Genetic polymorphisms in glutathione S-transferase T1 affect the surgical outcome of varicocelectomies in infertile patients

Glutathione S-transferases （GSTs）, superoxide dismutase 2 （SOD2） and NAD（P）H：quinone oxidoreductase 1 （NQO1） are anti-oxidant enzyme genes. Polymorphisms of GSTs, SOD2 and NQO1 have been reported to influence individual susceptibility to various diseases. In an earlier study, we obtained preliminary findings that a subset of glutathione S-transferase 7：1 （GSTT1）-wt patients with varicocele may exhibit good response to varicocelectomy. In this study, we extended the earlier study to determine the distribution of genotype of each gene in the infertile population and to evaluate whether polymorphism of these genes affects the results of surgical treatment of varicocele. We analyzed 72 infertile varicocele patients, 202 infertile patients without varicocele and 101 male controls. Genotypes of GSTs were determined by polymerase chain reaction （PCR）. Genotyping of SOD2 and NQO1 was performed using the PCR-restriction fragment length polymorphism （PCR-RFLP） method. A significantly better response to varicocelectomy was found in patients with the GSTTI-wt genotype （63.2%） and NQO1-Ser/Ser genotype （80.0%） than in those with GSTTI-null genotype （35.3%） and NQO1-Pro/Pro or NQO1- Pro/Ser genotype （45.2%）, respectively. The frequencies of glutathione S-transferase M1/T1, SOD2 and NQO1 genotypes did not differ significantly among the varicocele patients, idiopathic infertile patients and male controls. GSTT1 genotype is associated with improvement of semen parameters after varicocelectomy. As the number of patients with NQO1-Ser/Ser genotype was not sufficient to reach definite conclusions, the association of NQO1 genotype with varicocelectomy requires further investigation.

Genetic polymorphism of glutathione S-transferase T1 gene and susceptibility to idiopathic azoospermia or oligospermia in northwestern China

Aim： To investigate the association of glutathione S-transferase T1 （GSTT1） gene polymorphism in patients with idiopathic azoospermia or oligospermia in the northwestern China population. Methods： In the case-control study, GSTT1 genotypes were identified by multiplex polymerase chain reaction （PCR） with peripheral blood DNA samples from 78 patients with idiopathic azoospermia, 103 patients with idiopathic oligospermia and 156 age-matched controls with normal sperm concentration and motility, according to the criteria adapted from World Health Organization guidelines. All of the patients and controls were from northwestern China. Results： There is a significant association between GSTT1 null genotype with idiopathic azoospermia risk （odds ratio [OR]： 2.36, 95% confidence interval [CI]： 1.33-4.20, P = 0.003） or idiopathic oligospermia risk （OR： 2.00, 95% CI： 1.17-3.27, P = 0.010）. Conclusion： GSTT1 null genotype is a predisposing risk factor for sporadic idiopathic azoospermia or oligospermia in northwestern China. （Asian J Androl 2008 Mar; 10： 266-270）

Genetic polymorphism and mRNA levels of cytochrome P450ⅡE1 and glutathione S-transferase P1 in patients with alcoholic liver disease in different nationalities

