Evaluation of demographic, clinical characteristics, and genetic polymorphism as risk factors for pelvic organ prolapse in brazilian women

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.

PEOPLE: Lifestyle and comorbidities as risk factors for pelvic organ prolapse-a systematic review and meta-analysis PEOPLE: PElvic Organ Prolapse Lifestyle comorbiditiEs

INTRODUCTION AND HYPOTHESIS

The literature is scarce regarding the effects of comorbidities, clinical parameters, and lifestyle as risk factors for pelvic organ prolapse (POP). This study was performed to systematically review the literature related to body mass index (BMI), waist circumference, diabetes mellitus (DM), hypertension (HT), dyslipidemia, chronic constipation, smoking, chronic cough, occupation, and striae and varicose veins as determinants for POP.

METHODS

Search terms in accordance with Medical Subject Headings were used in PubMed, Embase, LILACS, and the Cochrane Library. Clinical comparative studies between women with and without POP and containing demographic and/or clinical raw data related to lifestyle and/or comorbidities were included. The ROBINS-I (risk of bias in non-randomized studies of interventions) instrument was used. Fixed-effects and random-effects models were used for homogeneous and heterogeneous studies, respectively.

RESULTS

Forty-three studies were included in the meta-analysis. BMI < 25 kg/m2 was found to be a protective factor for POP [OR 0.71 (0.51, 0.99); p = 0.04], and BMI > 30 kg/m2 was a risk factor for POP [OR 1.44 (1.37, 1.52); p < 0.00001]. Waist circumference (≥ 88 cm) was reported as a risk factor for POP [OR 1.80 (1.37, 2.38); p < 0.00001], along with HT [OR 1.18 (1.09, 1.27); p = 0.04], constipation [OR 1.77 (1.23, 2.54); p < 0.00001], occupation [OR 1.86 (1.21, 2.86); p < 0.00001], persistent cough [OR 1.52 (1.18, 1.94); p < 0.0001]), and varicose veins [OR 2.01 (1.50, 2.70); p = 0.12].

CONCLUSIONS

BMI < 25 kg/m2 is protective while BMI > 30 kg/m2 is a risk factor for POP. Large waist circumference, dyslipidemia, HT, constipation, occupation, persistent cough, and varicose veins are also determinants for POP.

Collagen type 3A1 and 1A1 polymorphisms in women with pelvic organ prolapse and urinary incontinence assessed with Sanger sequencing method

Introduction

This case-control trial investigates the prevalence of COL3A1 and COL1A1 gene polymorphisms in female patients suffering pelvic organ prolapse (POP) and stress urinary incontinence (SUI) in comparison with controls.

Material and methods

Inclusion criteria were having one or more risk factors for SUI and POP. Exclusion criteria were hereditary connective tissue diseases as well as surgeries for POP/SUI for the control group. The rs1800255 polymorphism in COL3A1 gene was considered as a local substitution of guanine (G) for adenine (A). The rs1800012 polymorphism in COL1A1 gene was considered as a local substitution of guanine (G) for thymine (T). Genotyping was performed by Sanger sequencing method, followed by estimation of sensitivity and specificity for POP and SUI.

Results

Fifty-two patients with POP and SUI (mean age 64.4 years) and 21 women were included in the control group (mean age 63.2 years). Homozygous genotype (AA) in COL3A1 was found in 10% of patients suffering from POP or SUI. No women in the control group had this genotype. The single nucleotide polymorphism (SNP) had high specificity (1.0) for POP/SUI, but low sensitivity (0.1). Heterozygous genotype (AG) in COL3A1 had a sensitivity equal to 0.47 and specificity of 0.62. Homozygous genotype (TT) in COL1A1 was found in only 2% of patients with POP/SUI, but was not found in controls. Heterozygous genotype (TG) in COL1A1 has sensitivity equal to 0.25 and specificity of 0.74.

Conclusions

POP/SUI patients have specific SNPs in COL1A1 and COL3A1 sequenced by Sanger method.

