COL1A1 Sp1-binding site polymorphism as a risk factor for genital prolapse

Genetic Etiology in Pelvic Organ Prolapse: Role of Connective Tissue Homeostasis, Hormone Metabolism, and Oxidative Stress

Background: Pelvic organ prolapse (POP) has become a common health problem among the aging population and affects an increasing number of elderly women worldwide. Studies within family and twin pairs provided strong evidence for the contribution of genetic factors to POP. Given the incomplete penetrance, polygenic traits, and small effect sizes of each variant in complex diseases, it is not always easy to evaluate the genetic susceptibility and molecular mechanisms involved in POP. Objectives: This review intends to comprehensively summarize the current studies on genetic variants associated with POP. Methods: We performed a comprehensive review to summarize the genetic findings from genome-linkage studies, genome-wide association studies, candidate association studies, and gene expression analyses. Results: We summarized genetic variants associated with connective tissue homeostasis, hormone metabolism, and oxidative stress, which were potentially related to the pathophysiology of POP. We also reviewed the limited polygenic risk score (PRS) studies generated for each individual's genetic risk stratification and its integration into clinical risk factors for disease prediction. Conclusions: This pooled analysis provides moderate epidemiological credibility for associations of these genetic variants with POP to bridge the gap between genetic research and clinical medicine towards understanding the genetic etiology of POP. It also highlights the potential of PRS as a risk prediction model.

Genetics of Female Pelvic Organ Prolapse: Up to Date

Pelvic organ prolapse (POP) is a benign disease characterized by the descent of pelvic organs due to weakened pelvic floor muscles and fascial tissues. Primarily affecting elderly women, POP can lead to various urinary and gastrointestinal tract symptoms, significantly impacting their quality of life. The pathogenesis of POP predominantly involves nerve-muscle damage and disorders in the extracellular matrix metabolism within the pelvic floor. Recent studies have indicated that genetic factors may play a crucial role in this condition. Focusing on linkage analyses, single-nucleotide polymorphisms, genome-wide association studies, and whole exome sequencing studies, this review consolidates current research on the genetic predisposition to POP. Advances in epigenetics are also summarized and highlighted, aiming to provide theoretical recommendations for risk assessments, diagnoses, and the personalized treatment for patients with POP.

Systematic review and meta-analysis of genetic association studies of pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Family and twin studies demonstrate that pelvic organ prolapse (POP) is heritable, but the genetic etiology is poorly understood. This review aimed to identify genetic loci and specific polymorphisms associated with POP, while assessing the strength, consistency, and risk of bias among reported associations.

METHODS

Updating an earlier systematic review, PubMed and HuGE Navigator as well as relevant conference abstracts were searched using genetic and phenotype keywords from 2015 to 2020. Screening and data extraction were performed in duplicate. Fixed and random effects meta-analyses were conducted using co-dominant models of inheritance. We assessed credibility of pooled associations using interim Venice criteria.

RESULTS

We screened 504 new abstracts and included 46 published and 7 unpublished studies. In pooled analyses we found significant associations for four polymorphisms: rs2228480 at the ESR1 gene (OR 0.67 95% CI 0.46-0.98, I² = 0.0%, Venice rating BAB), rs12589592 at the FBLN5 gene (OR 1.46 95% CI 1.11-1.82, I² = 36.3%, Venice rating BBB), rs484389 in the PGR gene (OR 0.61 95% CI 0.39-0.96, I² = 32.4%, Venice rating CBB), and rs1800012 at the COL1A1 gene (OR 0.80 95% CI 0.66-0.96, I² = 0.0%, Venice rating BAB). Further credible novel variants have also been recently identified in genome-wide association studies.

CONCLUSION

The genetic contributions to POP remain poorly understood. Several biologically plausible variants have been identified, but much work is required to establish the role of these genes in the pathogenesis of POP or to establish a role for genetic testing in clinical practice.

The effect of women's body mass index on pelvic organ prolapse: a systematic review and meta analysis

BACKGROUND

Pelvic organ prolapse remains the public health challenge globally. Existing evidences report the effect of woman's weight on the pelvic organ prolapse inconsistently and this urges the need of pooled body weight effect on the pelvic organ prolapse. Although there was a previous work on this regard, it included papers reported before June 18/2015. Thus, updated and comprehensive evidence in this aspect is essential to devise strategies for interventions.

OBJECTIVE

This review aimed at synthesizing evidence regarding the pooled effect of body weight on the pelvic organ prolapsed.