BACKGROUND:Alcohol abuse and dependence are major factors in the pathogenesis of alcoholic liver disease(ALD).Alcohol abuse is becoming an increasingly severe problem among the Han,Mongol,and Korean nationalities in northeast China.This study aimed to investigate the relationship between ALD and the genetic polymorphism and expression levels of two enzymes,cytochrome P450ⅡE1(CYPⅡE1)and glutathione S-transferase P1(GSTP1)in patients of three nationalities.METHODS:Peripheral blood was collected from 353 Chinese patients with ALD,300 alcohol dependent patients without liver disease(alcoholic),and 360 healthy controls.Each group included patients from the Han,Mongol and Korean nationalities.Real-time polymerase chain reaction(PCR)and PCR-restriction fragment length polymorphism(PCR-RFLP)were used.RESULTS:Regardless of nationality,patients who carried the rare CYPⅡE1 C2 and GSTP1 Val alleles were at higher risk of ALD.The frequency of C2 and Val in patients with ALD was respectively 50.00%and 26.98%in the Han,31.36%and 22.87%in the Mongol,and 45.87%and 22.02% in the Korean nationality.No significant differences were seen in the frequency of either C2 or Val alleles in ALD patients among the three nationalities.In each nationality,the frequency of both C2 and Val alleles was significantly higher in ALD compared to alcoholic and healthy controls.Except for nationality,the average mRNA levels of CYPⅡ E1 in ALD patients and healthy controls were 10.05%and 2.21%,respectively.The average mRNA levels of GSTP1 in ALD patients and healthy controls were 0.53%and 2.12%,respectively.The mRNA level of CYPⅡE1 was higher,and that of GSTP1 was lower in patients with ALD compared to the controls.CONCLUSIONS:Except for nationality,patients with ALD in this series tended to have a higher mRNA expression of CYPⅡE1 and to carry the C2 allele,and tended to have a lower mRNA expression of GSTP1 and to carry the Val allele.There is a causal relationship between the polymorphic alleles,which leads to different mRNA levels and the development of ALD.

Expression of multidrug resistance 1 gene and C3435T genetic polymorphism in peripheral blood of patients with intractable epilepsy

BACKGROUND： Increased expression of multidrug resistance 1 （MDR1） mRNA in peripheral blood of patients with intractable epilepsy is not due to epilepsy drugs, but epilepsy behavior. Monitoring MDR1 expression in peripheral blood is a target for MDR1 gene evaluation. OBJECTIVE： To investigate the influence of antiepileptic drugs and seizures on MDR expression in intractable epilepsy, and to analyze the genetic polymorphisms of C3435T in the MDRl gene. DESIGN, TIME AND SETTING： Factorial designs and comparative observations at the experimental center of the Affiliated Hospital of Qingdao Medical College, Qingdao University between October 2003 and October 2004. PARTICIPANTS： A total of 120 subjects were recruited from the epilepsy clinical department of the Affiliated Hospital of Qingdao Medical College. Four groups （n = 30） were classified according to statistical factorial design： intractable epilepsy, treatment response, no treatment, and normal control groups. METHODS： One-step semi-quantitative reverse-transcription polymerase chain reaction technology was used to test expressions of the MDR1 gene in 120 subjects. C3435T polymorphisms in intractable epilepsy group and normal control groups were analyzed by polymerase chain reaction-restriction fragment length polymorphism. MAIN OUTCOME MEASURES： Expression of MDR1 mRNA in the four groups, and C3435T genetic polymorphisms in intractable epilepsy and normal control groups. RESULTS： MDRl gene expression was increased in the intractable epilepsy group, due to the factor seizures, but not the antiepileptic drugs. However, the interaction between the two factors was not statistically significant. Of the 30 subjects in the intractable epilepsy group, the following genotypes were exhibited： 3 （10%） C/C genotype, 9 （30%） C/T genotype, and 18 （60%） T/T genotype at the site of C3435T, while 4 （13%）, 10 （33%）, and 16 （53%） subjects were determined to express these genotypes in the normal control group, respectively. C and T allele frequency were 25% and 75% in the intractable epilepsy group, and 30% and 70% in the normal control group, respectively. However, there was no statistical difference between the groups. CONCLUSION： Results demonstrated that seizures, not antiepileptic drugs, induced MDR1 gene expression in intractable epilepsy. Genetic polymorphisms of C3435T in the MDR1 gene did not contribute to the development of multidrug resistance in patients with intractable epilepsy.

