 (rs1646022 and rs2070923) polymorphisms and susceptibility to male infertility. The association between PRM1 and PRM2 polymorphisms and the risk of male infertility was evaluated using specific search terms in the Web of Science, Cochrane Library, PubMed, and Scopus databases without language restriction until January 28, 2020. The association was determined by odds ratio (OR) and 95% confidence interval (CI) on five genetic models using Review Manager 5.3 software. The funnel plot analysis and sensitivity analysis were done by the Comprehensive Meta-analysis 2.0 software. Out of 261 records retrieved from the databases, 17 studies were analyzed in the meta-analysis, including the four PRM polymorphisms. The pooled results as OR (P-value) showed 0.96 (0.44), 1.04 (0.70), 0.94 (0.51), 0.94 (0.48), and 1.03 (0.72) for PRM1 rs737008 polymorphism and 1.67 (0.0007), 1.73 (0.06), 1.50 (0.007), 1.56 (0.004), and 1.62 (0.33) for PRM1 rs2301365 polymorphism in allele, homozygous, heterozygous, recessive, and dominant models, respectively. Moreover, the pooled results as OR (P-value) showed 1.19 (0.004), 1.15 (0.26), 1.08 (0.70), 1.05 (0.76), and 0.98 (0.82) for PRM2 rs1646022 and 0.88 (0.04), 0.84 (0.10), 1.05 (0.81), 0.90 (0.24), and 0.80 (0.02) for PRM2 rs2070923 in allele, homozygous, heterozygous, recessive, and dominant models, respectively. The results showed PRM1 rs2301365 and PRM2 rs1646022 polymorphisms were associated with an elevated risk of male infertility and PRM2 rs2070923 polymorphism had a protective role in infertile men.

The c.-190 C>A transversion in promoter region of protamine 1 gene as a genetic risk factor in Egyptian men with idiopathic infertility

Protamines are considered the most important structure in the sperm nucleus, and they are proteins with a significantly large amount of amino acids carrying a positive charge, which allows the formation of the tight package of the genomic DNA in the spermatozoa. Many authors studied the abnormalities in the protamine 1 (PRM1) and/or protamine 2 (PRM2) genes and reported their possible association with male infertility. The chromosome 16 (16p13.2) carries these genes containing multiple undiscovered single nucleotide polymorphisms. The aim of the present study was to investigate the association of c.-190 C>A transversions that occur in PRM1 with idiopathic infertility in a sample of Egyptian men. It was a case-control study, and blood samples were collected from sixty male patients complaining of idiopathic infertility and forty healthy fertile males. The c.-190 C>A transversion in promotor region protamine 1 gene (rs2301365) was assessed by 5' nuclease assay, using Rotor-Gene Q real-time PCR system. The results of the present study revealed that CA and AA genotypes in PRM1 gene were associated significantly with low sperm concentration and decreased sperm motility (p = 0.001). Cases carrying A allele had a 6.05-fold increased risk for idiopathic infertility than cases carrying the C allele (OR: 6.05, 95% CI: 2.038-17.98 p statistically significant ≤0.05). Analysis of the results revealed that the c.-190 C>A transversion may be involved in the development of male infertility.

Methionine Synthase Reductase-A66G and -C524T Single Nucleotide Polymorphisms and Prostate Cancer: A Case-Control Trial

Purpose:

Some variations in the sequence of methionine synthase reductase (MTRR) gene can increase the risk of various cancers such as prostate cancer. The aim of this study was to investigate the association between prostate cancer and the MTRR A66G and C524T gene single nucleotide polymorphisms (SNPs) using an in silico analysis.

Methods:

In this case-control study, 218 Iranian men, including 108 men with prostate cancer and 110 prostate cancer-free men, were enrolled. The MTRR A66G and C524T genotyping was performed by PCR-RFLP. Some of the bioinformatics tools were employed for the evaluation of polymorphism on the molecular aspects of the MTRR.

Results:

With regard to the MTRR A66G polymorphism, the genotype AG (OR: 0.85, 95% CI: 0.47-1.54, p= 0.6014), genotype GG (OR: 0.89, 95% CI: 0.42-1.87, p= 0.7512), and allele G (OR: 0.92, 95% CI: 0.63-1.35, p= 0.6686) were not associated with prostate cancer risk. However, the data for C524T SNP showed that the genotype CT was associated with prostate cancer risk (OR: 1.92, 95% CI: 1.06-3.47, p= 0.0308). Further, carriers of the allele T (OR: 1.80, 95% CI: 1.04-3.13, p= 0.0358) were associated with high risk of prostate cancer. In addition, bioinformatics analysis revealed that C524T SNP could affect some molecular aspects of the protein structure, while having no effect on the mRNA structure.

