Linlin Cui

Genotype–phenotype correlations of PCOS susceptibility SNPs identified by GWAS in a large cohort of Han Chinese women

STUDY QUESTION Are there any correlations between the phenotypes of polycystic ovary syndrome (PCOS) and the genotypes of the PCOS susceptibility single nucleotide polymorphisms (SNPs) in THADA, DENND1A and LHCGR? SUMMARY ANSWER The PCOS susceptibility genes, THADA and DENND1A, carry risk alleles that are associated with endocrine and metabolic disturbances in patients with PCOS. WHAT IS KNOWN ALREADY PCOS is a heterogeneous endocrinopathy characterized by oligo-anovulation, hyperandrogenism and polycystic ovaries. In a previous genome-wide association study, the SNP variants rs13429458, rs12478601, rs2479106, rs10818854 and rs13405728 in the THADA, DENND1A and LHCGR genes were identified as being independently associated with PCOS. The aim of this study was to identify any additional correlations between the phenotypes of PCOS and genotypes of the five SNPs described in the previous study. STUDY DESIGN, SIZE, DURATION In the present cross-sectional study, a total of 1731 PCOS patients and 4964 controls were enrolled. PARTICIPANTS/MATERIALS, SETTING, METHODS Patients were diagnosed according to Rotterdam criteria. Clinical information was collected from the patients and controls. Endocrine and metabolic parameters were evaluated for phenotype-genotype correlation analyses. MAIN RESULTS AND THE ROLE OF CHANCE Using a recessive model, the AA group for rs13429458 in THADA was associated with increased luteinizing hormone (LH) (P < 0.01) and testosterone (T) (P = 0.02) levels in subjects with PCOS; the LH/follicle-stimulating hormone ratio was also higher in the AA group (P < 0.01). Also using a recessive model, the CC genotype of rs12478601, also in THADA, was associated with increased levels of low-density lipoprotein (P = 0.02). Using a dominant model, the GG + AG group for rs2479106 in DENND1A was associated with elevated serum insulin levels 2 h after a glucose load in the patients with PCOS (P = 0.02). All of the comparisons were adjusted for age and BMI. LIMITATIONS, REASONS FOR CAUTION The relatively younger age of the participants may represent a considerable bias when evaluating metabolic alterations as a function of different genotypes, as significant metabolic disturbances may emerge later in life. Furthermore, the sample sizes of several sub-genotype groups were relatively small; to some extent this limited the statistical power of the analysis. WIDER IMPLICATIONS OF THE FINDINGS The PCOS susceptibility genes, THADA and DENND1A, carry risk alleles that are associated with endocrine and metabolic disturbances in PCOS patients of Han Chinese descent. The findings have shown genuine heterogeneity, stratified on the basis of both clinical findings and genotypes. Replication of these results is expected in other ethnic groups.

Identification of YAP1 as a novel susceptibility gene for polycystic ovary syndrome

Background A previously reported genome-wide association study (GWAS) of polycystic ovary syndrome (PCOS) in Han Chinese found that several loci of p value around 10e-5 warrant investigation. Replication of the GWAS was applied in this study to determine whether gene YAP1 (yeast associated protein 1) is associated with PCOS. Methods An independent set of 1115 PCOS patients and 1137 controls were recruited; single nucleotide polymorphisms (SNPs) rs11225138, rs11225161, and rs11225166 from YAP1 were selected for the replication study. Real-time quantitative PCR was applied for genotyping by TaqMan-MGB probe assay. Results Meta-analysis showed that the allele frequency of rs11225161 (A/G) was significantly different between PCOS and controls at a GWA significance (Pmeta =3.98e-09). Genotype–phenotype correlation study found 30 min and 60 min glucose of the oral glucose tolerance test were higher in PCOS patients with rs11225161 risk allele A. The G allele of SNP rs11225138 (G/C) was a further risk factor for higher luteinising hormone level in PCOS patients (p=0.041). Conclusion YAP1 appears to be a new susceptibility gene for PCOS in Han Chinese women.