METHODS

For this review, we searched all available articles through databases including PubMed, Web of Sciences, CINAHL, JBI library, Cochran library, PsycInfo and EMBASE as well as grey literature including Mednar, worldwide science, PschEXTRA and Google scholar. We included cohort, case-control, cross-sectional and experimental studies which had been reported between March 30, 2005 to March 30, 2020. In the effect analysis, we utilized random model. The heterogeneity of the studies was determined by I2 statistic and the publication bias was checked by Egger's regression test. Searching was limited to studies reported in the English language.

RESULTS

A total of 14 articles with 53,797 study participants were included in this systematic review (SR) and meta analysis (MA). The pooled result of this Meta analyses depict that body mass index (BMI) doesn't have statistical significant association with pelvic organ prolapse.

CONCLUSION

This review point out that women's body mass index has no significant effect on the development of pelvic organ prolapse. However, the readers should interpret the result with cautions due to the presence of considerable limitations in this work. Trial registration The protocol of this systematic review (SR) and meta analysis (MA) has been registered in PROSPERO databases with the Registration number of CRD42020186951.

Research progress of single nucleotide polymorphism in stress urinary incontinence

Stress urinary incontinence (SUI), as one of the manifestations of pelvic floor dysfunction diseases with high incidence, seriously affects women's physical and mental health and quality of life. The etiology and pathogenesis of SUI are complex and not yet completely clear, now believed to be involved with environmental factors, genetic factors and cross-cutting factors between the two. SUI genetic susceptibility may be related to single nucleotide polymorphism. This article reviews the current studies on SUI-related single nucleotide polymorphisms.

Family history and pelvic organ prolapse: a systematic review and meta-analysis

INTRODUCTION AND HYPOTHESIS

Numerous analytic observational studies assess family history as a risk factor for POP and report a wide range of associations. This review aims to systematically evaluate the role of family history of POP in relation to POP risk and its recurrence.

METHODS

A review was performed of the PubMed/MEDLINE database with search criteria specifying family history, risk factors, POP, and their synonyms as title/abstract keywords, as well as MESH terms, up to March 2020. We aggregated evidence across studies with fixed effects (FE) and random effects (RE) meta-analysis.

RESULTS

Forty-three articles underwent full-text review. Eighteen independent studies evaluating the relationship between family history of POP and POP risk in 3639 POP cases and 10,912 controls were eligible for meta-analysis. Four studies evaluating family history and POP recurrence in 224 recurrent cases and 400 non-recurrent cases were eligible for inclusion into another meta-analyses. A positive family history of POP is on average associated with 2.3- to 2.7-fold increased risk for POP (RE OR = 2.64; 95% CI = 2.07, 3.35) as well as a 1.4-fold increased risk for POP recurrence (FE OR = 1.44; 95% CI = 1.00, 2.08). Meta-analysis estimates of POP risk varied by study design, definition of family history, and model adjustment status. We found evidence that publication bias and recall bias are a possibility.

CONCLUSIONS

Family history of POP is a risk factor for both POP presence and recurrence. However, reported magnitudes may be overestimates due to confounding, recall bias, and publication bias.

Collagen I and collagen III polymorphisms in women with pelvic organ prolapse

AIMS

Verify the presence of the single nucleotide polymorphisms rs1800012 of the collagen I (COL1A1) and rs1800255 of the collagen III (COL3A1) genes and their association with pelvic organ prolapse (POP) in Brazilian women and to determine risk factors for POP.

METHODS

We assessed 826 postmenopausal women divided into POP (stages III and IV) and control groups (stages 0 and I) by examination and peripheral blood sample collection. DNA sequences of interest were analyzed by real-time reverse-transcriptase polymerase chain reaction. We used logistic regression analyses, recessive and codominance models of inheritance, and P < .05 for significance.

RESULTS

Six-hundred and thirty-four postmenopausal women were included: 348 (54.8%) POP cases and 286 (45.1%) controls. The frequencies of GG, GA, and AA genotypes for COL1A1 were 69.12%, 20.24%, and 10.59% in POP group and 71.79%, 20%, and 8.21% in controls; GG, GT, and TT for COL3A1 were 37.54%, 59.53%, and 2.93% in POP group and 36.24%, 60.14%, and 3.62% in controls. There were no genotypic or allelic association with POP phenotype that link both SNPs rs1800012 and rs1800255 to increased risk of POP. Vaginal delivery (odds ratio [OR] = 13; 95% confidence interval [CI] [4.00-47.08]), POP family history (OR = 3.1; 95% CI [1.49-6.50]), diabetes mellitus (OR = 2.3; 95% CI [1.08-5.21]), number of pregnancies (OR = 1.2; 95% CI [1.05-1.36]), and age (OR = 1.1; 95% CI [1.09-1.19]), were variables of increased risk for POP (P < .05 for all).

