Molecular analysis of the SLC22A12 (URAT1) gene in patients with primary gout

OBJECTIVE: To analyse the SLC22A12 (URAT1) gene in primary gout patients, first-grade relatives and healthy controls and the possible association of them with demographic and clinical data. Subjects and METHODS: We included 69 consecutive patients with diagnosis of primary gout, as well as 29 first-grade relatives and 120 healthy volunteers. Demographic and clinical data were obtained from the patients and relatives. DNA was purified from peripheral blood and all 10 exons of the SLC22A12 (URAT1) gene were sequenced. RESULTS: We found six different mutations in the SLC22A12 gene in 16 out of 69 (23%) patients with primary gout. Five mutations were in exon 5 and one in exon 4; five out of six mutations were heterozygous (one compound heterozygous) and one homozygous. The C850G mutation (exon 5) was found in 11 gout patients, these patients have lower levels of triglycerides than the rest of the group: 160 +/- 56 vs 292 +/- 203 mg/dl (P = 0.038). In one family, we found SLC22A12 mutations in three relatives within exon 5. We did not find mutations in the other exons studied (1-3 and 6-10), nor in any of the 10 exons of the 120 healthy volunteers. CONCLUSIONS: We found several mutations in SLC22A12 gene associated with primary gout, the definite role of these mutations in URAT1 activity needs to be further studied.     

SLC22A4 and SLC22A5 gene polymorphisms and Crohn's disease in the Chinese Han population

OBJECTIVE: Recent genomic surveys have identified two single nucleotide polymorphisms (SNP) in SLC22A4 and SLC22A5 as susceptibility loci for Crohn's disease (CD). We conducted the present study to assess whether the two SNP and exon variants in SLC22A4 and SLC22A5 could be implicated in the vulnerability to CD of the Chinese Han population. METHODS: A total of 180 CD patients and 180 healthy controls were studied. Genotyping for the two positive sites and the SNP that we screened from all the exon regions in SLC22A4 and SLC22A5 were typed using the direct sequencing method. RESULTS: Neither individual SNP nor any haplotype was found to be associated with CD in our case‐control study. CONCLUSION: In contrast to the Caucasian population, SLC22A4 and SLC22A5 genes are unlikely to play a major role in susceptibility to CD in the Chinese Han population.     

广西壮族人群SLC2A9基因多态性位点与原发性痛风的关联性研究

［摘要］　目的　探讨广西壮族人群可溶性载体2家族成员9（SLC2A9）基因单核苷酸多态性（SNPs）与原发性痛风的关联性。方法　收集广西壮族人群246例原发性痛风患者和202名健康对照者的临床资料及血尿酸（UA）、空腹血糖、甘油三酯(TG)、总胆固醇（TC）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）、肌酐（Cr）、尿素氮（BUN）等实验室指标,比较两组临床及实验室指标的差异。Taqman-MGB探针法检测SLC2A9基因4个位点(rs10489070、rs734553、rs3733591、rs16890979)的基因型,比较两组基因型及等位基因分布频率。结果　痛风组的体质量指数（BMI）、TG、TC、LDL-C、Cr、UA水平显著高于对照组（P<0.05）。有痛风石的患者年龄更大,病程更长,累及关节数更多,肾结石发生率更高,TG、TC、LDL-C、Cr、UA水平更高,差异均有统计学意义（P<0.05）。rs10489070和rs3733591在痛风组与对照组基因型及等位基因分布频率差异有统计学意义（P<0.05）,携带C等位基因的个体发生痛风的OR值分别为1.413（95%CI：1.009～1.980）和1.739（95%CI：1.331～2.271）。rs3733591（CC）（aOR=2.113,95%CI：1.536～3.951）、rs10489070（CC）（aOR=1.981,95%CI：1.123～3.156）是痛风发生的独立危险因素。rs3733591（CC）（aOR=2.358,95%CI：1.114～3.221）、rs10489070（CC）（aOR=2.115,95%CI：1.689～4.547）是痛风石发生的独立危险因素。结论　我国壮族人群中,SLC2A9基因的rs10489070（CC）和rs3733591（CC）基因型是痛风和痛风石的独立危险因素,但目前易感位点影响痛风发病的具体机制尚不明确,下一步需要进行相关SNPs功能的研究。     

