LCT 13910 C/T polymorphism, serum calcium, and bone mineral density in postmenopausal women

Summary  LCT 13910 CC genotype is associated with lactose intolerance, a condition often resulting in reduced milk intake. Women with the CC genotype were found to have decreased serum calcium and reduced bone mineral density. Introduction  The CC genotype of the 13910 C/T polymorphism of the LCT gene is linked to lactose intolerance and low calcium intake. Methods  We studied 595 postmenopausal women, including 267 osteoporotic, 200 osteopenic, and 128 healthy subjects. Genotyping, osteodensitometry, and laboratory measurements were carried out. Results  Frequency of aversion to milk consumption was 20% for CC genotype and 10% for TT + TC genotypes (p = 0.03). The albumin-adjusted serum calcium was 2.325 ± 0.09 mmol/L for CC genotype and 2.360 ± 0.16 mmol/L for TT + TC genotypes (p = 0.031). Bone mineral density (BMD; Z score) was lower in the CC than TT + TC genotypes, respectively, at the radius (0.105 ± 1.42 vs 0.406 ± 1.32; p = 0.038), at the total hip (−0.471 ± 1.08 vs −0.170 ± 1.09; p = 0.041), and at the Ward’s triangle (−0.334 ± 0.87 vs −0.123 ± 0.82; p = 0.044). Conclusion  LCT 13910 C/T polymorphism is associated with decreased serum calcium level and lower BMD in postmenopausal women. Péter Lakatos and Gábor Speer contributed equally to this work.     

血管内皮生长因子基因多态性与糖尿病肾病的相关性研究

目的 探讨血管内皮生长因子(VEGF)-634G／C基因多态性与糖尿病肾病(DN)的关系。方法 运用PCR-限制性多态性片段长度(RFLP)技术检测98例健康对照者和216例2型糖尿病患者[其中DN患者104例，单纯2型糖尿病(DM)患者112例]的基因型，比较各组的基因型和等位基因频率。结果 (1)CC基因型者血清VEGFT水平高于CG及GG型者；(2)DN组CC基因型和C等位基因频率显著高于DM组和正常对照组；(3)与GG型和CG型组相比，CC型组DN的发生率明显上升；(4)Logistic回归分析显示VEGF、VEGF基因多态性、收缩压(SBP)、HbA1c、LDL-C、体重指数(BMI)是DN的危险因素。结论 VEGF-63gG／C多态性与2型DM伴发肾病的发生有关，C等位基因可能是DN的易感基因。     

A specific haplotype in the 3′ end of estrogen-receptor alpha gene is associated with low bone mineral density in premenopausal women and increased risk of postmenopausal osteoporosis

It is well established that the development of postmenopausal osteoporosis is under genetic influence. We have recently identified a synonymous single nucleotide polymorphism (SNP) in exon 8 of estrogen receptor- (ER) gene in the vicinity of the stop codon (G2014A) that is associated with an increased risk of postmenopausal osteoporosis. In the present study, we attempted to locate SNPs in the 3-unstranslated region (3UTR) of the ER gene that are in linkage disequilibrium with the exon 8 SNP and assessed their utilization in the risk assessment of postmenopausal osteoporosis in 352 Thai postmenopausal women. The association with bone mineral density (BMD) in premenopausal women was also investigated in 202 premenopausal women. A C to A SNP 1,748 nucleotides distal to the end of the stop codon (C3768A) was identified. The C3768A SNP was not overrepresented in subjects with osteoporosis. However, the presence of the A-C haplotype allele based on the A2014 and C3768 alleles was significantly related to the risk of osteoporosis independently of age, body weight, the G2014A and C3768A SNPs (odds ratio 2.36, 95% CI 1.42–3.91). Moreover, the presence of the A-C haplotype allele was associated with lower femoral neck BMD in premenopausal women ( P =0.05). We concluded that a specific haplotype in the 3 end of the ER gene is associated with lower BMD in premenopausal women and is associated with a higher risk of osteoporosis in postmenopausal women. It is likely that the haplotype allele exerts its influence on bone as early as during young adulthood to increase the risk of osteoporosis later in life.     