Forecast of the Heterosis of Imported Meat Sheep by Genetic Polymorphism of Microsatellite DNA

Forecast of the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA was done in different sheep breeds. The gene frequency, the polymorphism information contents, the number of effective alleles, the heterozygosity, and the genetic distances were studied in four imported meat sheep and Small Tail Han sheep using five microsatellite loci. The crossing effects on the Small Tail Han sheep with four imported meat sheep were tested. The results indicate that there are genetic polymorphisms at five microsatellite loci in five sheep breeds. Five microsatellite loci can be used for genetic diversity evaluation in sheep breeds. The genetic variability of Dorset is the highest, and that of the Small Tail Han sheep is the lowest in the five sheep breeds. The order of heterosis from large to small in four imported meat sheep by the analysis of genetic relationship is White-Suffolk, Black-Suffolk, Dorset, and Texel. This accords with the testing results of actual heterosis. It is feasible to forecast the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA, which will have an important value for sheep breeding in the future.

Genetic Polymorphism of Milk Protein and Their Relationships with Milking Performances in Chinese Yak

The milk protein polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE)from 109 Maiwa and 100 Jiulong yaks, and the relationships among milk protein polymorphisms,milking traits and milk protein compositions were studied. The results showed thatβ-CN,κ-CN andα-La were monomorphic,αs1-CN andβ-Lg were polymorphic, the dominantgenes were αs1-CN D and β-Lg E,respectively. The frequencies of αs1-CN D were 0.8073and 0.6000 and β-Lg E were 0.9770 and 0.9700 in two populations respectively.The meanheterozygosities were 0.1021 and 0.1867 in two populations. No significant effects onmilking traits and milk protein compositions were observed except for αs1-CN locus onfat percentage in Jiulong yak.

Relationship between the acid-suppression efficacy of proton pump inhibitors and CYP2C19 genetic polymorphism in patients with peptic ulcer

Objective To investigate acid-suppression efficacy of proton pump inhibitors(PPIs) in relation to CYP2C19 genetic polymorphism on patients with peptic ulcer. Methods By an open, randomized and control trial, fifty nine patients with active peptic ulcer were randomly assigned to receive one of three PPIs on a single dose (20 mg of each drug): omeprazole group (n=19), rabeprazole group (n=20) and esomeprazole group (n=20). Intragastric pH was recorded 1 hour before and 24 hours after administration. CYP2C19 genotype was tested in all patients. Results The EMs/PMs ratio of each group was 16/3,17/3 and 17/3, respectively. The total time that intragastric pH>4, time percent pH>4 and median pH in PMs patients were significantly higher than those in EMs patients of omeprazole group (P<0.05). But all these differences were not found in rabeprazole group and esomeprazole group. The pH of nocturnal acid breakthrough(NAB) in both rabeprazole group and esomeprazole group was higher than that of omeprazole group, while there was no significant difference between rabeprazole group and esomeprazole group.Conclusion The acid-suppression efficacy of omeprazole is highly dependent on CYP2C19 genetic polymorphism, while CYP2C19 genetic polymorphism may have a little influence on the acid-suppression efficacy of rabeprazole and esomeprazole. The acid-suppression action of rabeprazole and esomeprazole is superior to omeprazole, especially on night acid secretion.

Lack of Association between Genetic Polymorphisms Affecting Autonomic Activity and Coronary Artery Spasm

Coronary artery spasm （CAS） is one of the leading pathological causes of a wide spectrum of ischemic heart diseases, ranging from variant angina pectoris to acute myocardial infarction and even sudden cardiac death[1]. Furthermore, Pierron et al. concluded that CAS of angiographically normal or sub-normal arteries is responsible for death or myocardial infarction in 11.6% of all cases. Oddly, the incidence of CAS is remarkably higher in Asians than in Caucasians[3], suggesting genetic involvement In its pathogenesis.