Common Variant rs9939609 in Gene FTO Confers Risk to Polycystic Ovary Syndrome

Background Fat mass and obesity-associated gene (FTO) has been associated with obesity, especially the common variant rs9939609. Polycystic ovary syndrome (PCOS) is a complex endocrine-metabolic disorder and over 50% of patients are overweight/obese. Thus FTO is a potential candidate gene for PCOS but their relationship is confusing and remains to be clarified in different population with a large sample size. Method This study was performed adopting a two-stage design by genotyping SNP rs9939609. The first set comprise of 741 PCOS and 704 control subjects, with data from our previous GWAS. The second phase of replication study was performed among another independent group of 2858 PCOS and 2358 control subjects using TaqMan-MGB probe assay. All subjects are from Han Chinese. Results The less meaningful association of FTO rs9939609 and PCOS discovered in GWAS (P = 2.47E-03), was further confirmed in the replication study (P = 1.86E-09). Using meta-analysis, the P-meta value has reached 6.89E-12, over-exceeding the genome-wide association level of 5.00E-8. By combination, the P value was 1.26E-11 and after BMI adjustment it remained significant(P = 1.82E-06). To further elucidate whether this association is resulted from obesity or PCOS per se, the samples were divided into two groups–obese and non-obese PCOS, and the results were still positive in obese group (P obese = 5.81E-05, OR = 1.55), as well as in non-obese PCOS group (P non-obese = 7.06E-04, OR = 1.28). Conclusion Variant rs9939609 in FTO is associated with PCOS in Chinese women, not only in obese PCOS subjects, but also in non-obese cases.

Polycystic ovary syndrome susceptibility single nucleotide polymorphisms in women with a single PCOS clinical feature

STUDY QUESTION What is the direct genetic contribution of the polycystic ovary syndrome (PCOS) susceptibility single nucleotide polymorphisms (SNPs), identified by previous genome-wide association studies (GWAS) to the definitive clinical features of the syndrome? SUMMARY ANSWER Each single PCOS clinical feature had a specific genetic association, and rs4385527 in the chromosome 9 open reading frame 3 (C9orf3) conferred a particular risk to the three defined PCOS clinical features in this study, which suggested its fundamental role in the etiology of PCOS. WHAT IS KNOWN ALREADY PCOS is a heterogeneous disorder characterized by anovulation (OA), hyperandrogenism (HA) and polycystic ovary morphology (PCOM). Two previous GWAS in China have identified 15 independent susceptibility SNPs related to PCOS (PCOS-SNPs). However, little is known about the candidate gene of each clinical feature. STUDY DESIGN, SIZE, DURATION Case-control study. Three independent groups of women were recruited from 2010 to 2012: 746 subjects with OA only, 278 subjects with HA only and 536 subjects with PCOM only. A total of 1790 healthy women with none of the above pathological characteristics were also enrolled as control subjects during the same time period. PARTICIPANTS/MATERIALS, SETTING, METHODS All participants were women of reproductive age. Genotype and allelic frequencies of 15 PCOS-SNPs were determined in all subjects using direct sequencing and Sequenom Arrays. The allelic frequencies of each case group were compared with the controls. MAIN RESULTS AND THE ROLE OF CHANCE After adjustment for age and BMI, variants in luteinizing hormone/choriogonadotropin receptor (LHCGR) (rs13405728), C9orf3 (rs4385527) and insulin receptor gene (INSR) (rs2059807) were strongly associated with OA (Padjust < 0.01, <0.001 and <0.05, respectively); rs4385527 in C9orf3 was strongly associated with HA (Padjust< 0.001); variants in the thyroid adenoma associated gene (THADA) (rs13429458 and rs12478601), DENN/MADD domain containing 1A (DENND1A)(rs10818854), and C9orf3 (rs4385527) were significantly associated with PCOM (Padjust < 0.01, <0.001, <0.05 and <0.001, respectively). LIMITATIONS, REASONS FOR CAUTION The sample size of some case groups was relatively small, which therefore limited the statistical power of the analysis to a certain extent. WIDER IMPLICATIONS OF THE FINDINGS The present study indicates a potential common genetic basis of three PCOS clinical features. Other specific associated genes may play a synergistic role, leading to heterogeneous pathophysiological changes. Additionally, the increased frequency of PCOS-risk alleles in women with single PCOS clinical features suggests that these subjects have an elevated risk of developing the syndrome, although they cannot be currently diagnosed. STUDY FUNDING/COMPETING INTERESTS This research was supported by the National Basic Research Program of China (973 Program) (2012CB944700, 2011CB944502), the National Key Technology Research and Development Program(2011BAI17B00), the National Natural Science Foundation of China (81430029, 81201441, 81490743, 31371453), the Scientific Research Foundation of Shandong Province of Outstanding Young Scientist (2012BSE27089) and the Fundamental Research Funds of Shandong University(2014GN025). There were no competing interests.