<Emphasis Type="Italic">LRP5</Emphasis> Polymorphisms and Response to Risedronate Treatment in Osteoporotic Men

Genetic factors are important in the pathogenesis of osteoporosis, but little is known about the genetic determinants of treatment response. Previous studies have shown that polymorphisms of the LRP5 gene are associated with bone mineral density (BMD), but the relationship between LRP5 polymorphisms and response to bisphosphonate treatment in osteoporosis has not been studied. In this study we investigated LRP5 polymorphisms in relation to treatment response in a group of 249 osteoporotic or osteopenic men who participated in a 24-month randomized double blind placebo-controlled trial of risedronate treatment. BMD and biochemical markers of bone turnover were measured at baseline and after 6, 12, and 24 months of follow-up. We analyzed two coding polymorphisms of LRP5, which have previously been associated with BMD, V667M (rs4988321) and A1330V (rs3736228), and found a significant association between the A1330V polymorphism and hip BMD at baseline. Subjects with the 1330 Val/Val genotype had 8.4% higher total-hip BMD compared with the other genotype groups (P = 0.009), and similar associations were observed at the femoral neck (P = 0.01) and trochanter (P = 0.002). There was no association between A1330V and spine BMD, however, or between the V667M polymorphism and BMD at any site. The difference in hip BMD between A1330V genotype groups remained significant throughout the study, but there was no evidence of a genotype–treatment interaction in either risedronate- or placebo-treated patients. In conclusion, the LRP5 A1330V polymorphism is associated with hip BMD in osteoporotic men, but allelic variations in LRP5 do not appear to be associated with response to bisphosphonate treatment.     

AANAT基因与青少年特发性脊柱侧凸的关联研究

目的 探讨人体内褪黑素合成通路与青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)发病之间的关系.方法 以单核苷酸多态性(SNP)位点为遗传标记,用测序法对性别(女性比率分别为77.67%和75.00%,P=0.648)和年龄[平均年龄分别为(15.18±2.15)岁和(15.58±2.50)岁,P=0.217]匹配的103例AIS患者和108例对照组进行基因分型筛查,对最小等位基冈频率(MAF)≥5%的位点结果 分别用SNPStats软件在线进行Hardy-Weinberg遗传平衡检验和单位点统计分析,用Unphased V3.07进行连锁不平衡(LD)检验和单倍体分析.结果 位于功能区的9个SNPs位点中只有rs28936679、rs4238989和rs3760138三个位点满足MAF≥5%,并满足Hardy-Weinberg遗传平衡检验;单位点分析结果 显示,5个Logistic回归分析模型检验的所有P值均＞0.05,提示这3个位点与AIS的发病无关;LD检验显示它们之间没有两个处在同一个单倍体块(D＞0.8)上,因而无法进行单倍体检验.结论 AANAT基因不是AIS的易感基因,我们需要对其他褪黑素合成相关的酶基因进行筛查研究.     

克罗恩病与肿瘤坏死因子超家族15基因的关系

目的 探讨中国人群中肿瘤坏死因子超家族15(TNFSF15)基因的多态性分布及其与克罗恩病(CD)的相关性.方法 飞行质谱法检测144例CD和500例正常对照者的TNFSF15基因多态性位点,分析基因多态性与CD发病及各临床表型的相关性.结果 在检测的5个SNF位点中,CD组和正常对照组间,有4个位点的基因型频率和等位基因频率存在差异,并且差异具有统计学意义(P<0.05).在构建的我国人群特有单倍型中,单倍型Haplotype 1在CD组中低于正常对照组(P<0.05),是CD的保护性单倍型.各CD临床表型与基因型见无明显相关(P>0.05).结论 TNFSF15基因的是我国CD的易感基因,在IBD的发病过程中具有重要作用.     

载脂蛋白E基因多态性在星形胶质细胞缺氧性损伤后早期凋亡中的作用

目的 探讨载脂蛋白E(apolipoprotein E,APOE)基因多态性在星形胶质细胞缺氧性损伤后早期凋亡中的作用.方法 原代培养APOE基因野生鼠、APOE转基因鼠(ε3、ε4)的星形胶质细胞,并纯化鉴定;利用缺氧法构建星形胶质细胞缺氧损伤模型,透射电镜观察细胞及线粒体形态变化,流式细胞仪检测细胞早期凋亡率及线粒体膜电位变化情况.结果 缺氧6h后,通过电镜观察到各组细胞足突肿胀,线粒体形态不规则、空泡化、嵴不规则,各组细胞之间形态变化无明显差异;APOEε4组细胞早期凋亡率、线粒体膜电位下降程度明显高于APOEε3组、APOE野生组(P＜0.05).结论 缺氧损伤后早期,与APOEε3组、APOE野生组比较,APOEε4组星形胶质细胞线粒体膜电位下降程度更大,这可能是导致更多的星形胶质细胞凋亡的原因之一.     