CONCLUSION

Our study suggests lack of association between DNA polymorphisms rs1800012 of COL1A1 and rs1800255 of COL3A1 with advanced POP. Vaginal delivery, POP family history, diabetes mellitus, number of pregnancies, and age are risk factors for POP.

Genetic polymorphisms in collagen-related genes are associated with pelvic organ prolapse

OBJECTIVE

Pelvic organ prolapse (POP) is a common health issue that has a profound negative influence on women's quality of life. Genetic susceptibility to POP has been increasingly investigated. In this study, we assessed the single-nucleotide polymorphisms (SNPs) of six collagen-related genes (COL14A1, COL5A1, COL4A2, COL3A1, COL1A1, and COL18A1) and the genetic association with POP in Chinese women.

METHODS

We performed a candidate gene association study of case women (n = 48) with stage III and IV prolapse and control women (n = 48) without prolapse. A target region sequencing approach was used to identify the SNPs in collagen-related genes. The association between SNPs and POP was examined by Fisher exact tests for unadjusted model and logistic regression analysis adjusted for delivery and pregnancy.

RESULTS

There was a significant association between COL14A1 SNPs (rs4870723, rs2305600, and rs2305598; P = 0.013, 0.019, and 0.028, respectively), a COL5A1 SNP (rs3827852; P = 0.016), and COL4A2 SNPs (rs76425569, rs388222, and rs2281968; P = 0.049 for the three, and rs445348, P = 0.040) and POP, respectively. Although there was no significant association between the COL3A1 SNP and POP, there was a trend toward significance for COL14A1 SNP (rs2305603), COL4A2 SNP (rs74941798), two COL1A1 SNPs (rs2586488 and rs2249492) and three COL18A1 SNPs (rs1050351, rs56335679, and rs55690336), and POP.

CONCLUSION

We are the first to evaluate the relationship between COL14A1, COL5A1, and COL4A2 polymorphisms and POP, besides COL3A1, COL1A1, and COL18A1, which have been reported previously. We found several candidate SNPs that were significantly associated with prolapse in Chinese women. Our results provide new evidence for further investigation of the involvement of these potential genes in the etiology of POP.

Association between col1a2 Polymorphism and the Occurrence of Pelvic Organ Prolapse in Brazilian Women

OBJECTIVE

 To evaluate the rs42524 polymorphism of the procollagen type I alpha (α) 2 (COL1A2) gene as a factor related to the development of pelvic organ prolapse (POP) in Brazilian women.

METHODS

 The present study involved 112 women with POP stages III and IV (case group) and 180 women with POP stages zero and I (control group). Other clinical data were obtained by interviewing the patients about their medical history, and blood was also collected from the volunteers for the extraction of genomic DNA. The promoter region of the COL1A2 gene containing the rs42524 polymorphism was amplified, and the discrimination between the G and C variants was performed by digestion of the polymerase chain reaction (PCR) products with the MspA1I enzyme followed by agarose gel electrophoresis analysis.

RESULTS

 A total of 292 women were analyzed. In the case group, 71 had the G/G genotype, 33 had the G/C genotype, and 7 had the C/C genotype. In turn, the ratio in the control group was 117 G/G, 51 G/C, and 11 C/C. There were no significant differences between the groups.

CONCLUSION

 Our data did not show an association between the COL1A2 polymorphism and the occurrence of POP.

Evaluation of COLIA1-1997 G/T polymorphism as a related factor to genital prolapse

INTRODUCTION AND HYPOTHESIS

Pelvic organ prolapse has a multifactorial etiology. There is increasing evidence that genetic factors greatly impact its development. This study aimed to evaluate the possible relation of the collagenous polymorphism -1997 G/T with genital prolapse in Brazilian women.

METHODS

A cohort study of 180 women with stage 0 or I (group A) pelvic organ prolapse disorder and 112 women with stage III or IV (group B) was conducted. Blood DNA was isolated, and the -1997 G/T polymorphism was identified by amplifying a region of the COLIA1 gene starting prior to the protein's coding sequence.

RESULTS

No significant difference in the prevalence of genotypes TG and TT was found between groups (p = 0.67); differences were not found even when patients were grouped by the presence of 0 or ≥ 1 polymorphic alleles (p = 0.46). Age and home birth were found to be independent risk factors for prolapse.

CONCLUSIONS

Our study could not find any association between the -1997G/T polymorphism and genital prolapse in Brazilian women.

Identification of key genes and pathways in pelvic organ prolapse based on gene expression profiling by bioinformatics analysis

PURPOSE

The aim of this study was to elucidate the molecular mechanisms and to identify the key genes and pathways for pelvic organ prolapse (POP) using bioinformatics analysis.