Advances in molecular mechanisms of pelvic organ prolapse (Review)

Pelvic organ prolapse (POP) is a common gynecological benign disease occurring in middle-aged and elderly females. Its incidence increases every year. To date, the majority of studies investigating its etiology have not evaluated the underlying molecular mechanisms, which has caused substantial difficulties in the prevention, treatment and prognosis of POP. In the present narrative review, recent research studies concerning the molecular mechanisms of POP were systematically reviewed and the advances were summarized. The association between the incidence of POP and the reduction of the extracellular matrix, activation of oxidative stress, genetic susceptibility, denervation of the pelvic floor and reduction of estrogen infiltration were explored. POP is mainly associated with damage of pelvic floor muscles and connective tissue, which are directly caused by pregnancy and vaginal delivery. The majority of the molecular and genetic mutations associated with POP involve specific components of connective tissue synthesis and degradation. It is likely that macroscopic parameters, such as anatomy, lifestyle and reproductive factors, interact with microscopic parameters, such as physiology and genetics in the female pelvic floor, leading to POP. Additional research studies investigating the molecular mechanisms of POP should be performed, since they may aid public health strategies. In the present narrative review, a summary of these molecular mechanisms underlying the development of POP is provided. This included the relevant proteins and genes involved. On this basis, countermeasures were proposed.

COL3A1 rs1800255 polymorphism is associated with pelvic organ prolapse susceptibility in Caucasian individuals: Evidence from a meta-analysis

Background

The collagen 3 alpha 1 (COL3A1) rs1800255 polymorphism has been reported to be associated with women pelvic organ prolapse (POP) susceptibility, but the results of these previous studies have been contradictory. The objective of current study is to explore whether COL3A1 rs1800255 polymorphism confers risk to POP.

Methods

Relevant literatures were searched by searching databases including Pubmed, Embase, Google academic, the Cochrane library, China National Knowledge Infrastructure (CNKI). Search time is from database foundation to March 2021.

Results

A total of seven literatures were enrolled in the present meta-analysis, including 1642 participants. Overall, no significant association was found by any genetic models. In subgroup analysis based on ethnicity, significant associations were demonstrated in Caucasians by allele contrast (A vs. G: OR = 1.34, 95%CI = 1.03–1.74,), homozygote comparison (AA vs. GG: OR = 3.25, 95%CI = 1.39–7.59), and recessive genetic model (AA vs. GG/GA: OR = 3.22, 95%CI = 1.40–7.42).

Conclusions

The present meta-analysis suggests that the COL3A1 is a candidate gene for POP susceptibility. Caucasian individuals with A allele and AA genotype have a higher risk of POP. The COL3A1 rs1800255 polymorphism may be risk factor for POP in Caucasian population.

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.

Investigating Pelvic Floor Muscle Strength in Women of Reproductive Age and Factors Affecting It

This descriptive study was designed to investigate the pelvic floor muscle strength (PFMS) of women aged 18 to 49 years and to examine the factors that may have an effect on PFMS. The study was conducted on 258 women who visited a gynecology outpatient clinic between January 2019 and January 2020, who met the research criteria, and who agreed to participate in the study. The data were collected using the Sociodemographic Characteristics Information Form. The Modified Oxford Scale (MOS) and a perineometer were used to evaluate the PFMS of the women. The mean PFMS value measured using the perineometer was 31.56 ± 12.17 cmH₂O (moderate pressure). The PFMS values were 20.00 to 29.9 cmH₂O (weak pressure) and 30.00 to 39.9 cmH₂O (moderate pressure) in 23.6% of the women, respectively. The PFMS values measured with MOS were of grade 3 strength (moderate pressure) in 23.6% of the women and grade 2 strength (weak pressure) in 23.3%. A statistically significant strong correlation was found between the perineometer measurement and the women's MOS values. Moreover, a statistically significant difference was found between the PFMS values measured with the perineometer, MOS scores, and women's age groups, educational status, marital status, employment status, income status, persistent cough, use of nicotine, alcohol and coffee consumptions, chronic constipation, history of frequent urinary tract infections, regular exercise, body mass index, history of pregnancy, mode of delivery, use of episiotomy at birth, perineal rupture at birth, use of forceps vacuum at birth, multiple pregnancies, delivery of a baby weighing ≥4,000 g, treatment during pregnancy, hysterectomy, menopause, frequency of sexual intercourse, and pain during sexual intercourse (p < .05). We conclude that most of the women in the study had weak to moderate PFMS, that the evaluation of PFMS with the MOS positively overlapped with the perineometric measurements, and that a number of sociodemographic and obstetric variables act as risk factors that affect PFMS. The PFMS of all women should be assessed as part of their routine gynecological examinations.