可溶性载体2家族成员9基因的单核苷酸多态性与我国川东北地区汉族人群原发性痛风发病的相关性研究

目的 探讨SLC2A9(rs10489070)的单核苷酸多态性与我国川东北地区汉族人群痛风发病及血尿酸水平的相关性.方法 采用Taqman(R)探针法检测痛风组(151例原发性痛风患者)和对照组(176名健康体检者)rs10489070(C＞G)位点基因型,分析基因型及等位基因在2组的分布频率,并比较不同基因型实验室指标及临床资料的差异.统计学处理采用t检验x2检验和(或)Fisher精确概率法.结果 rs10489070( C＞G)位点在所有研究对象的基因型分布均处于Hardy-Weinberg平衡.CC型在痛风组的分布频率显著高于对照组(78.8％和68.8％,P＜0.05),而CG型则低于对照组(19.9％和30.1％,P＜0.05);等位基因C和G在2组的分布差异无统计学意义(P＞0.05).有痛风石(14例)与无痛风石(97例)痛风患者基因型分布频率差异有统计学意义(P＜0 05),CG基因型在有痛风石者的分布频率显著低于无痛风石患者(0和22.7％,P＜0.05).携带CC基因型患者血尿酸及血糖水平均高于未携带CC基因型患者,但差异无统计学意义(P＞0.05).结论 SLC2A9 rs 10489070(C ＞G)的多态性可能与我国川东北地区汉族人群原发性痛风的易感性相关,携带CC基因型个体更易患痛风,CG基因型则可能对痛风的发病及痛风患者痛风石的形成具有保护作用.     

葡萄糖转运体9基因 rs3733591（C>T）的单核苷酸多态性与我国汉族人群原发性痛风发病的相关性研究

目的探讨葡萄糖转运体9（SLC2A9）基因 rs3733591（C>T）的单核苷酸多态性（SNPs）与我国汉族人群痛风发病及血尿酸水平的相关性,并分析其多态性与痛风患者、健康体检者 PBMCs SLC2A9 mRNA 表达的相关性。方法①采用 TaqMan?探针法检测痛风组（297例原发性痛风性关节炎患者）和健康对照组（211名健康体检者） rs3733591（C>T）位点的基因型,χ2检验比较2组基因型及等位基因分布频率,计算比值比（OR）及95%可信区间（95%CI）。②采用实时荧光定量-PCR（RT-qPCR）法检测46例间歇期痛风患者及40名健康对照组 PBMCs SLC2A9 mRNA 的表达水平,非参数检验比较各组变量间的差异,并分析与 rs3733591（C>T）多态性的相关性。结果 rs3733591（C>T）位点的 TT 基因型在痛风组的分布频率显著低于健康对照组（37.7%与48.3%,P=0.017）,携带 TT 基因型的个体罹患痛风的相对风险OR 为0.647（95%CI：0.452~0.925）。而等位基因 T 在痛风组中的分布频率为60.9%,显著低于健康对照组的69.2%（χ2=7.324,P=0.007）,携带等位基因 T 的个体罹患痛风的相对风险 OR 为0.695（95%CI：0.533~0.905）;等位基因 C 在痛风组中的分布频率为39.1%,显著高于健康对照组的30.8%（χ2=1.440,P<0.05）。痛风组中携带 TC 基因型个体的外周血单个核细胞 SLC2A9 mRNA 的表达水平显著高于携带 TT 基因型者,而痛风组及健康对照组携带其他基因型的个体 SLC2A9 mRNA 的表达差异无统计学意义（P>0.05）。有痛风石（30例）痛风患者与无痛风石（190例）痛风患者的基因型及等位基因分布频率差异无统计学意义（P>0.05）。结论本研究提示 SLC2A9基因 rs3733591（C>T）位点的多态性可能与我国汉族人群原发性痛风的易感性相关,而与痛风患者痛风石形成无关;等位基因 C 可能为痛风发病的风险因子,而 TT 基因型及 T 等位基因可能对痛风发病具有保护作用;其多态性可能通过影响 SLC2A9基因的转录表达水平来参与痛风的发病。     

Prevalence of SLC22A4, SLC22A5 and CARD15 gene mutations in Hungarian pediatric patients with Crohn＇s disease