METHODS

The microarray data for GSE53868 included 12 POP and 12 non-POP anterior vaginal wall samples. Differentially expressed genes (DEGs) were identified by GEO2R online tool. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the DAVID database, and a DEG-associated protein-protein interaction (PPI) network was constructed using STRING and visualized in Cytoscape. MCODE was used for module analysis of the PPI network.

RESULTS

A total of 257 upregulated and 333 downregulated genes were identified. GO and KEGG pathway enrichment analyses showed that the upregulated DEGs were strongly associated with immune response, complement activation, classical pathway, phagocytosis, and recognition; the downregulated genes were mainly associated with cellular response to zinc ion, negative regulation of growth, and apoptotic process. Based on the PPI network, IL6, MYC, CCL2, ICAM1, PTGS2, SERPINE1, ATF3, CDKN1A, and CDKN2A were screened as hub genes. The four most significant sub-modules of DEGs were extracted after network module analysis. These genes were mainly associated with the negative regulation of growth and inflammatory response. The KEGG pathway enrichment analysis revealed that these genes were associated with Mineral absorption, Jak-STAT signaling pathway, cytokine-cytokine receptor interaction, and chemokine signaling pathway.

CONCLUSIONS

These microarray data and bioinformatics analyses provide a useful method for the identification of key genes and pathways associated with POP. Moreover, some crucial DEGs, such as IL6, MYC, CCL2, ICAM1, PTGS2, SERPINE1, ATF3, CDKN1A, and CDKN2A, potentially play an important role in the development and progression of POP.

Obesity and pelvic organ prolapse: a systematic review and meta-analysis of observational studies

BACKGROUND

Studies evaluating the association between obesity and pelvic organ prolapse report estimates that range from negative to positive associations. Heterogeneous definitions for pelvic organ prolapse and variable choices for categorizing obesity measures have made it challenging to conduct meta-analysis.

OBJECTIVE

We systematically evaluated evidence to provide quantitative summaries of association between degrees of obesity and pelvic organ prolapse, and identify sources of heterogeneity.

STUDY DESIGN

We searched for all indexed publications relevant to pelvic organ prolapse up until June 18, 2015, in PubMed/MEDLINE to identify analytical observational studies published in English that reported risk ratios (relative risk, odds ratio, or hazard ratio) for body mass index categories in relation to pelvic organ prolapse. Random effects meta-analyses were conducted to report associations with pelvic organ prolapse for overweight and obese body mass index categories compared with women in the normal-weight category (referent: body mass index <25 kg/m²).

RESULTS

Of the 70 studies that reported evidence on obesity and pelvic organ prolapse, 22 eligible studies provided effect estimates for meta-analysis of the overweight and obese body mass index categories. Compared with the referent category, women in the overweight and obese categories had meta-analysis risk ratios of at least 1.36 (95% confidence interval, 1.20-1.53) and at least 1.47 (95% confidence interval, 1.35-1.59), respectively. Subgroup analyses showed effect estimates for objectively measured clinically significant pelvic organ prolapse were higher than for self-reported pelvic organ prolapse. Other potential sources of heterogeneity included proportion of postmenopausal women in study and reported study design.

CONCLUSION

Overweight and obese women are more likely to have pelvic organ prolapse compared with women with body mass index in the normal range. The finding that the associations for obesity measures were strongest for objectively measured, clinically significant pelvic organ prolapse further strengthens this evidence. However, prospective investigations evaluating obesity and pelvic organ prolapse are few.

Systematic review and metaanalysis of genetic association studies of urinary symptoms and prolapse in women

OBJECTIVE

Family studies and twin studies demonstrate that lower urinary tract symptoms and pelvic organ prolapse are heritable. This review aimed to identify genetic polymorphisms tested for an association with lower urinary tract symptoms or prolapse, and to assess the strength, consistency, and risk of bias among reported associations.

STUDY DESIGN

PubMed and HuGE Navigator were searched up to May 1, 2014, using a combination of genetic and phenotype key words, including "nocturia," "incontinence," "overactive bladder," "prolapse," and "enuresis." Major genetics, urology, and gynecology conference abstracts were searched from 2005 through 2013. We screened 889 abstracts, and retrieved 78 full texts. In all, 27 published and 7 unpublished studies provided data on polymorphisms in or near 32 different genes. Fixed and random effects metaanalyses were conducted using codominant models of inheritance. We assessed the credibility of pooled associations using the interim Venice criteria.