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.

Identification of pelvic organ prolapse risk susceptibility gene SNP locus in Xinjiang women

INTRODUCTION AND HYPOTHESIS

Susceptibility genes play an important role and have regional specificity in the occurrence of pelvic organ prolapse (POP). This study aims to identify POP susceptibility genes and their loci in ethnic minorities with different genetic backgrounds from Xinjiang in China, providing a theoretical basis for early POP diagnosis, treatment and prevention.

METHODS

Genomic DNA from peripheral blood of 196 patients was prepared; there were 88 POP patients and 108 non-pelvic floor dysfunction patients. We selected 16 different susceptibility gene single-nucleotide polymorphism (SNP) loci, which had been identified as associated with POP risk by researchers in other countries, and carried out genotyping through the Snapshot reaction. The allele and genotype frequencies, odds ratio (OR) and 95% confidence interval (CI) were analyzed using SPSS 17.0 software.

RESULTS

The genotypic and allelic distributions demonstrated significant differences between the patients and the control subjects in the group of minority women, details are as follows: ESR1 rs17847075 AG: OR = 2.738, 95% CI = 1.067-7.025, P = 0.041; ESR1 rs2234693 TC: OR = 2.99, 95% CI = 1.163-7.684, P = 0.024; ZFAT rs1036819 CC: OR = 10.286, 95% CI = 1.158-91.386, P = 0.036; allele C: OR = 2.212, 95% CI = 1.146-4.269; P = 0.02; FBLN5 rs12589592 AA: OR = 0.111, 95% CI = 0.013-0.952, P = 0.029; allele A: OR = 0.482, 95% CI = 0.254-0.913, P = 0.028.

CONCLUSIONS

ESR1 rs17847075 genotype AG in the dominant model (P = 0.008) or heterozygous model (P = 0.045), ESR1 rs2234693 genotype TC in the dominant model (P = 0.008) or heterozygous model (P = 0.028), and ZFAT rs1036819 genotype CC and allele C in the recessive model (P = 0.042) were significantly associated with POP risk in Xinjiang woman.

Polymorphism rs1800255 from COL3A1 gene and the risk for pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Genetic variations of type III collagen may compromise the supportive structures of the female pelvic floor and consequently favor pelvic organ prolapse. The single nucleotide polymorphism G/A rs1800255 located in the coding region for type III collagen (COL3A1) was evaluated as a risk factor for pelvic organ prolapse.

METHODS

A single-center prospective cohort study including women with clinical diagnosis of stage III and IV prolapse (POP group) and prolapse stage 0 or I (control group). Sociodemographic, clinical data and obstetric history were retrieved by physician interview. DNA including the rs1800255 polymorphism was amplified by polymerase chain reaction from blood genomic cells and digested with AluI restriction enzyme for distinction of G and A variants. Qualitative variables were compared using the chi-square and Fisher's exact tests and unpaired t-test for quantitative variables. After stratification of the groups, risk factors for POP were estimated using odds ratios (ORs) from the binary logistic regression model.

RESULTS

A total of 292 women were included, 112 in the POP group and 180 in the control group. There was no significant difference between groups regarding rs1800255. Age and home birth were the only significant risk factors for pelvic organ prolapse.

CONCLUSION

Polymorphism rs1800255 from COL3A1 gene was not a risk factor for pelvic organ prolapse.