ANALYSIS ON GENETIC POLYMORPHISM OF 6 STR LOCI ON CHROMOSOME 12 IN CHINESE HAN POPULATION

Objective To analyze the genetic polymorphism of 6 STR loci (D12S358, D12S1675, D12S1663, D12S1697, D12S1725 and D12S1613) on chromosome 12 in Chinese Han population. Methods EDTA-blood specimens were collected from 153 unrelated individuals of Chinese Han population in Shaanxi province. Allele and genotype frequencies for the 6 STR loci were estimated and statistical parameters of polymorphism were calculated. Results 8 alleles and 18 genotypes, 10 alleles and 17 genotypes, 9 alleles and 15 genotypes, 12alleles and 29 genotypes, 12 alleles and 31 genotypes, 8 alleles and 11 genotypes were observed at D12S358, D12S1675, D12S1663, D12S1697, D12S1725 and D12S1613, respectively. No deviations of the observed allele frequency from Hardy-weinberg equilibrium expectations were found for any of these loci. The Heterozygotes of these 6 loci were 78.89%, 66.10%, 54.95%, 79.10%, 71.98% and 59.48%, respectively. It indicated the high genetic polymorphism of the loci in Chinese Han population. Conclusion The 6 STR loci belonged to the genetic marker system of high discriminutesation and high information in Chinese Han population and can be used in the study of gene-related diseases.

RESEARCH OF GENETIC POLYMORPHISM OF 5-HTT IN CHILDHOOD AUTISM

Objective To reveal the relationship between the 5-HTTLPR and the Chinese Han nationality children with CA, compared the distribution of the 5-HTTLPR between the Han Chinese children with CA and healthy Han Chinese children ,and analyzed the association between the 5-HTTLPR and clinical symptoms of the Han Chinese children with CA. Methods Genomic DNAs of fifty subjects including 25 autistic children and 25 controls were extracted from blood samples. PCR amplification using Oligonucleotide primers flanking 5-HTTLPR was performed. Results ① Three kinds of alleles including the S (short) allele, the L (long) allele and the VL allele were found , and the 5-HTTLPR genotypes shown were S/S, L/L, S/L and L/VL. ② Allele frequencies did not differ significantly in patient groups in comparison with the control sample. No significant difference was identified between the observed 5-HTTLPR genotype distribution of the patient groups and control group. ③ The distribution of homozygous and heterozygous subjects between the two groups differed significantly. ④ The genotypes of the 5-HTTLPR polymorphism correlated significantly with the Body Movement Factor. ⑤ The allele frequency of healthy Han Chinese population and that of healthy Japanese population were similar. The frequency of S allele in not only autistic subjects but also healthy children in this study was considerably more than that in Caucasians and the frequency of L allele in our subjects decreased correspondingly. Conclusion ① A significant difference in the allele frequency between the Han Chinese and Caucasian populations was found. ② The genotypes of the 5-HTTLPR polymorphism correlated significantly with the Body Movement Factor of the patients. ③ The homozygote and the L allele were positively relevant to CA and they might be the risk factors of CA. The heterozygote and the S allele were negatively relevant to CA and they might be the protective factors of CA.

A Study of Genetic Polymorphism of Cassava Germplasms and ISSR Molecular Markers

[ Objective] This study aimed to analyze the genetic potymorphism of 39 cassava varieties （lines） preserved in Guangxi Zhuang Autonomous Region Research Institute for Subtropical Crops. [ Method ] ISSR primers with good polymorphisms and amplification effects in cassava were selected for PCR amplification of 39 cassava germplasms, statistics and analysis of the amplified bands were conducted. In addition, cluster analysis was conducted by using UPGMA method based on the genetic similarity among cassava varieties （lines）. [ Result] Ten pairs of ISSR primers were selected. A total of 70 clear electrophoretic bands were amplified, each pair of primers had amplified 3 -9 electrophoretic bands, with an average of 7, and the length of amplified bands ranged from 150 to 2,000 bp; cluster analysis showed that 39 cassava varieties （lines） were clustered into two categories by the similarity coefficient of 0.67 ; in addition, the genetic distance among cassava was very narrow, with genetic similarity coefficients ranging between 0.80 and 1.00. [ Conclusion] This study laid foundation for breeding of high- cmalitv cassava in China.