RESULTS

In pooled analysis, the rs4994 polymorphism of the ADRB3 gene was associated with overactive bladder (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.7-3.6; n = 419). The rs1800012 polymorphism of the COL1A1 gene was associated with prolapse (OR, 1.3; 95% CI, 1.0-1.7; n = 838) and stress urinary incontinence (OR, 2.1; 95% CI, 1.4-3.2; n = 190). Other metaanalyses, including those for polymorphisms of COL3A1,LAMC1,MMP1,MMP3, and MMP9 did not show significant effects. Many studies were at high risk of bias from genotyping error or population stratification.

CONCLUSION

These metaanalyses provide moderate epidemiological credibility for associations of variation in ADRB3 with overactive bladder, and variation of COL1A1 with prolapse. Clinical testing for any of these polymorphisms cannot be recommended based on current evidence.

Genetic epidemiology of pelvic organ prolapse: a systematic review

Given current evidence supporting a genetic predisposition for pelvic organ prolapse, we conducted a systematic review of published literature on the genetic epidemiology of pelvic organ prolapse. Inclusion criteria were linkage studies, candidate gene association and genome-wide association studies in adult women published in English and indexed in PubMed through Dec. 2012, with no limit on date of publication. Methodology adhered to the PRISMA guidelines. Data were systematically extracted by 2 reviewers and graded by the Venice criteria for studies of genetic associations. A metaanalysis was performed on all single nucleotide polymorphisms evaluated by 2 or more studies with similar methodology. The metaanalysis suggests that collagen type 3 alpha 1 (COL3A1) rs1800255 genotype AA is associated with pelvic organ prolapse (odds ratio, 4.79; 95% confidence interval, 1.91-11.98; P = .001) compared with the reference genotype GG in populations of Asian and Dutch women. There was little evidence of heterogeneity for rs1800255 (P value for heterogeneity = .94; proportion of variance because of heterogeneity, I(2) = 0.00%). There was insufficient evidence to determine whether other single nucleotide polymorphisms evaluated by 2 or more papers were associated with pelvic organ prolapse. An association with pelvic organ prolapse was seen in individual studies for estrogen receptor alpha (ER-α) rs2228480 GA, COL3A1 exon 31, chromosome 9q21 (heterogeneity logarithm of the odds score 3.41) as well as 6 single nucleotide polymorphisms identified by a genome-wide association study. Overall, individual studies were of small sample size and often of poor quality. Future studies would benefit from more rigorous study design as outlined in the Venice recommendations.

Recent studies of genetic dysfunction in pelvic organ prolapse: the role of collagen defects

Gynaecologists are becoming increasingly aware that women with a family history of prolapse are at an increased risk of prolapse refractory to treatment. In the past five years, several genetic mutations have been shown to correlate with increased prolapse susceptibility. These mutations can result in disordered collagen metabolism, which weaken the fascial support of the pelvic organs. This review examines the contemporary evidence regarding the role of collagen in prolapse.

Combined effects of collagen type I alpha1 (COL1A1) Sp1 polymorphism and osteoporosis risk factors on bone mineral density in Turkish postmenopausal women

Identification of risk factors for osteoporosis has been essential for understanding the development of osteoporosis. The collagen type I alpha1 (COL1A1) gene is suggested to be implicated in reduced bone mineral density (BMD) in osteoporosis. In the present study, the investigation of the effects of Sp1 polymorphic variants of COL1A1 gene on BMD values, and the determination of the association between COL1A1 Sp1 gene variants and osteoporosis risk factors in the context of gene-environment interaction in Turkish postmenopausal women were aimed. For the detection of COL1A1 Sp1 polymorphism, PCR-RFLP techniques have been used. BMD for lumbar spine (L1-L4) and hip (femoral neck and total hip) was measured by DXA. This study was carried out using a sample of 254 postmenopausal women. We observed a trend decrease in BMD values in the subjects with "ss" genotype having lower BMD of lumbar spine, femoral neck and total hip than those with "SS" and "Ss" genotype, however the differences did not reach statistical significance (P>0.05). We also found that the frequencies of the BMD under mean values at the femoral neck (57.5%) and total hip (76.2%) increased considerably in the subjects carrying "Ss/ss" genotypes in combination of having family history of osteoporosis (61.5% for femoral neck) and smoking history (90.0% for total hip). This population-based study indicates that COL1A1 Sp1 polymorphism may contribute to the development of osteoporosis in combination of osteoporosis risk factors in Turkish postmenopausal women.