AIM: To investigate the frequency of the common NOD2/CARD15 susceptibility variants and two functional polymorphisms of OCTN cation transporter genes in Hungarian pediatric patients with Crohn's disease (CD). METHODS: A cohort of 19 unrelated pediatric and 55 unrelated adult patients with Crohn's disease and 49 healthy controls were studied. Genotyping of the three common CD-associated CARD15 variants (Arg702Trp, Gly908Arg and 1007finsC changes) with the SLC22A4 1672C-->T, and SLC22A5 -207G-->C mutations was performed by direct sequencing of the specific regions of these genes. RESULTS: At least one CARD15 mutation was present in 52.6% of the children and in 34.5% of the adults compared to 14.3% in controls. Surprisingly, strongly different mutation profile was detected in the pediatric versus adult patients. While the G908R and 1007finsC variants were 18.4% and 21.1% in the pediatric group, they were 1.82% and 11.8% in the adults, and were 1.02% and 3.06% in the controls, respectively. The R702W allele was increased approximately two-fold in the adult subjects, while in the pediatric group it was only approximately 64% of the controls (9.09% in the adults, 2.63% in pediatric patients, and 4.08% in the controls). No accumulation of the OCTN variants was observed in any patient group versus the controls. CONCLUSION: The frequency of the NOD2/CARD15 susceptibility variants in the Hungarian pediatric CD population is high and the profile differs from the adult CD patients, whereas the results for SLC22A4 and SLC22A5 mutation screening do not confirm the assumption that the carriage of these genotypes means an obligatory susceptibility to CD.     

Carnitine transporter defect due to a novel mutation in the SLC22A5 gene presenting with peripheral neuropathy

The carnitine transporter defect (McKusick 212140) is an autosomal recessive disorder caused by mutations in the SLC22A5 gene, which encodes the high-affinity carnitine transporter OCTN2 (Wang et al 2001). Diagnosis is suspected when plasma carnitine levels are extremely low and secondary causes of carnitine loss are excluded. The disease can present with recurrent Reye-like episodes of hypoketotic hypoglycaemia or with cardiomyopathy associated with myopathy (Stanley et al 1991). Here we report novel clinical findings in a 3-year-old with primary carnitine deficiency.     

Screening of SLC25A13 mutation in the Thai population

AIM:To determine the prevalence of SLC25A13 mutations in the Thai population.METHODS:A total of 1537 subjects representing the Thai population were screened for a novel pathologic allele p.Met1?（c.2T>C）and six previously known common SLC25A13 mutations:[Ⅰ]（c.851₈54delGTAT）,[Ⅱ]（g.IVS11+1G>A）,[Ⅲ]（c.1638₁660dup）,[Ⅳ]（p.S225X）,[Ⅴ]（IVS13+1G>A）,and[XIX]（g.IVS16ins3kb）using a newly developed TaqMan and established HybProbe assay,respectively.Sanger sequencing was employed for specimens showing an aberrant peak to confirm the targeted mutation as well as the unknown aberrant peaks detected.Frequencies of the mutations identified were compared in each region.Carrier frequency and disease prevalence of citrin deficiency caused by SCL25A13 mutations were estimated.RESULTS:p.Met1?was identified in the heterozygous state in 85 individuals,giving a carrier frequency of1/18,which suggests possible selective advantage of this variant.The question of p.Met1?homozygote lethality remains unanswered which may serve as an explanation as to why this homozygote has yet to be identified in patients/controls even with high allele frequency.The p.Met1?mutation has rarely been studied in populations other than Thai and Chinese;therefore,may have been overlooked.Development of the TaqMan assay in the present study would allow a simple,rapid,and cost-effective method for mass screening.Heterozygous mutations:[XIX]and[Ⅰ]were identified in 17 individuals,giving a carrier rate of 1/90 and a calculated homozygote rate of 1/33000.Two novel variants,g.IVS11+17C>G and c.1311C>T,of unknown clinical significance were identified at low frequency.CONCLUSION:This study highlighted the current underestimation of citrin deficiency and suggests the possible selective advantage of the p.Met1?allele.     

