Skewed X chromosome inactivation may be not associated with premature ovarian failure

Background.?In view of the controversies about the skewed X chromosome inactivation (XCI) and premature ovarian failure (POF) association, a meta-analysis of the published data was performed to evaluate the relationship between XCI skewing and POF.

Methods.?We searched for all published articles indexed in MEDLINE (1950～2009) and CNKI (1994～2009). Any case–control or cohort study that tested the association between skewed XCI and POF was included and data were extracted independently by two reviewers. We performed this meta-analysis involving 325 cases and 403 controls with Review Manager 4.2 software.

Results.?Four eligible studies were selected for meta-analysis. It suggested that there was no significant difference between the incidence of skewed XCI (XCI ≥70% skewing) in POF cases comparing to healthy controls, odds ratio (OR)?=?1.13 [95% confidence interval (CI): 0.84～1.53, P?=?0.42]. The link between extremely skewed XCI (XCI ≥90% skewing) and POF was also analysed, and no significant difference was found, either, OR?=?1.46 (95% CI: 0.79～2.69, P?=?0.22).

Conclusions.?Skewed XCI had no association with POF. However, more case–control and cohort studies are needed in the future.     

Association of extremely skewed X-chromosome inactivation with Taiwanese women presenting with recurrent pregnancy loss.

X-chromosome inactivation (XCI) is a phenomenon that occurs in female mammals. Typically, maternally and paternally-derived X chromosomes are inactivated at approximately the same frequency. If preferential inactivation occurs, the person is considered to have skewed XCI. Skewed XCI has been reported to occur more frequently in women who experience recurrent pregnancy loss (RPL). In this study, we sought to investigate if there is an association between skewed XCI and unexplained RPL in Taiwanese women. A total of 194 women who had experienced unexplained RPL were recruited into the study. Human androgen receptor or DXS6673E and DX15-134 loci were used in the XCI assay. The results of our study suggested that a cut-off point less than 90% may not be justified for skewed XCI. Only extremely skewed (more than 95%) XCI is associated with RPL. Extremely skewed XCI occurs in a subset of Taiwanese women with RPL.     

X-inactivation patterns in human embryonic and extra-embryonic tissues

Mice have skewed X chromosome inactivation (XCI) in extraembryonic tissue while examination of human placentae have yielded conflicting results. We investigated XCI patterns in human embryonic and extra-embryonic tissues. First and early second trimester placental and foetal tissues were collected. Cytotrophoblasts were isolated from the placentae. Female samples were identified and X-inactivation patterns were determined by analysis of androgen receptor (HAR) methylation patterns. Among 55 females heterozygous at the HAR, 37 had random and 18 skewed XCI. In foetal tissues a skewed XCI pattern was only observed in one liver and one intestine sample. A greater incidence of skewed XCI pattern was present in extra-embryonic compared to embryonic tissues (P=0.022). A markedly skewed XCI pattern was only found in one cytotrophoblast sample. Random and skewed XCI patterns were detected in human embryonic and extra-embryonic tissues. The extra-embryonic tissue had a higher proportion of skewed XCI, but marked skewed XCI was uncommon in both tissues. Skewed XCI may not play a role in normal human placentation.     

Pregnancy outcome in recurrent miscarriage patients with skewed X chromosome inactivation

OBJECTIVE: To analyze X inactivation in women with recurrent miscarriage to estimate whether skewed X inactivation is associated with recurrent miscarriage and whether it predicts next pregnancy outcomes. METHODS: A multicenter study was performed. A power calculation determined that 101 patients were needed to detect a difference in skewed X inactivation between patients and controls. Patients were entered into a prospective trial of mononuclear-cell immunotherapy and subsequently tested for skewed X inactivation. Age-matched controls had one live birth and no prior miscarriages. Results from our X inactivation assay were compared with those from an independent genetics laboratory. RESULTS: Greater than 75% skewing was seen in 22.6% of patients and 26.5% controls (P =.52). Greater than 90% skewing was seen in 6.6% of patients and 3.9% of controls (P =.77). There were 19.8% of primary aborters and 32% of secondary aborters with greater than 75% skewed X inactivation (P =.38). There were 4.9% of primary aborters and 12.0% of secondary aborters with greater than 90% skewed X inactivation (P =.27) Neither greater than 75% nor greater than 90% skewed X inactivation impacted next pregnancy outcomes (odds ratios = 0.87 [95% confidence interval (CI) 0.34, 2.3] and 1.4 [95% CI 0.27, 7.5], respectively). Results of the exchange of samples with an independent laboratory were highly correlated (alpha = 0.987, P <.001, coefficient of variation = 5.5%). CONCLUSION: Skewed X chromosome inactivation is not associated with recurrent miscarriage. A patient's X chromosome inactivation status does not predict next pregnancy outcome. Our assay correlates with another experienced laboratory.     