Genetic polymorphism of CYP2A6 is one of the potential factors determining tobacco-related cancer risk

While we studied pharmacokinetics of SM-12502 which was under development as an anti-PAF agent, we found three subjects showing a slow metabolic phenotype in its pharmacokinetics. Analyzing the genes for CYP2A6 from the three subjects, we discovered that the three subjects possessed the whole CYP2A6 gene deletion (CYP2A6*4C), a novel genetic polymorphism of the CYP2A6 gene. Genetically engineered Salmonella YG7108 cells expressing human CYP2A6 or CYP2E1 together with the NADPH-CYP reductase were established in our laboratory to compare the mutagen-producing capacity of these enzymes for various N-nitrosamines. We found that CYP2E1 was responsible for the metabolic activation of N-nitrosamines with relatively short alkyl chains, whereas CYP2A6 was involved in the metabolic activation of N-nitrosamines possessing relatively bulky alkyl chains such as a tobacco-specific nitrosamine, NNK, which has been known to cause lung tumor in rodents. Thus, to examine a hypothesis that individuals possessing the CYP2A6*4C have the reduced risk of lung cancer due to the lack of the capacity of the metabolic activation of certain carcinogens in tobacco smoke, a case-control study was performed.

Influence of organic anion transporting potypeptide(SLCO1B1 and SLCO1B3)genetic polymorphisms on mycophenolic acid in Chinese kidney transplantation patients

Objective To analyze the relationship between genetic polymorphisms of organic anion transporting polypeptide ( SLCO1B1 and SLCO1B3) and mycophenolic acid ( MPA) pharmacokinetics in Chinese kidney transplant recipients. Methods Gene mutations ( SLCO1B3 T334G,SLCO1B1 A338G) were detected in 68 recipi-

Genetic Polymorphism and Relationship Analyses of Standard Poodle and Bichon Frise Groups Based on 19 Short Tandem Repeat Loci

Context:As the increasing number of pet canines,the identification of canine has attracted much attentions in the forensic field,however,the genetic diversities of pet canines still remained unknown.Aims:To explore genetic polymorphisms of 19 short tandem repeat(STR)loci and genetic relationships between the two studied canine groups and reference group.Subjects and Methods:In the present study,genetic polymorphisms of 19 STR loci and a sex-linked zinc finger locus were analyzed in a total of 594 canines in Standard Poodle and Bichon Frise groups from China.Results:A total of 166,159 alleles were observed in the Standard Poodle,Bichon Frise groups with the corresponding allelic frequencies ranging from 0.0030-0.6108 to 0.0012-0.6148,respectively.The combined discrimination power and probability of exclusion of 19 STR loci in Standard Poodle and Bichon Frise groups were 0.9999999999999497,0.999962884;and 0.99999999999999995,0.999965955,respectively.Furthermore,the genetic distances between the two canine groups and Labrador retriever group were calculated,and the results indicated that Standard Poodle and Bichon Frise groups showed a closer genetic relationship,while the two canine groups had distant genetic relationships with Labrador retriever group.The result of population genetic structure revealed that genetic component distributions in the three canine groups were different.The predicted accuracies of the constructed random forest prediction model for three validation sets(25%individuals randomly selected from three populations with 808 individuals)were higher than 0.9,especially for the individuals in validation set from the Bichon Frise group is 1.Conclusions:The 19 STR loci could be used for individual identification,canine breed identification and paternity testing in the two canine groups.