Conclusion:

The MTRR C524T is a genetic risk factor for prostate cancer; however, the MTRR A66G is not suggested as a suitable biomarker for prostate cancer. To obtain more reliable results, further studies are recommended to use larger sample sizes and investigate the effects of environmental factors.

Analysis of PRM1 and PRM2 Polymorphisms in Iranian Infertile Men with Idiopathic Teratozoospermia

Single nucleotide polymorphisms (SNPs) in a number of genes involved in sperm maturation are considered as one of the main factors for male infertility. The aim of the present case-control study was to examine the association of SNPs in protamine1 (PRM1) and protamine2 (PRM2) genes with idiopathic teratozoospermia. In this case-control study, some SNPs in PRM1 (c.49 C>T, c.102 G>T and c.230A>C) and PRM2 (rs545828790, rs115686767, rs201933708, rs2070923 and rs1646022) were investigated in 30 idiopathic infertile men with teratozoospermia (case group) in comparison with 35 fertile men (controls). Genotyping of SNPs was undertaken using polymerase chain reaction (PCR)-direct sequencing. For PRM1, c.230A>C, as a synonymous polymorphism, was detected in both teratozoo- spermic men (heterozygous n=26, homozygous minor n=1) allele frequency C(48) A(52) and controls (heterozygous n=15, homozygous minor n=4). All cases and controls were genotyped for rs545828790 in PRM2, a missense poly- morphism, as well as rs115686767 and rs201933708, both of which synonymous variants. The findings showed an intronic variant in PRM2 (rs2070923) was also present in both groups. Also, rs1646022, a missense polymorphism, occurred in teratozoospermic men (heterozygous n=10, homozygous minor n=5) and controls (heterozygous n=13, homozygous minor n=2). However, there were no significant differences in SNPs of PRM1 and PRM2 between the two groups, however, for c.230A>C, the frequency of the CA genotype was significantly higher in infertile men with teratozoospermia (P=0.001). We demonstrate that PRM2 G398C and A473C polymorphisms were associated with the teratozoospermia and its genetic variation was in relation to semen quality, sperm apoptosis, and morphology in the Iranian population. This study is a preliminary study and presenting data as part of a future comprehensive study to clinically establish whether these gene polymorphisms are biomarkers for susceptibility to teratozoospermia.

Lipoprotein lipase gene polymorphisms as risk factors for stroke: a computational and meta-analysis

OBJECTIVES

Stroke is the most common neurological disorder and genetic susceptibility has an important role in its etiology. Polymorphism in several genes such as lipoprotein lipase (LPL) is propounded as a risk for stroke. This meta-analysis investigated the association of rs285 and rs320 LPL polymorphism with stroke risk.

MATERIALS AND METHODS

We searched PubMed, Clarivate Analytics Web of Science, Google Scholar, and Science Direct databases for appropriate studies. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of this association. Also, the effects of four common polymorphisms (rs268, rs285, rs320, and rs328) on the molecular aspects of LPL were evaluated by in silico tools. Five studies were included in meta-analysis after screening.

RESULTS

Our data indicated that rs320 significantly decreased the risk of stroke (G vs. T: OR= 0.64, 95%CI=0.54-0.76; GG vs. TT: OR=0.47, 95%CI=0.29-0.75; TG vs. TT: OR=0.65, 95%CI=0.53-0.80; TG+GG vs. TT: OR=0.62, 95%CI=0.51-0.75; GG vs. TT+TG: OR=0.51, 95%CI=0.32-0.82). Moreover, a significant association between rs285 and diminution of stroke risk was seen (P- vs. P+: OR=0.72, 95%CI=0.58-0.91; P-P- vs. P+P+: OR=0.50, 95%CI=0.31-0.82; P+P-+P-P- vs. P+P+: OR=0.72, 95%CI=0.53-0.96; P-P- vs. P+P++P+P-: OR=0.581, 95%CI=0.369-0.916). Also, the same results were observed after stratifying, without any publication bias (PEgger>0.05). Furthermore, computational analysis revealed that rs268 and rs328 may affect the protein structure (prediction: non-neutral; score=19; expected accuracy=59%) while rs320 could affect the RNA structure (distance=0.2264, P-value=0.0534; P<0.2 is significant).