原因不明复发性流产患者母-胎界面T淋巴细胞受体β链可变区基因的表达水平和频率

目的 通过分析母-胎界面T淋巴细胞受体(TCR)β链可变区(BV)基因的表达水平和频率,探索T淋巴细胞参与原因不明复发性流产(RSA)发生的作用机制.方法 采集18例原因不明RSA患者(研究组)和4l例正常早孕人工流产妇女(对照组)的蜕膜组织,基因组扫描方法 检测两组患者蜕膜内TCR BV基因的表达,分析TCR BV基因表达水平和频率的分布与原因不明RSA的关系.结果 (1)研究组患者蜕膜组织中TCR BV基因的表达水平,BV19为0.029±0.031,高于对照组(0.013±0.010),而BV5.2的表达水平(0.040±0.035)低于对照组(0.067±0.052),两组间分别比较,差异均有统计学意义(P<0.05).其余各家族的表达水平两组间比较,差异均无统计学意义(P>0.05).(2)研究组TCR BV家族中表达频率最高的前4位为BV2、BV6、BV7和BV3,其表达频率分别为66.7%、66.7%、66.7%和61.1%,均超过了50%.研究组中,BV15、BV19和BV20的表达频率分别为33.3%、38.9%和33.3%,均高于对照组(分别为7.3%、14.6%和7.3%);BV4和BV7的表达频率分别为33.3%和66.7%,均低于对照组(分别为65.9%和92.7%),两组间分别比较,差异均有统计学意义(P<0.05).其余各家族的表达频率两组间比较,差异均无统计学意义(P>0.05).结论 原因不明RSA患者蜕膜组织内的TCR BV家族表达存在差异,表达频率变化显著的TCR BV家族可能导致免疫有关的流产发生的易感性.     

Skewed X inactivation and recurrent spontaneous abortion

Recent studies show that women experiencing recurrent spontaneous abortion exhibit nonrandom X-chromosome inactivation (XCI) more often than in controls. This suggests that genetic factors may be important in explaining the losses in this subset of women. Nonetheless there are a number of possible explanations for this finding and the underlying causes may be heterogeneous. One hypothesis commonly cited is that a mutation on the X chromosome results in both preferential inactivation of the mutated X as well as lethality of male embryos inheriting this mutated X. However, this hypothesis does not explain the increase in chromosome abnormalities observed in the karyotyped losses from women with recurrent pregnancy loss and skewed XCI. This finding leads us to suggest that the mechanism involved may be associated with a reduction in number of ovarian follicles, either due to X mutations affecting oocyte atresia or a restriction in precursor pool size during development.     

CAG repeat polymorphism of androgen receptor gene and X-chromosome inactivation in daughters of women with polycystic ovary syndrome (PCOS): relationship with endocrine and metabolic parameters

Background: The polycystic ovary syndrome (PCOS) is a hyperandrogenic disorder that arise from a combination of genetic and environmental factors. Aim: To assess the role of the androgen receptor (AR) CAG repeat polymorphism in the metabolic and reproductive features in daughters of women with PCOS (PCOSd). Methods: Sixty-seven PCOSd and 60 daughters of control women (Cd) were studied in early stages of sexual development. Sex steroids, glucose, insulin and lipids were determined. The AR CAG repeat sizes and X-chromosome inactivation (XCI) were analyzed. Results: PCOSd and Cd had similar mean number of CAG repeats and XCI pattern. In PCOSd and Cd, methylation-weighted biallelic means CAGn (mwCAGn) was not associated with androgen levels. In infants and pubertal PCOSd, mwCAGn was associated with a low concentration of HDL-cholesterol. Conclusions: AR CAG repeat polymorphism appears to be unrelated with serum androgen levels. However, the short mwCAGn variant may have a possible impact on the lipid profile in PCOSd.     