Genetic polymorphisms of the renin-angiotensin-aldosterone system in Chinese patients with end-stage renal disease secondary to IgA nephropathy

Background Genetic variability in the renin-angiotensin-aldosterone system may modify renal responses to injury and disease progression. The angiotensin I-converting enzyme （ACE） gene insertion/deletion （I/D）, the angiotensinogen （AGT） gene, M235T, the aldosterone synthase （CYP11B2） gene, C-344T, and the angiotensin II type 1 receptor （AT1R） gene, Al166C, have been shown to be associated with IgA nephropathy （IgAN） and its progression. We determined the presence of these polymorphisms in 130 Chinese patients with IgAN, including 47 patients with end-stage renal disease （ESRD） and 120 healthy Chinese subjects, to assess their impact on the susceptibility to disease and the liability of progression to ESRD. Methods Genotyping was performed with DNA isolated from peripheral leucocytes using polymerase chain reaction amplification of the polymorphic sequence, restriction enzyme digestion, and separation and identification of DNA fragments. Clinical data from renal biopsies were collected. Results ACE, AGT, CYP and AT1R genotype distributions were similar in patients with IgAN and in controls. Comparing patients with ESRD （IgAN-ESRD） and those without ESRD （IgAN-non ESRD）, there was a significant increase only in the ACE DD genotype （P 〈0.05） among the four gene polymorphisms. There was significant dominance of the male （P 〈0.05）, more marked hypertension （P 〈0.01）, proteinuria （P 〈0.01） and increased serum creatinine during renal biopsy （P〈0.01） in the IgAN-ESRD group. Conclusion Among the ACE, AGT, ATIR and CYP gene polymorphisms, only the DD genotype may predispose the individual to increased risk of progression to ESRD in the Chinese population.

Genetic polymorphism in matrix metalloproteinase-9 and the susceptibility to chronic obstructive pulmonary disease in Han population of south China

Background There are many candidate genes for chronic obstructive pulmonary disease (COPD). Matrix metalloproteinase-9 (MMP-9) plays an essential role in tissue remodeling and repair associated with development of COPD. In this study we investigated the correlation between MMP-9 gene polymorphism and COPD susceptibility in the Han population of South China.Methods We examined the frequency of polymorphic genotypes of the MMP-9 promoter (-1562C/T) in 100 COPD patients and 98 healthy smokers by restriction fragment length polymorphism.Results The frequencies of polymorphic genotypes in promoters of MMP-9 were C/C 86%, C/T 14% in COPD group; and C/C 98%, C/T 2% in the control group. There were significant differences between the two groups (P<0.01). The allele frequencies were also significantly different between the COPD group and the control group (C allele frequency: 93% vs 99%, T allele frequency: 7% vs 1%, P<0.05 respectively).Conclusion The genetic polymorphism in promoters of MMP-9 gene is associated with the susceptibility to COPD in the Han population of South China.

Genetic polymorphisms of MC2R gene associated with responsiveness to adrenocorticotropic hormone therapy in infantile spasms

Background Infantile spasms is a severe epileptic encephalopathy, which is refractory to conventional antiepileptic drugs. Adrenocorticotropic hormone （ACTH） has been the major therapy for infantile spasms; however, ACTH therapy is ineffective for some patients. The variations in the receptor genes can contribute to antiepileptic drug resistance. This study was to elucidate the possible associations between the variations of the MC2R gene and ACTH responsiveness in patients with infantile spasms. Methods We screened for variations in the promoter and coding region of the MC2R gene in 91 Chinese patients with infantile spasms and 94 controls, using PCR and a direct sequencing method. The frequencies of the genotypes, alleles and reconstructed haplotypes were analyzed in the cases and controls. The association between ACTH responsiveness and genetic variations of the MC2R gene was also assessed. Results Four single nucleotide polymorphisms （SNPs） were identified in the MC2R promoter, one of which was a novel specimen at position-2 from the transcription start site ATT, -2T〉C. Three SNPs （rs1893220, rs2186944 and -2T〉C） showed a significant difference between the cases and controls （P 〈0.05 for all）. The frequency of the common TCCT haplotype carrying four-SNP major alleles was significantly lower in the cases （39%） than in the controls （60%） （P=-0.00003）. The homozygous carriers of the TCCT haplotype had a much lower relative risk than the non-carriers （RR=O.42, 95%C/ 0.26-0.70, P=-0.0001）. ACTH responsiveness was strongly associated with the TCCT haplotype （P=-0.000082）. Compared with non-carriers of the TCCT haplotype, the homozygous and heterozygous carriers were more responsive to ACTH therapy （P=0.0002; P=-0.0003, respectively）. Conclusions Our results indicated that the TCCT haplotype in the MC2R promoter is strongly associated with the responsiveness of the ACTH therapy performed on patients with infantile spasms. The polymorphisms of the MC2R promoter might be one important factor that influences the efficacy of ACTH therapy on infantile spasms.