Variants in FSHB Are Associated With Polycystic Ovary Syndrome and Luteinizing Hormone Level in Han Chinese Women

CONTEXT A recent genome-wide association study (GWAS) has identified three susceptibility loci (8p32.1, 11p14.1, and 9q22.32) for polycystic ovary syndrome (PCOS) in women of European ancestry. The 9q22.32 locus was previously found in our Chinese PCOS GWAS. Replication of the other two loci is necessary to determine whether the same variants confer risk to PCOS in Han Chinese women. OBJECTIVE This study aimed to investigate the effect of the European GWAS loci on PCOS susceptibility in Han Chinese women. DESIGN, SETTING, AND PATIENTS This was a genetic association study at a university hospital in composed of 1601 PCOS cases and 1238 age-matched controls. Interventions and Main Outcome Measure: After screening of the regions that cover 500 kb upstream and downstream of the two single-nucleotide polymorphisms (SNPs) using our previous Chinese GWAS data, rs11031010, located in the region of follicle-stimulating hormone B polypeptide (FSHB) gene, was selected for further replication. The other SNPs near rs804279 (GATA4/NEIL2) were excluded based on our previous GWAS data. Then, the variant rs11031010 was genotyped in an independent cohort and the associations with PCOS, endocrine and metabolic traits were assessed. RESULTS In the current replication study, rs11031010 was associated with PCOS in Han Chinese women (P = 2.76 × 10(-3)), even after adjustment for age and body mass index. Meta-analysis with our previous GWAS data showed that the allele frequency difference of rs11031010 between PCOS and controls reached genome-wide significance (P = 4.27 × 10(-8)). PCOS women with AA and AC genotypes had a significantly higher LH level than individuals carrying the CC genotype (P =1.60 × 10(-4)). The genetic risk score based on sixteen total Chinese PCOS-risk SNPs, calculated by total number of risk alleles for each subject, was associated with the diagnosis of PCOS (P < 1.00 × 10(-4)). CONCLUSIONS Variants in FSHB gene are associated with PCOS and LH levels in Han Chinese women. FSHB is thus likely to play an important role in the etiology of PCOS, regardless of ethnicity.

Reduced Ectopic Pregnancy Rate on Day 5 Embryo Transfer Compared with Day 3: A Meta-Analysis

Objective To compare the risk of ectopic pregnancy (EP) after embryo transfer on day 3(D3-ET) and day 5(D5-ET). Design Meta-analysis Patients Women with pregnancy resulting from in vitro undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) Result(s) Twenty-two studies were identified through research conducted using the PubMed, Embase, and Cochrane databases and ClinicalTrials.gov. All studies were conducted prior to October 2016. Adding the reproductive data from our center, a total of 143 643 pregnancies were reviewed(D3-ET: n = 62027,D5-ET:n = 81616). A lower EP rate was found in women undergoing D5-ET than in those undergoing D3-ET [relative risk (RR), 0.67;95% confidence interval (CI), 0.54–0.85;143643 pregnancies in 23 studies; I2 = 67%]. These results were validated in subgroups of fresh embryo-transfer (Fre-ET) cycles [RR, 0.78; 95%CI, 0.69–0.88; 91 871 pregnancies in 21 studies; I2 = 29%] and frozen-thawed embryo-transfer (Fro-ET) cycles [RR, 0.43; 95%CI, 0.36–0.51; 51 772 pregnancies in 10 studies; I2 = 33%]. After separating out the randomized controlled trials (RCTs), a significant difference was found in the retrospective studies in both subgroups [both Fre-ET (RR,0.78;95% CI 0.69–0.88);91182 pregnancies in 14 studies; I2 = 45%] and Fro-ET(RR,0.43;95% CI 0.36–0.51; 51751pregnancies in 9 studies;I2 = 33%)], while the RCTs showed no statistical significance for Fre-ET cycles[RR,0.86;95% CI 0.32–2.26); 689 pregnancies in 7 studies; I2 = 0%]. Conclusion(s) The present study indicates that D5-ET reduces the risk for EP in cycles that use IVF or ICSI, compared with D3-ET. It suggests that D5-ET may be a better choice for decreasing the EP rate in assisted reproductive technology. Further high-quality randomized controlled trials are anticipated.