p53基因多态性与卵巢上皮性癌发病风险的关系

目的　探讨中国北方汉族妇女卵巢上皮性癌 (卵巢癌 )易感性与 p5 3基因第 4外显子的第 72密码子和第 3内含子多态性的关系。方法　应用序列特异性引物 ,以PCR技术检测 12 4例卵巢癌患者 (卵巢癌组 )和 12 8例健康妇女 (对照组 )的p5 3基因第 4外显子的第 72密码子和第 3内含子的基因型。结果　卵巢癌组和对照组脯氨酸 (Pro)、精氨酸 (Arg)等位基因频率分别为 5 3 2 %、4 6 8%和 4 6 1%、5 3 9%,两组比较 ,差异无显著性 (χ2 =2 5 6 3,P =0 10 9) ;卵巢癌组Pro/Pro、Pro /Arg、Arg/Arg 3种基因型频率分别为 2 9 0 %、4 8 4 %、2 2 6 %,与对照组 (2 1 1%、5 0 0 %、2 8 9%)相比 ,差异也无显著性 (χ2 =2 5 98,P =0 2 73) ;按病理类型分类 ,浆液性癌和宫内膜样癌两者间或分别与对照组间 ,其基因型频率与等位基因频率比较 ,差异均无显著性 (P >0 0 5 ) ;按手术病理分期分类 ,Ⅲ～Ⅳ期卵巢癌患者Arg等位基因及Arg/Arg基因型频率明显高于Ⅰ～Ⅱ期卵巢癌患者 (χ2 =7 4 94 ,P =0 0 0 6和 χ2 =8 318,P =0 0 0 4 )。卵巢癌组及对照组p5 3基因第 3内含子 16bp插入或缺序列 (PIN3)的A、A′等位基因频率分别为 94 8%、5 2 %及 94 5 %、5 5 %,两组比较 ,差异无显著性(χ2 =0 0 13,P =0 910 ) ;两组     

A novel X chromosome-linked genetic cause of recurrent spontaneous abortion

OBJECTIVE: Unexplained recurrent spontaneous abortion is a common women's health problem that affects approximately 1 of every 200 women who wish to have children. It has long been assumed that a large proportion of recurrent spontaneous abortion results from genetic problems, but no causative genes have been identified to date. Here, we tested the hypothesis that a subset of women with recurrent spontaneous abortion are carriers of X-linked recessive disorders that result in the loss of male pregnancies. STUDY DESIGN: X chromosome inactivation patterns, an assay used to detect women who are likely to be carriers of X-linked recessive cell-lethal traits, were compared between 105 female patients with idiopathic recurrent pregnancy loss and 101 women (control subjects) with a single successful pregnancy and no history of pregnancy loss. Inheritance patterns and gender of offspring were studied in relevant subsets of participants. RESULTS: Female patients showed a highly statistically significant increase in the frequency of skewed X chromosome inactivation (90%; P < .0005). Female patients with highly skewed X chromosome inactivation showed a significant decrease in male children. Four of 6 families that were studied showed maternal inheritance of the skewed inactivation trait. CONCLUSION: We found the 14% of women with unexplained recurrent pregnancy loss show highly skewed X inactivation, which suggests that they are carriers of X-linked recessive lethal traits. Furthermore, the observed gender bias among women with highly skewed X inactivation suggests selective loss of male conceptions, which is consistent with an X chromosome-linked genetic defect that leads to cell death or growth disadvantage. Identification of such female carriers is important for the reproductive counseling and treatment of these women.     