Inflammatory Cytokines and Alzheimer's Disease: A Review from the Perspective of Genetic Polymorphisms

Neuroinflammatory processes are a central feature of Alzheimer＇s disease（AD） in which microglia are over-activated, resulting in the increased production of proinflammatory cytokines. Moreover, deficiencies in the antiinflammatory system may also contribute to neuroinflammation. Recently, advanced methods for the analysis of genetic polymorphisms have further supported the relationship between neuroinflammatory factors and AD risk because a series of polymorphisms in inflammation-related genes have been shown to be associated with AD. In this review, we summarize the polymorphisms of both pro- and anti-inflammatory cytokines related to AD, primarily interleukin-1（IL-1）, IL-6, tumor necrosis factor alpha, IL-4, IL-10, and transforming growth factor beta, as well as their functional activity in AD pathology. Exploration of the relationship between inflammatory cytokine polymorphisms and AD risk may facilitate our understanding of AD pathogenesis and contribute to improved treatment strategies.

Exploring the potential impact of nutritionally actionable genetic polymorphisms on idiopathic male infertility:a review of current evidence

Infertility affects about 15%of the world's population.In 40%-50%of infertile couples,a male factor underlies the problem,but in about 50%of these cases,the etiology of male infertility remains unexplained.Some clinical data show that lifestyle interventions may contribute to male reproductive health.Cessation of unhealthy habits is suggested for preserving male fertility;there is growing evidence that most preexisting comorbidities,such as obesity and metabolic syndrome,are highly likely to have an impact on male fertility.The analysis of genetic polymorphisms implicated in metabolic activity represents one of the most exciting areas in the study of genetic causes of male infertility.Although these polymorphisms are not directly connected with male infertility,they may have a role in specific conditions associated with it,that is,metabolic disorders and oxidative stress pathway genes that are potentially associated with an increased risk of male infertility due to DNA and cell membrane damage.Some studies have examined the impact of individual genetic differences and gene-diet interactions on male infertility,but their results have not been synthesized.We review the current research to identify genetic variants that could be tested to improve the chances of conceiving spontaneously through personalized diet and/or oral vitamin and mineral supplementation,by examining the science of genetic modifiers of dietary factors that affect nutritional status and male fertility.

Vitamin D Receptor(VDR) Genetic Polymorphisms Associated with Intervertebral Disc Degeneration

Intervertebral disc degeneration （IDD） is characterized by disc dehydration and herniation, which is often associated with low back pain and lumbar radiculopathy due to nerve root compression or inflammation. The pathophysiology of IDD is not completely elucidated so far. Some researchers have indicated that disc degeneration begins as early as the second decade of life （Mayer et al., 2013）. Common risk factors are considered to associate with age, gender, smoking history, occupation, disc injury, and biomechanical factors. However, some epidemiologic studies highlighted that disc degeneration may be caused to a large degree by hereditary factors with apparently a relatively minor effects of environmental and behavioral risk factors （Videman et al., 1998; Cheung et al., 2006; Eser et al., 2010; Mayer et al., 2013; Vieira et al., 2014）, which indicated that genetic factors might play an important role in the pathogenesis of IDD.