CONCLUSION

This meta-analysis indicated that risk of stroke was decreased in rs320 and rs285 polymorphisms in the LPL gene.

IL-1ɑ C376A Transversion Variant and Risk of Idiopathic Male Infertility in Iranian Men: A Genetic Association Study

Background

IL-1α produced by Sertoli cells is considered to act as a growth factor for spermatogonia. In this study, we investigated the association of the C376A polymorphism in IL-1α with male infertility in men referring to the Kashan IVF Center.

Materials and Methods

In this case-control study, 2 ml of blood was collected from 230 fertile and 230 infertile men. After DNA extraction, the C376A variant was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, the molecular effects of the C376A transversion were analysed using bioinformatics tools.

Results

A significant association was observed between the homozygous genotype CC with male infertility [odds ratio (OR)=1.97, 95% confidence interval (CI)=1.14-3.41, P=0.016)]. Carriers of C (AC+CC) showed a similar risk for male infertility (OR=1.78, 95% CI=1.06-2.99, P=0.030). Also, allelic analysis showed that the C allele is associated with male infertility (OR=1.43, 95% CI=1.09-1.88, P=0.011). In sub-group analysis, we found that the AC genotype is associated with asthenozoospermia (OR=2.38, 95% CI=1.03-5.53, P=0.043). In addition, carriers of C were at high risk for asthenozoospermia (OR=2.25, 95% CI=1.01-4.10, P=0.047). Also, C allele was significantly associated with oligozoospermia (OR=1.44, 95% CI=1.01-2.06, P=0.049) and non-obstructive azoospermia (OR=1.67, 95% CI =1.04-2.68, P=0.034). Finally, in silico analysis showed that the C376A polymorphism could alter splicing especially in the acceptor site.

Conclusion

This is the preliminary report on the association of IL-1α C376A polymorphism with male infertility in the Kashan population. This association shows that the IL-1α gene may be a biomarker for male infertility, and therefore needs additional investigations in future studies to validate this.

Systematic review and meta-analysis of the genetic association between protamine polymorphism and male infertility

While several previous studies have proposed an association between male infertility and protamine polymorphism, the reported findings have shown some inconsistency. To evaluate the potential association between the two most common single nucleotide polymorphisms (rs2301365 and rs1646022) in protamine and male infertility, we performed a meta-analysis involving 2713 cases and 2086 controls from 15 published case-controlled studies. Overall, our analysis showed significant associations between the specific protamine single-nucleotide polymorphism (rs2301365) and male infertility, and this association was indicated by all of the models we tested. Subgroup analysis revealed significant associations with a Caucasian background, PCR sequence, population-based, case size of > 150 and case size of < 150 subgroups. Similarly, significant associations were found between rs1646022 and male infertility in the hospital population and case size of < 200 subgroups. However, trial sequential analysis showed that the number of patients in the study did not reach optimal information size. Further studies with larger sample sizes are now warranted to clarify the potential roles of the two protamine polymorphisms in the pathogenesis of male infertility. This may help us to understand the precise molecular mechanisms underlying the effect of protamines upon male infertility.

Association between two common transitions of H2BFWT gene and male infertility: a case-control, meta, and structural analysis

H2BFWT is one of the testis-specific histones that plays a fundamental role in spermatogenesis, and single nucleotide polymorphisms (SNPs) in this gene may result in male infertility. This study aimed to investigate the association between -9C>T and 368A>G transitions of H2BFWT gene and male infertility through a case-control, meta-analysis, and a bioinformatics approach. In this case-control study, 490 subjects including 240 idiopathic infertile men and 250 healthy controls were included. The -9C>T and 368A>G SNPs genotyping were performed by a PCR-RFLP method. To find eligible studies for meta-analysis, we searched valid scientific databases. The odds ratios with 95% confidence intervals were estimated to find the strength of these associations. Furthermore, the influences of two common transitions on the molecular features of H2BFWT were assessed by in silico tools. Our case-control data revealed that -9C>T is not associated with male infertility. But, there was a significant association between 368A>G and male infertility. In the meta-analysis, five eligible studies were included. Our data revealed significant associations between -9C>T, 368A>G, and male infertility in overall and stratified analyses. Moreover, structural analysis showed that 368A>G could affect the protein structure (SNAP prediction: non-neutral, score: 42, expected accuracy: 71%; SIFT prediction: deleterious, score: -2.55), while -9C>T may affect the binding nucleotide in the promoter region. Based on these findings, two aforementioned polymorphisms were associated with increased risk of male infertility. However, studies with larger sample size and different ethnicities are needed to obtain more accurate conclusions.