不明原因重复性自然流产妇女配偶精子DNA完整性

目的:探讨精子DNA完整性与重复性自然流产(RSA)的关系。方法:85例不明原因RSA妇女配偶(RSA组)和50例已生育的成年健康男性(对照组)的精液,应用精子染色质扩散实验(SCD)检测精子DNA完整性。将RSA组根据1年后怀孕结果分为3个亚组:怀孕组(30例)、流产组(26例)、未孕组(29例)。结果:RSA妇女配偶DNA损伤精子的百分率(14.6±6.9)%与对照组的(12.9±3.8)%相比无统计学差异(P0.05)。DNA损伤精子百分率大于20%视为精子DNA完整性异常,则有17.6%的RSA患者配偶的精子DNA完整性异常,6%的正常生育男性精子DNA完整性异常,但差异无统计学意义(P0.05)。怀孕组、流产组、未孕组配偶的DNA损伤精子百分率分别为(12.4±5.3)%,(14.6±6.5)%和(16.8±8.1)%,未孕组与对照组比较,差异有统计学意义(P0.05),怀孕组、流产组与对照组比较,差异无统计学意义(P0.05)。结论:精子DNA完整性异常与RSA继发不育有关,有必要筛查RSA患者配偶的精子DNA完整性。     

ACL(+)复发性流产与亚甲基四氢叶酸还原酶C677T和A1298C位点突变关联的研究

目的:探讨亚甲基四氢叶酸还原酶基因(methylenetetrahydrofolate reductase,MTHFR)C677T和A1298C位点突变与抗心磷脂抗体(anticard iolipin antibody,ACL)阳性复发性流产是否相关。方法:采用聚合酶链式反应-限制性片断长度多态性方法,检测39例原因不明复发性流产和82例正常对照的亚甲基四氢叶酸还原酶基因C677T和A1298C位点突变。结果:MTHFR 677 3种基因型(CC、CT和TT)在ACL(+)流产组和对照组分布有统计学差异(P=0.045),进一步分析表明,677TT在患者组中表达频率显著增大(P=0.026),T等位基因频率在患者组中也显著增大(P=0.018),MTHFR1298相关3种基因型(AA、AC和CC)和A、C等位基因频率在2组中分布无差异,同时发现8种C677T/A1298C连锁基因型,但都与ACL(+)复发性流产无关。结论:ACL(+)复发性流产与MTHFR C677T突变有关,表明除自身抗体有关的获得性凝血途径以外,遗传性凝血因素在此种类型的流产发生中也起一定的作用。     

复发性流产患者血浆白细胞介素-37含量检测及其临床意义

目的:探讨复发性流产(RSA)患者血浆中白细胞介素-37(IL-37)的含量检测及其临床意义。方法:采用酶联免疫吸附试验(ELISA)检测30例RSA患者(RSA组)、30例正常妊娠者(NP组)和10例健康对照者(HC组)的血浆IL-37含量,同时检测RSA组和NP组血浆中β-人绒毛膜促性腺激素(β-hCG)和孕酮(P)的含量以及外周血免疫细胞含量。结果:①RSA组血浆IL-37含量明显高于NP和HC组(P<0.05),RSA组曲线下面积AUC值达到0.7967。②RSA患者血浆IL-37含量与血β-hCG含量呈负相关关系(R=-0.3858,P=0.0387),RSA患者血浆IL-37含量与P含量呈负相关关系(R=-0.3759,P=0.0407);NP组血浆IL-37含量与血β-hCG和P含量均无相关性(P>0.05)。③RSA患者血浆IL-37含量与外周单核细胞比例呈负相关(R=-0.4750,P=0.0080),而NP组血浆IL-37含量与外周单核细胞比例呈正相关(R=0.4782,P=0.0447),两组中IL-37血浆含量与淋巴细胞、中性粒细胞及白细胞均无相关性...     