河北汉族人群 CYP1A2 C163A基因多态性研究

目的：探讨河北汉族人群细胞色素P4501A2（cytochrome P4501A2,CYP1A2）C163A基因多态性的分布情况。方法应用聚合酶链式反应－限制性酶切片段长度多态性（PCR‐RFLP）方法对210例河北汉族正常人进行CYP1A2 C163A基因多态性分析。结果河北汉族人群CYP1A2 C163A基因A和C等位基因的频率为：68．3％、31．7％。AA、AC、CC基因型频率分别为48．1％、40．5％、11．4％。符合 Hardy‐Weinberg 遗传平衡定律（χ2＝1．22,P＞0．05）,具有代表性。结论河北汉族人群CYP1A2基因存在C163A位点多态性。     

一例染色体复杂易位致胎儿多发畸形的遗传学诊断

目的: 对一例染色体复杂易位致多发畸形胎儿进行遗传学分析和诊断。方法: 对一例多发畸形胎儿行G显带染色体核型分析、单核苷酸多态性微阵列（SNP array）及荧光原位杂交（FISH）检测。胎儿父母行外周血染色体核型分析及FISH检测。结果: 胎儿的羊水染色体核型为46,XN,t（12;13）（q22;q32）。SNP array显示胎儿存在1q42.13q44重复（20 192 kb）及15q26.1q26.3缺失（13 293 kb）,核型分析与基因芯片结果不一致。FISH验证了SNP array的结果。母亲外周血FISH结果确认为隐匿性46,XX,t（1;15）（q42.1;q26.1）携带者,而胎儿遗传了其中一条衍生的15号染色体der（15）t（1;15）（q42.1;q26.1）。即胎儿遗传了父亲的t（12;13）（q22;q32）平衡易位及母亲的隐匿性平衡易位形成的衍生15号染色体。结论: 1q42.13q44重复和15q26.1q26.3缺失是导致本例胎儿畸形的遗传学病因,产前诊断时多种遗传学技术联合应用可为临床提供准确的诊断。     

Estrogen receptor α CA dinucleotide repeat polymorphism is associated with rate of bone loss in perimenopausal women and bone mineral density and risk of osteoporotic fractures in postmenopausal women

Summary The association between a newly identified CA repeat polymorphism of the estrogen receptor alpha gene (ESR1) with osteoporosis was investigated. Postmenopausal women with <18 CA repeats had low BMD, increased rate of bone loss and increased fracture risk. Introduction Studies have shown that intronic dinucleotide repeat polymorphisms in some genes are associated with disease risk by modulating mRNA splicing efficiency. D6S440 is a newly identified intronic CA repeat polymorphism located downstream of the 5’-splicing site of exon 5 of ESR1. Methods The associations of D6S440 with bone mineral density (BMD), rate of bone loss and fracture risk were evaluated in 452 pre-, 110 peri- and 622 postmenopausal southern Chinese women using regression models. Results Post- but not premenopausal women with less CA repeats had lower spine and hip BMD. The number of CA repeats was linearly related to hip BMD in postmenopausal women (β = 0.008; p = 0.004). Postmenopausal women with CA repeats <18 had higher risks of having osteoporosis (BMD T-score<−2.5 at the spine: OR 2.46, 95% CI 1.30–4.65; at the hip: OR 3.79(1.64–8.74)) and low trauma fractures (OR 2.31(1.29–4.14)) than those with ≥18 repeats. Perimenopausal women with <18 CA repeats had significantly greater bone loss in 18 months at the hip than those with ≥18 repeats (−1.96% vs. −1.61%, p = 0.029). Conclusions ESR1 CA repeat polymorphism is associated with BMD variation, rate of bone loss and fracture risk, and this may be a useful genetic marker for fracture risk assessment. Funding Source: This project is supported by CRCG Grant, Bone Health Fund, Matching Grant and Osteoporosis and Endocrine Research Fund of the University of Hong Kong.