Pelvic organ prolapse in Caucasian and East Asian women: a comparative study

OBJECTIVE

Ethnicity has been suggested to be a significant risk factor for pelvic organ prolapse (POP); yet, pelvic organ descent in different ethnic groups, especially in Asian populations, is not well studied. The aim of this study was to compare prolapse stages, pelvic organ descent and hiatal dimensions between East Asian and Caucasian women presenting with symptoms of POP.

METHODS

This was a prospective observational study of East Asian and Caucasian women presenting with symptoms of POP to a tertiary urogynecology clinic in, respectively, Hong Kong and Sydney. Demographic data, prolapse symptoms and prolapse stage were assessed. Physical examination was performed using the pelvic organ prolapse quantification (POP-Q) system. All women underwent transperineal ultrasound using Voluson systems. Offline analysis of four-dimensional ultrasound volume data was performed at a later date, by one operator blinded to all clinical data, to ascertain pelvic organ descent and hiatal dimensions on Valsalva maneuver. Levator muscle avulsion was assessed in volumes obtained on pelvic floor muscle contraction. Multiple logistic regression analysis was performed to assess factors associated with prolapse on clinical and ultrasound examinations.

RESULTS

A total of 225 East Asian women were included between July 2012 and February 2014 from the Hong Kong clinic and 206 Caucasian women between January 2015 and July 2016 from the Sydney clinic. There was no significant difference in the overall staging of prolapse. However, in East Asian women, compared with Caucasians, apical compartment prolapse was more common (99.6% vs 71.8%, P < 0.001) and posterior compartment prolapse less common (16.9% vs 48.5%, P < 0.001) on POP-Q examination. On Valsalva maneuver, the position of the uterus was lower in East Asian than in Caucasian women (-11.3 vs 1.35 mm, P < 0.001), while the rectal ampulla position was lower in Caucasians than in East Asians (-10.6 vs - 4.1 mm, P < 0.001). On multiple regression analysis, Caucasian ethnicity was a significant factor for lower risk of apical compartment prolapse on clinical assessment (odds ratio (OR), 0.01; P < 0.001) and on ultrasound (OR, 0.13; P < 0.001), and for a higher risk of posterior compartment prolapse on clinical assessment (OR, 4.36; P < 0.001) and of true rectocele on ultrasound (OR, 8.14; P < 0.001).

CONCLUSIONS

East Asian women present more commonly with uterine prolapse while Caucasians show more often posterior compartment prolapse. Ethnicity was a significant predictor of type of prolapse on multivariate analysis. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

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.

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.

Collagen type III alpha 1 polymorphism (rs1800255, COL3A1 2209 G>A) assessed with high-resolution melting analysis is not associated with pelvic organ prolapse in the Dutch population

INTRODUCTION AND HYPOTHESIS

The rs1800255, COL3A1 2209 G>A polymorphism in the alpha 1 chain of collagen type III has been associated with an increased risk of pelvic organ prolapse (POP). In one of our previous studies however, polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) misdiagnosed rs1800255, COL3A1 2209 G>A in 6 % of cases. The high-resolution melting (HRM) analysis on the contrary obtained a 100 % accordance for this specific polymorphism and was used in the present study to validate this risk factor for POP.

METHODS

In this case-control study, women with and without symptoms of POP were included and compared. DNA was extracted from blood samples. HRM analysis was used to assess for the presence of the homozygous rs1800255. Groups were compared using the Pearson chi-square, Mann-Whitney, and t tests. The discrepancy between HRM and PCR-RFLP results was investigated using PCR-RFLP results available from our previous study.

RESULTS

The study included 354 women: 272 patients with POP and 82 controls; 18 (7 %) cases versus 3 (4 %) controls had a homozygous rs1800255, COL3A1 2209 G>A polymorphism (odds ratio 1.9, 95 % confidence interval 0.5-6.9, compared to the wild type), and thus no association between POP and the homozygous polymorphism could be demonstrated. A discrepancy between HRM and PCR-RFLP results was found in 8 % of the samples.

CONCLUSIONS

The previously found statistically significant association between the rs1800255, COL3A1 2209 G>A polymorphism as measured with PCR-RFLP and POP could no longer be demonstrated. This raises concerns regarding the results of other association studies using PCR-RFLP.

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.