血管内皮生长因子（VEGF）及其可溶性受体在早期复发性流产患者中的表达及临床意义

目的：探讨血管内皮生长因子（VEGF）及其可溶性受体（silt．1）与复发性流产（RSA）的相关性。方法：应用酶联免疫吸附试验（ELIsAl技术和免疫组织化学方法分别检测30例RSA患者血清和绒毛中VEGF及silt-1的表达情况,并以同期因非意愿妊娠要求行人工流产术的正常早孕妇-k-（n=30）为对照,比较VEGF及silt-1表达的临床意义。结果：RSA组血清VEGF（2637．50±2145．09ng／L）、silt—l蛋白（13796．67±ll917．08ng／L）表达水平均高于对照组（分别为982．67±675．47ng／L和3540．67±2989．80ng／L）（P〈O．051：RSA组绒毛组织vEGF和silt-1的表达阳性率（分别为76．7％和96．7％）均高于对照组（分别为50．0％和66．7％）（P〈O．05）。结论：RSA患者血清和绒毛中VEGF、silt-1表达程度升高,可能是导致孕早期胚胎停育的原因之一。     

反复自然流产夫妇HLA-Cw等位基因多态性分析

目的:探讨免疫遗传因素在反复自然流产(recurrent spontaneous abortion,RSA)发病中的作用。方法:采用序列特异性引物聚合酶链反应(PCR-SSP)法,分析80对RSA患者夫妇和75对正常夫妇HLA-Cw等位基因的多态性。结果:病例组和对照组间Cw01-08各个等位基因阳性率均无统计学差异,但RSA组中夫妇双方均检测到Cw第Ⅱ组等位基因(Cw分子α重链上第80位为赖氨酸)者显著少于对照组,而RSA组中夫妇双方均未检测到Cw第Ⅱ组等位基因者显著多于对照因缺失可能与早期反复自然流产的发病有关。组,差异有统计学意义(P=0.013)。结论:RSA分子α重链上第80位为赖氨酸的HLA-Cw等位基     

Hysteroscopic findings in 344 women with recurrent spontaneous abortion

STUDY OBJECTIVE: To evaluate the prevalence of different anatomic factors in women with recurrent spontaneous abortion (RSA). DESIGN: Retrospective analysis over 9 years (Canadian Task Force classification II-2). SETTING: University hospital-affiliated endoscopic unit. PATIENTS: Three hundred forty-four consecutive patients with RSA and 922 controls referred for abnormal uterine bleeding. INTERVENTION: Diagnostic hysteroscopy. MEASUREMENTS AND MAIN RESULTS: Major and minor uterine mullerian abnormalities (septate, unicornuate uteri) were found significantly more often in women with RSA than in controls (32% vs 6%, p <0.001). The frequency of acquired uterine anomalies (submucous myomas, polyps) was significantly higher in controls (32% vs 9%, p <0.001). No significant differences were observed between groups in frequency of adhesions (4% vs 2%). CONCLUSION: Major mullerian uterine abnormalities are associated with RSA, and minor uterine anomalies may be correlated with an increased risk of recurrent miscarriage.     

男性不育症患者外周血白细胞雄激素受体的改变及意义

目的：探讨男性不育与外周血白细胞雄激素受体表达的关系。方法：根据精液分析及睾丸活检病理检查结果,将67例男性不育症患者分成少精子症组(n=21)、弱精子症组(n=15)、阻塞性无精子症组(n=14)和非阻塞性无精子症组(n=17),采用放射配体结合分析法检测不育症患者外周血白细胞雄激素受体(AR),同时采用放射免疫法检测血清睾酮(T)和雌二醇(E_2)水平,并以22例正常生育男性为对照。结果：外周血白细胞AR含量少精子症组、弱精子症组、阻塞性无精子症组与对照组比,均无统计学差异(P＞0．05)；非阻塞性无精子症组(782±98)与对照组(913±104)相比,差异有统计学意义(P＜0．01)。男性不育症各组与对照组相比,E_2和T水平差异均无统计学意义(P＞0．05)；而男性不育症患者精子密度与白细胞AR含量呈正相关(r=0．233,P=0．010)。结论：一部分男子不育的发生、发展过程可能与AR表达下调有密切关系。     

Is adenovirus a fetal pathogen?