Phenotyping clinical disorders: lessons learned from pelvic organ prolapse

Genetic epidemiology, the study of genetic contributions to risk for disease, is an innovative area in medicine. Although research in this arena has advanced in other disciplines, few genetic epidemiological studies have been conducted in obstetrics and gynecology. It is crucial that we study the genetic susceptibility for issues in women's health because this information will shape the new frontier of personalized medicine. To date, preterm birth may be one of the best examples of genetic susceptibility in obstetrics and gynecology, but many areas are being evaluated including endometriosis, fibroids, polycystic ovarian syndrome, and pelvic floor disorders. An essential component to genetic epidemiological studies is to characterize, or phenotype, the disorder to identify genetic effects. Given the growing importance of genomics and genetic epidemiology, we discuss the importance of accurate phenotyping of clinical disorders and highlight critical considerations and opportunities in phenotyping, using pelvic organ prolapse as a clinical example.

Comprehensive analysis of LAMC1 genetic variants in advanced pelvic organ prolapse

OBJECTIVE

We sought to comprehensively evaluate the association of laminin gamma-1 (LAMC1) and advance pelvic organ prolapse.

STUDY DESIGN

We conducted a candidate gene association of patients (n = 239) with stages III-IV prolapse and controls (n = 197) with stages 0-I prolapse. We used a linkage disequilibrium (LD)-tagged approach to identify single-nucleotide polymorphisms (SNPs) in LAMC1 and focused on non-Hispanic white women to minimize population stratification. Additive and dominant multivariable logistic regression models were used to test for association between individual SNPs and advanced prolapse.

RESULTS

Fourteen SNPs representing 99% coverage of LAMC1 were genotyped. There was no association between SNP rs10911193 and advanced prolapse (P = .34). However, there was a trend toward significance for SNPs rs1413390 (P = .11), rs20563 (P = .11), and rs20558 (P = .12).

CONCLUSION

Although we found that the previously reported LAMC1 SNP rs10911193 was not associated with nonfamilial prolapse, our results support further investigation of this candidate gene in the pathophysiology of prolapse.

A systematic review of clinical studies on hereditary factors in pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

There is growing evidence that pelvic organ prolapse (POP) is at least partly caused by underlying hereditary risk factors. The aim of our study was to provide a systematic literature review and meta-analysis of clinical studies on family history of POP as a risk factor for POP in individual women.

METHODS

The databases PubMed and Embase were searched. Clinical studies reporting on family history of POP in relation to POP in individual women were included.

RESULTS

Sixteen studies were included, of which eight enabled us to calculate a pooled odds ratio (OR). The pooled OR of POP in case of a positive family history of POP was 2.58 (95 % confidence interval 2.12-3.15).

CONCLUSIONS

Women with POP are substantially more likely to have family members with the same condition compared to women without POP. This strengthens the hypothesis that genetic predisposition plays an important role in the development of POP.

Pelvic floor disorders: linking genetic risk factors to biochemical changes

Pelvic floor disorders (PFDs) such as stress urinary incontinence (SUI) and pelvic organ prolapse (POP) may share a common pathophysiological process related to pelvic floor tissue laxity and loss of support. We reviewed recent literature on observed biochemical changes in women with SUI and POP, linking them to genetic predisposition. We found that studies of pelvic tissues showed differences between control subjects and women with POP and SUI in collagen and elastin structure at a molecular and fibrillar level. Studies were heterogeneous but showed a trend towards decreased collagen and elastin content. The contribution of matrix metalloproteinases to increased collagenolysis can be related to genetic polymorphisms present in higher frequency in women with PFD. Extracellular matrix (ECM) protein turnover plays a role in the development of POP and SUI, but much remains to be understood of this complex dynamic interplay of enzymes, proteins and molecules. Genotyping of candidate genes participating in ECM formation will elucidate the missing link between the manifestation of the disease and the biochemical changes observed systematically, in addition to those in the pelvic floor.

Pelvic organ prolapse and collagen-associated disorders

Introduction and hypothesis

Pelvic organ prolapse (POP) and other disorders, such as varicose veins and joint hypermobility, have been associated with changes in collagen strength and metabolism. We hypothesized that these various disorders were more prevalent in both POP patients and their family members.

Methods

In this study, the prevalence of various collagen-associated disorders, including POP, was compared between POP patients (n = 110) and control patients (n = 100) and their first and second degree family members.

Results

POP patients reported a higher prevalence of varicose veins, joint hypermobility and rectal prolapse and were more likely to have family members with POP as compared to the control group (p < 0.01). In contrast, the family members of the POP group did not report a higher prevalence of collagen-associated disorders compared to the family members of the control group (p = 0.82).

Conclusions

POP and other collagen-associated disorders may have a common aetiology, originating at the molecular level of the collagens.