Aryl hydrocarbon receptor gene transitions (c.-742C>T; c.1661G>A) and idiopathic male infertility: a case-control study with in silico and meta-analysis

Aryl hydrocarbon receptor (AHR) is responsible for crucial events in male reproductive biology. Here, the association of the AHR transitions c.-742C>T and c.1661G>A with idiopathic male infertility was investigated in a case-control study, which is followed by a meta-analysis and a bioinformatic investigation. Blood and semen samples were obtained from a total of 135 idiopathic infertile men and 130 healthy controls. Participants were genotyped for the transitions using a PCR-RFLP method. A meta-analysis of five sets of data evaluated the association of c.1661G>A with male infertility, and using an in silico analysis, the possible molecular effects of the transitions predicted. Genotypes and alleles of AHR-c.-742C>T and c.1661G>A polymorphisms were not associated with the risk of male infertility significantly. However, the frequency of C/A haplotype was significantly associated with the increased risk of male infertility, and T/A haplotype was higher among controls significantly. Also, the frequencies of combined genotypes CT/GG, CT/GA and TT/GG were significantly associated with decreased risk of infertility. And, the meta-analysis showed that the AA versus GA/GG recessive model is associated with decreased risk of male infertility among the Iranian population. In silico analysis predicted that c.-742C>T does not alter the binding sites of the proposed transcription factors, but c.1661G>A poses a tolerable structural disturbance in AHR protein. In conclusion, these results showed that AHR c.-742C>T and c.1661G>A transitions separately could not be nominated as a risk or protective factor for male infertility. However, some combined models could affect infertility risk, especially among Iranian men.

The AhRR-c.565C>G transversion may increase total antioxidant capacity levels of the seminal plasma in infertile men

The Aryl hydrocarbon receptor (AhR)-repressor (AhRR) is a regulator of the AhR pathway, which plays an important role in xenobiotic and reactive oxygen species (ROS) metabolism. Total antioxidant capacity (TAC) is a major factor in semen quality that protects sperm against ROS stress. Malondialdehyde (MDA) is the indicator of lipid peroxidation damage that is occurred due to ROSs. In this study, we determined and compared the MDA and TAC levels of infertile men's semen and blood plasma regarding genotype groups of AhRR-c.565C>G transversion. Semen and blood samples of 123 infertile males were collected from the Fatemeh Zahra IVF Centre, Babol, Iran. TAC and MDA levels of seminal and blood plasma were measured by TBARS and FRAP methods, respectively. Cases were genotyped by the PCR-RFLP method. The frequency of c.565C>G genotypes was determined as CC (34.14%), CG (55.28%) and GG (10.58%). Mean levels of TAC μm/L and MDA nmol/mL in semen plasma of CC, CG and GG groups were (1365.7, 1.28), (1542.8, 1.51) and (1860.2, 0.82), respectively. Also, mean levels of TAC μm/L and MDA nmol/mL in blood plasma samples in CC, CG and GG genotypes were (806.14, 1.168), (727.1, 1.006) and (635.7, 0.83), respectively. Comparison of marker levels between genotypes revealed that the TAC level of semen plasma in the GG genotype was significantly higher than its level in the CC group (p < 0.05). Our findings showed that in seminal plasma of infertile men with the GG genotype of AhRR-c.565C>G transversion, the level of total antioxidant capacity is significantly higher in comparison with the CC genotype. Then, the G allele of AhRR-c.565C>G transversion may have a role in the increase in antioxidant capacity of seminal plasma.

Association of GSTO1 A140D and GSTO2 N142D Gene Variations with Breast Cancer Risk

Background:

Polymorphisms in glutathione S-transferase (GST) genes may contribute to breast cancer risk. The aim of this study was to investigate any association of two common GSTO1 A140D and GSTO2 N142D gene polymorphisms with breast cancer risk in an Iranian population followed by a protein structure analysis.