Younger poor ovarian response women achieved better pregnancy results in the first three IVF cycles

This retrospective cohort study observed the live birth rates as well as cumulative live birth rates in women with poor ovarian response (POR) undergoing IVF-embryo transfer treatment, stratified for age and cycle number. Four hundred and one patients with POR diagnosed according to the Bologna criteria were enrolled and 700 IVF-ET cycles were analysed. The overall live-birth rate per cycle was 18.3%. From cycle 1 up to cycle 3, the live-birth rates decreased significantly from 22.2% to 11.1%. The live-birth rate fell to 2.4% in cycles 4 and over. When age advanced, the live birth rates decreased obviously (P < 0.01): 30.0% for women < 35 years old, 17.0% for those 35-40 years old, and 9.0% for women older than 40 years. Similarly, the cumulative live birth rates dropped from 48.0% (< 35 years) to 16.9% (≥ 40 years) accordingly. Younger patients (< 35 years old) with POR achieved better pregnancy results compared with patients of advanced age. Extremely low live-birth rates could be anticipated after three unsuccessful cycles; therefore it may not be appropriate to suggest more IVF cycles in POR women.

Mutational analysis of SKP2 and P27 in Chinese Han women with premature ovarian failure

P27 and SKP2, a major regulator of P27, play a crucial role in ovarian function in mice. Both P27-deficient and SKP2-deficient female mice develop premature ovarian failure (POF). The coding regions of SKP2 and P27 were examined in 200 Chinese women with POF and 200 control volunteers. This study is the first to investigate SKP2 in POF. No plausible pathogenic mutations were detected. The results suggest that mutations in SKP2 and P27 are not common in Chinese Han women with POF.

Chronic Pelvic Inflammation Diminished Ovarian Reserve as Indicated by Serum Anti Mülerrian Hormone.

Objective To explore the potential damaging effect of chronic pelvic inflammation on ovarian reserve. Design Case-control study. Patients A total of 122 women with bilateral tubal occlusion, diagnosed by hysterosalipingography (HSG) and 217 women with normal fallopians were recruited. Measurements Serum anti-Mullerian hormone (AMH), basic follicle-stimulating hormone (FSH), luteining hormone (LH), estradiol (E2), and testosterone (T) were measured; and antral follicle counts (AFCs) were recorded. Results Significantly lower level of AMH was observed in women with bilateral tubal occlusion compared to control group [2.62 (2.95) ng/ml vs. 3.37 (3.11) ng/ml, P = 0.03], and the difference remained after adjustment of BMI (Padjust = 0.04). However, no statistical difference was found in the levels of FSH [7.00 (2.16) IU/L vs. 6.74 (2.30) IU/L], LH [4.18 (1.52) IU/L vs. 4.63 (2.52) IU/L], E2 [35.95 (20.40) pg/ml vs. 34.90 (17.85) pg/ml], T [25.07±11.46 ng/dl vs. 24.84±12.75 ng/dl], and AFC [6.00 (4.00) vs. 7.00 (4.00)] between two groups (p>0.05). Conclusions Women with bilateral tubal occlusion showed decreased AMH level, suggesting that chronic pelvic inflammation may diminish ovarian reserve. More caution should be paid when evaluating the detriment of PID on female fertility.

Low anti-müllerian hormone concentration is associated with increased risk of embryonic aneuploidy in women of advanced age

RESEARCH QUESTION Does an association exist between serum anti-Müllerian hormone (AMH) level, the marker of biological ovarian age, and embryonic aneuploidy risk in recurrent spontaneous miscarriage (RSM) patients of reproductive age? DESIGN This retrospective study included a total of 422 IVF cycles of 394 unexplained RSM patients undergoing preimplantation genetic testing for aneuploidy (PGT-A), enrolled from January 2014 to December 2016. Subjects were divided into three groups according to the 25th (1.50 ng/ml) and 75th (5.60 ng/ml) percentiles of AMH level (Group 1: low AMH <1.50 ng/ml [N = 107], Group 2: normal AMH 1.50- < 5.60 ng/ml [N = 210] and Group 3: high AMH ≥ 5.60 ng/ml [N = 105]). RESULTS There was a significant difference in embryonic aneuploid rate between AMH groups (66.7% versus 42.9% versus 50.0%, Groups 1 to 3, respectively, P = 0.006). It was significantly higher in the low AMH group (Group 1) compared with that in the normal AMH group (Group 2, P1vs2 = 0.002) and high AMH group (Group 3, P1vs3 = 0.015). After age stratification, embryonic aneuploidy rate was still significantly different among AMH groups with a similar trend in women ≥35 years old (68.2% versus 54.4% versus 51.0%, P = 0.038, P1vs2 = 0.025, P1vs3 = 0.035), but not in young subjects. CONCLUSIONS These findings indicate that low AMH level was associated with increased risk of embryo aneuploidy only in women of advanced age. Maternal diminished ovarian reserve along with oocyte ageing may contribute to impaired chromosomal competence of the embryo.