Genetics of pelvic organ prolapse: crossing the bridge between bench and bedside in urogynecologic research

An increasing number of scientists have studied the molecular and biochemical basis of pelvic organ prolapse (POP). The extracellular matrix content of the pelvic floor is the major focus of those investigations and pointed for potential molecular markers of the dysfunction. The identification of women predisposed to develop POP would help in the patients' management and care. This article includes a critical analysis of the literature up to now; discusses implications for future research and the role of the genetics in POP.

The relationship between the Trp 64 Arg polymorphism of the beta 3-adrenoceptor gene and idiopathic overactive bladder

OBJECTIVE

The purpose of this study was to verify the association between the Trp 64 Arg polymorphism and idiopathic overactive bladder (OAB) syndrome.

STUDY DESIGN

A case-control study was conducted with 218 women. The case group consisted of 49 patients with OAB symptoms; the control group included 169 women without urinary symptoms. The studied polymorphism was detected by restriction fragment length polymorphism analysis. The χ(2) test was used to compare categoric data, with a significance level of 5%. Numeric data were compared with the use of the parametric t test or nonparametric Mann-Whitney U test.

RESULTS

The distribution of the polymorphism in the investigated women was digested homozygous T allele 69.75%, heterozygotes 29.8%, and homozygous A allele 0.45%. A comparison between the groups showed higher prevalence of the digested homozygous T allele genotype in women with OAB syndrome (P = .001). Multiple logistic regression analysis identified that a family history of OAB syndrome was an independent risk factor for OAB syndrome.

CONCLUSION

The Trp 64 Arg polymorphism was associated with OAB syndrome in the Brazilian population.

Sp1 collagen I A1 polymorphism in women with stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is in part attributed to qualitative and quantitative changes in connective tissue of the urogenital tract. We examined the association of collagen type I a1 (COLIA 1) Sp1 polymorphism with the risk of SUI.

METHODS

Forty-five postmenopausal women suffering from urodynamically verified SUI (study group) were compared to 45 healthy volunteers (control). DNA was extracted from peripheral blood. The genotyping concerning the type 1 a1 collagen gene Sp1 polymorphism was performed with polymerase chain reaction.

RESULTS

The polymorphic T allele was overrepresented in the SUI patients (63.2% versus 36.8%, p = 0.016). Odds ratio for SUI in women harboring the T allele was 2.19 (95% CI 1.149-4.176) compared to women with the wild-type genotype.

CONCLUSIONS

The COLIA1 Sp1 polymorphism is associated with increased prevalence of stress urinary incontinence in postmenopausal women.

Difference in expression of collagen type I and matrix metalloproteinase-1 in uterosacral ligaments of women with and without pelvic organ prolapse

OBJECTIVE

To compare the expression of collagen type I and matrix metalloproteinase-1 (MMP-1) in uterosacral ligament biopsies from women with and without pelvic organ prolapse (POP).

STUDY DESIGN

Uterosacral ligament biopsies were obtained from women with POP (n=46) and control subjects (n=49). Immunohistochemistry for collagen type I and MMP-1 was performed on formalin-fixed and paraffin-embedded sections. The two groups were matched for age, body mass index, parity and postmenopausal status. Statistical Package for the Social Sciences Version 13.0 was used for statistical analysis.

RESULTS

The expression of collagen type I (p=0.034) and MMP-1 (p=0.038) differed between women with POP and control subjects. There was increased expression of MMP-1 and decreased expression of collagen type 1 in uterosacral ligaments of women with POP compared with control subjects.

CONCLUSIONS

This difference indicates a possible relationship between POP and the immunohistochemical expression of collagen type I and MMP-1 in uterosacral ligaments.

Urinary incontinence and vaginal squeeze pressure two years post-cesarean delivery in primiparous women with previous gestational diabetes mellitus

OBJECTIVE

To assess the prevalence of urinary incontinence and associated vaginal squeeze pressure in primiparous women with and without previous gestational diabetes mellitus two years post-cesarean delivery.

METHODS

Primiparous women who delivered by cesarean two years previously were interviewed about the delivery and the occurrence of incontinence. Incontinence was reported by the women and vaginal pressure evaluated by a Perina perineometer. Sixty-three women with gestational diabetes and 98 women without the disease were screened for incontinence and vaginal pressure. Multiple logistic regression models were used to evaluate the independent effects of gestational diabetes.

RESULTS

The prevalence of gestational incontinence was higher among women with gestational diabetes during their pregnancies (50.8% vs. 31.6%) and two years after a cesarean (44.8% vs. 18.4%). Decreased vaginal pressure was also significantly higher among women with gestational diabetes (53.9% vs. 37.8%). Maternal weight gain and newborn weight were risk factors for decreased vaginal pressure. Maternal age, gestational incontinence and decreased vaginal pressure were risk factors for incontinence two years after a cesarean. In a multivariate logistic model, gestational diabetes was an independent risk factor for gestational incontinence.