Materials and Methods:

In the case-control study, 303 subjects comprising 153 women with breast cancer and 150 healthy controls were included. Genotypes of GSTO1 A140D and GSTO2 N142D polymorphisms were assessed by PCR-RFLP. Bioinformatics tools were employed to evaluate the damaging effects of A140D and N142D on the structures of GSTO1 and GSTO2 proteins.

Results:

Our genetic association study revealed that the GSTO1 A140D polymorphism was associated with breast cancer in a dominant model (OR= 1.75, 95%CI= 1.07-2.86, p= 0.026). Also, the A allele was significantly associated with breast cancer risk (OR= 1.69, 95%CI= 1.09-2.60, p= 0.018). With regard to the N142D polymorphism, there were significant associations between the GG genotype (OR= 2.20, 95%CI= 1.14-4.27, p= 0.019) and the G allele (OR= 1.47, 95%CI= 1.06-2.05, p= 0.021) and risk of breast cancer. Structural analysis revealed that A140D and N142D polymorphisms cause changes in both primary and secondary structures of GSTO1 and GSTO2, respectively.

Conclusion:

Based on our results, GSTO1 A140D and GSTO2 N142D polymorphisms could be genetic risk factors for breast cancer, but further studies with larger sample sizes focusing on different ethnicities are needed to obtain more comprehensive results.

Association analysis of rs1049255 and rs4673 transitions in p22phox gene with coronary artery disease: A case-control study and a computational analysis

BACKGROUND

The p22phox gene encodes the main subunit of NADH/NADPH-oxidase. This enzyme is expressed in smooth muscle cells of arteries, and it produces the reactive oxygen species. On the other hand, oxidative stress plays a main role in the pathogenesis of coronary artery disease (CAD).

AIM

The aim of this study is to evaluate the association between rs4673 and rs1049255 polymorphisms of p22phox gene with CAD in an Iranian population which was followed with a computational analysis approach.

METHODS

In a cross-sectional study, we collected blood samples of 302 Iranian Caucasian including 143 patients and 159 healthy controls. Genotype of the polymorphisms was detected through PCR-RFLP method. A computational analysis was also performed using SNAP, Polyphen-2, Chou-Fasman, RNAsnp, and miRNA SNP databases.

RESULTS

Data of case control study demonstrated that CT genotype (R = 1.84, 95% CI = 1.13-3.00, p = 0.014) and T allele (OR = 1.53, 95% CI = 1.09-2.15, p = 0.013) of rs4673 polymorphism, have a significant association with enhanced risk of CAD. But rs1049255 analysis demonstrated the absence of such an association with CAD. Indeed, in silico data analysis demonstrated that rs4673 transition could impact on function of p22phox protein (SNAP score 56, expected accuracy 75%; Polyphen-2 score 0.99, sensitivity 0.09, specificity 0.99). Data derived from miRNA SNP database demonstrated that rs1049255 polymorphism increases the affinity of attachment between has-miR-3689a-3b with 3'-UTR of p22phox gene.

CONCLUSION

Our data demonstrated that rs4673 transition may be involved in susceptibility to CAD and could be applied as a potential biomarker for this disease.

Association of CCND1 Gene c.870G>A Polymorphism with Breast Cancer Risk: A Case-ControlStudy and a Meta-Analysis

Cyclin D1 (CCND1) plays an essential role in regulating the progress of the cell cycle from G1 to S phase. There is a common c.870G>A polymorphism in the CCND1 gene. The aim of this study was to investigate the association of CCND1 gene c.870G>A polymorphism with breast cancer risk in a case-control study, which followed by a meta-analysis and an in silico analysis. Three hundred and thirty-five subjects composed of 174 women with breast cancer and 161 healthy controls were included in the case-control study. CCND1 gene c.870G>A genotyping was performed by PCR-RFLP. Meta-analysis was done for 14 studies composed of 7281 cases and 6820 controls. Some bioinformatics tools were applied to investigate the effects of c.870G>A on the mRNA splicing and structure. Our data obtained from case-control study revealed that GA genotype (OR: 1.89, 95%CI: 1.12-3.17, p = 0.017), AA genotype (OR: 1.95, 95%CI: 1.08-3.53, p = 0.027), and A allele (OR: 1.44, 95%CI: 1.06-1.95, p = 0.019) were significantly associated with breast cancer risk. The results of meta-analysis showed a significant association between CCND1 c.870G>A polymorphism and breast cancer risk, especially in Caucasian population. In silico analysis revealed that c.870G>A transition affect CCND1 mRNA splicing and secondary structure.