OBJECTIVES: The purpose of this study was to test the relationship between adenovirus genetic material in the amniotic fluid and adverse pregnancy outcome. STUDY DESIGN: This was a prospective, observational study of women who were referred in the second trimester of gestation for either genetic amniocentesis or evaluation of fetal malformation. A 2-mL aliquot of amniotic fluid was subjected to multiplex polymerase chain reaction for a panel of viruses that included adenovirus and human genome controls. Fetuses with an abnormal karyotype were excluded from analysis. RESULTS: The prevalence of adenovirus was similar in normal (39/652) and anomalous fetuses (23/364; chi(2) test, P=.376). There was significant seasonal variation in the prevalence in both normal and anomalous fetuses (chi(2) exact test, P<.001), but no significant difference between groups. The monthly proportion of patients who underwent amniocentesis remained constant throughout the year (mean, 8.3%; chi(2) test, P=.67). Central nervous system anomalies and echogenic liver foci were significantly more common among fetuses with positive amniotic fluid polymerase chain reaction results for adenovirus (P<.005, respectively). CONCLUSION: Adenovirus is found in a similar prevalence and seasonal variation in sonographically normal and abnormal pregnancies. Although a specific fetal presentation was not identified, echogenic liver lesions with or without hydrops and neural tube defects were significantly more common in the presence of adenovirus. The significance of these findings deserves further study.     

Oxidative stress-related gene polymorphism and the risk of preeclampsia

OBJECTIVE: The purpose of this study was to determine whether genetic variability in oxidative stress-related enzymes contributes to individual preeclampsia susceptibility differences. STUDY DESIGN: Polymorphisms in the cytochrome P450 (CYP)1A1 (MspI), CYP1A1(Ile/Val), glutathione S-transferase (GST)M1, GSTT1, myeloperoxidase (MPO), and manganese superoxide dismutase (MnSOD) genes were evaluated by polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism (RFLP) in 214 healthy controls with an uncomplicated obstetric history, and in 121 preeclampsia patients. Chi2 analyses were used to statistically evaluate differences. RESULTS: No significant differences in the CYP1A1(MspI) or CYP1A1(Ile/Val) genotypes were observed between the healthy controls and the preeclampsia patients (chi2 = 1.43, P = 0.49 versus chi2 = 1.54, P = 0.46). The GSTM1 homozygous null type and GSTT1 homozygous null type were no differences in the patients and controls (chi2 = 0.01, P = 0.92 versus chi(2) = 0.31, P = 0.57), and no significant differences in the polymorphisms of the MPO and MnSOD genotypes were found between the patients and controls (chi2 = 2.00, P = 0.37 versus chi2 = 0.07, P = 0.96). CONCLUSION: Polymorphisms in the oxidative stress-related genes (CYP1A1, GSTM1, GSTT1, MPO, MnSOD) do not seem to be risk factors for preeclampsia.     

复发性流产患者外周血T细胞亚群变化及相关转录因子的表达

目的:检测复发性流产患者外周血中Th1、Th2和Th17细胞的变化情况及相关转录因子T-bet、GATA-3和STAT-3mRNA的表达水平。方法:对30例复发性流产(RSA)非孕期患者和30例正常非孕(NNP)妇女抽取抗凝静脉血5ml,Ficoll分离外周血单个核细胞(PBMC),采用流式细胞术检测Th1、Th2和Th17细胞的比例,PBMC培养5小时后采用酶联免疫吸附法(ELISA)检测培养上清中IFN-γ、IL-4和IL-17的水平,同时检测T-bet、GATA-3和STAT-3mRNA的表达水平。结果:RSA患者Th1细胞的百分比和Th17细胞的百分比均高于NNP组(P<0.05),Th2细胞的百分比低于NNP组(P<0.05)。RSA组PBMC培养上清中IL-4水平低于NNP组(P<0.05),而IFN-γ和IL-17水平明显高于NNP组(P<0.05)。RSA患者GATA-3mRNA表达较NNP组减少(P<0.05),而T-bet和STAT-3mRNA明显高于NNP组(P<0.01)。结论:RSA患者PBMC合成IFN-γ和IL-17的水平明显增高,合成IL-4的水平明显降低,表明存在T细胞亚群的分化失衡状态。这种失衡状态可能受到相应的核转录因子T-bet、GATA-3和STAT-3的调控。