CONCLUSIONS

The prevalence of incontinence and decreased vaginal pressure two years post-cesarean were elevated among women with gestational diabetes compared to women who were normoglycemic during pregnancy. We confirmed an association between gestational diabetes mellitus and a subsequent decrease of vaginal pressure two years post-cesarean. These results may warrant more comprehensive prospective and translational studies.

Risk factors for recurrence of genital prolapse

PURPOSE OF REVIEW

To review the available evidence regarding those risk factors potentially predicting a recurrence of pelvic organ prolapse (POP).

RECENT FINDINGS

POP is a very common condition in parous women, requiring very often a surgical treatment which may need to be repeated in up to 29% of cases. In the past few years, researchers have focused their attention on the evaluation of risk factors involved in either POP development or recurrence. Recent papers have reported the importance of genetic factors that could be responsible for an inherited weakness of the pelvic floor, predisposing to POP occurrence and/or recurrence. Moreover, a history of genital prolapse at the time of an elective hysterectomy, as well as an inappropriate reconstructive surgical procedure, can predict and be associated with POP development.

SUMMARY

POP recurrence can be associated with a combination of predisposing, inciting, and intervening factors. Based on actual knowledge, it is not possible to weight or score the importance of each single risk factor reported in literature for the development of POP recurrence. Larger series (collected with validated diagnostic and therapeutic tools) and longer follow-up are, therefore, needed to draw definitive conclusions on this issue.

Polymorphism of a COLIA1 gene Sp1 binding site in Korean women with pelvic organ prolapse

PURPOSE

To evaluate the possible influence of G-->T substitution at the Sp1-binding site of the COLIA1 gene on the risk of pelvic organ prolapse (POP).

MATERIALS AND METHODS

The study group consisted of 15 women with advanced stage POP. Fifteen control subjects with uterine myomas among the postmenopausal women were matched for age and parity. DNA was obtained from peripheral blood leukocytes. The fragments of the first intron of the COLIA1 gene were amplified by real time polymerase chain reaction. The polymorphism was identified using LightCycler Technology with hybridization probes. Sequencing reactions were performed on each template using commercial primer.

RESULTS

Two groups had no significant difference in medical history, surgical, and smoking history. The homozygous peaks in two groups were noted at 57 on melting curve analysis. Sequencing reactions confirmed the G/G alleles in the 30 specimens tested. We could not find any polymorphism at the Sp1-binding site in COLIA1 gene with advanced stage POP. Statistical significance was considered to be p < .05.

CONCLUSION

The polymorphism of the Sp1-binding site in the COLIA1 gene did not contribute to the development of POP in Korea.

COL3A1 2209G>A is a predictor of pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

A familial tendency has been demonstrated in the etiology of pelvic organ prolapse (POP), but the specific genetic defects have not been identified. Type III collagen is an important factor in the repair of connective tissue, and gene polymorphisms may impair the tensile strength. We hypothesized that polymorphisms in the alpha I chain of the type III collagen protein-encoding gene (COL3A1) pose women at risk for POP.

METHODS

In this case-control study, the prevalence of type III collagen polymorphisms was compared in women with and without signs and symptoms of POP.

RESULTS

Two hundred and two POP patients and 102 normal parous controls were included. A homozygous single-nucleotide substitution in the coding region of type III collagen (COL3A1 2209G>A, rs1800255) was identified in 27 (13%) POP patients and three (3%) controls (odds ratio, 5.0; 95% confidence interval, 1.4-17.1).

CONCLUSIONS

The probability of POP was higher in women with COL3A1 2209G>A. This polymorphism showed to be a relevant risk factor for POP.

Does COLIA1 SP1-binding site polymorphism predispose women to pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS

COLIA1 polymorphism is associated with increased risk for stress urinary incontinence. We hypothesize that a similar association exists with pelvic organ prolapse (POP).

METHODS

Patients with advanced prolapse and healthy controls were evaluated by interview, validated questionnaires, and pelvic examination. DNA was extracted from peripheral blood, and polymerase chain reaction was performed to determine the presence or absence of the polymorphism. Power calculation indicated the need for 36 patients in each arm.

RESULTS

The prevalence of the polymorphic heterozygous genotype (GT) in the study and control groups was 33.3% and 19.4%, respectively, leading to an odds ratio of 1.75. This difference, however, did not reach statistical significance (p = 0.27).

CONCLUSIONS

The COLIA1 polymorphism was not significantly associated with increased risk for POP.