Identification of DLG5 and SLC22A5 gene polymorphisms in Malaysian patients with Crohn's disease

OBJECTIVE: The aim of this study was to investigate the association of DLG5 and SLC22A5 gene polymorphisms with the onset of Crohn's disease (CD) in a Malaysian cohort. METHODS: Genomic DNA of 80 CD patients and 100 healthy unrelated control individuals was extracted and analyzed via polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) on DLG5 (4136 C/A), DLG5_e26 and SLC22A5 (‐207 G/C) genetic polymorphisms. Data obtained from the study were then subjected to statistical analysis to test for risk association. RESULTS: Significant associations of both DLG5 polymorphisms with the development of CD in the Malaysian patients were observed in this study. The homozygous C genotype of the DLG5 polymorphism was significantly related to CD patients (P = 0.0023, OR = 2.5320), while the homozygous A was significant in control individuals (P = 0.0224, OR = 0.4480). In DLG5_e26 polymorphisms, we found a significant distribution of the homozygous insA genotype in CD patients (P = 0.0006, OR = 2.8916), whereas the heterozygous insA/delA genotype was significant in controls (P = 0.0007, OR = 0.3487). We hypothesized that there might be a complex interaction of both alleles, which confered a protective effect against the onset of CD. However, we did not observe any significant correlation of SLC22A5 polymorphisms with this disease. CONCLUSIONS: In our study, both polymorphisms in the DLG5 gene were found to be associated with CD patients in Malaysia. Therefore, these loci can be potentially used as susceptibility markers in the Malaysian population.     

Prevalence of the DNA repair enzyme-NEIL1 gene mutation in patients with Type 2 diabetes in the Turkish population

In spite of the fact that an indirect relationship between NEIL1 gene and Type 2 diabetes has been demonstrated in animal model studies, there have been no human studies showing this relationship. In our study, we aimed to show the relationship between NEIL1 mutation and Type 2 diabetes in humans. The study group consisted 70 patients with Type 2 diabetes and the control group consisted of 50 healthy individuals. The mean age was 53±11 yr and 49±11 yr, respectively. Two NEIL1 mutations (2.9%) were detected in the patient group. There was A→G change (133A→G) at the 133. position of the 8th exon with 257 bp length in base sequencing. There was no mutation in the control group. We searched NEIL1 gene mutation for the first time in patients with Type 2 diabetes. This mutation was "silent" as it did not cause any amino acid change. The effects of these mutations on the etiopathogenesis of disease are not known. Although the lysine encoded by AAG was identical to the lysine encoded by AAA, it is not clear if they have functional differences due to the changing environmental conditions. NEIL1 gene mutation may have causative role in the development of Type 2 diabetes.     

A novel mutation in the SLC40A1 gene associated with reduced iron export in vitro

Ferroportin disease is an inherited disorder of iron metabolism and is caused by mutations in the ferroportin gene (SLC40A1). We present a patient with hyperferritinemia, iron overload in the liver with reticuloendothelial distribution and also in the spleen, and under treatment with erythropheresis. A molecular study of the genes involved in iron metabolism (HFE, HJV, HAMP, TFR2, SLC40A1) was undertaken. In vitro functional studies of the novel mutation found in the SLC40A1 gene was performed. The patient was heterozygous for a novel mutation, c.386T>C (p.L129P) in the SLC40A1 gene; some of his relatives were also heterozygous for this mutation. In vitro functional studies of the L129P mutation on ferroportin showed it impairs its capacity to export iron from cells but does not alter its sensitivity to hepcidin. These findings and the iron overload phenotype of the patient suggest that the novel mutation c.386T>C (p.L129P) in the SLC40A1 gene has incomplete penetrance and causes the classical form of ferroportin disease. Am. J. Hematol. 89:689–694, 2014. © 2014 Wiley Periodicals, Inc.     

A Japanese case with Nasu-Hakola disease of DAP12 gene mutation exhibiting precuneus hypoperfusion

A 38-year-old Japanese man with Nasu-Hakola disease (NHD) had repeated pathological fractures and frontal lobe symptoms which developed when he was 18 and 26 years old, respectively. Neuropsychological testing showed memory impairment, and in particular, visuo-spatial memory at the age of 35. Furthermore, single-photon emission computed tomography revealed precuneus hypoperfusion. The patient later suffered prolonged convulsive seizures, which left him in a persistent vegetative state. Genetic testing confirmed a heterozygous mutation in the DAP12 gene (a single-base deletion of 141 G in exon 3) specific to NHD. Precuneus dysfunction might contribute to characteristic memory impairment of NHD.