Endometriosis: Update of Pathophysiology, (Epi) Genetic and Environmental Involvement

Menstrual products: culprits or bystanders in endometriosis and adenomyosis pathogenesis?

Products that may reduce menstrual flow from the endometrial cavity to the vagina (i.e. tampons and menstrual cups) could facilitate retrograde menstruation and the spillage of blood into the myometrium, two mechanisms which could be major determinants in endometriosis and adenomyosis pathogenesis. The aim of this narrative review is to summarize the evidence regarding the mechanical role menstrual products may have in the pathogenesis of these two conditions. Evidence in this regard is inconclusive. While Darrow and colleagues observed that 14 or more years of tampon use were associated with endometriosis (OR 3.6; 95% CI, 1.04-13.5); in Meaddough and colleagues' retrospective study, the percentage of women using pads only was significantly higher among those with endometriosis than among those without the condition (31% vs 22%). Three further groups failed to find an association between endometriosis/adenomyosis and any type of menstrual product. The only case that may be considered as a sort of proof-of-concept of the association between products potentially reducing anterograde menstrual flow and endometriosis was reported by Spechler and colleagues, who described the case of a 41 year-old who developed endometriosis after having used a menstrual cup on a regular basis. However, the number of studies on the subject is scarce, study populations are exiguous and a greater attention to temporality of endometriosis onset in relation to when women started habitually using a specific menstrual product is needed. Confounding variables including type and quantity of endocrine disruptors contained in menstrual products should also be addressed. At the present moment, no recommendation can be provided on the safety of one type of menstrual product compared to another.

Association between the Exposure to Phthalates and the Risk of Endometriosis: An Updated Review

Endometriosis is a chronic gynecological disease, primarily associated with pelvic pain and infertility, that affects approximately 10% of the women of reproductive age. Estrogen plays a central role in endometriosis, and there is growing evidence that endocrine disruptors, such as phthalates, may contribute to its development. This review aimed to determine whether there is a causal relationship between phthalate exposure and the development of endometriosis, as well as the possible effects of phthalates on fertility, by analyzing epidemiological data. After a literature search with a combination of specific terms on this topic, we found that although there are limitations to the current studies, there is a clear association between phthalate exposure and endometriosis. Phthalates can interfere with the cellular processes of the endometrium; specifically, they can bind to PPAR and ER-α and activate TGF-β, promoting different signaling cascades that regulate the expression of specific target genes. This may lead to inflammation, invasion, cytokine alteration, increased oxidative stress, and impaired cell viability and proliferation, culminating in endometriosis. Nevertheless, future research is important to curb the progression and development of endometriosis, and strategies for prevention, diagnosis, and treatment are a priority. In this regard, public policies and recommendations to reduce exposure to phthalates and other endocrine disruptors should be promptly implemented.

N-Myc and STAT Interactor is an Endometriosis Suppressor

In patients with endometriosis, refluxed endometrial fragments evade host immunosurveillance, developing into endometriotic lesions. However, the mechanisms underlying this evasion have not been fully elucidated. N-Myc and STAT Interactor (NMI) have been identified as key players in host immunosurveillance, including interferon (IFN)-induced cell death signaling pathways. NMI levels are markedly reduced in the stromal cells of human endometriotic lesions due to modulation by the Estrogen Receptor beta/Histone Deacetylase 8 axis. Knocking down NMI in immortalized human endometrial stromal cells (IHESCs) led to elevated RNA levels of genes involved in cell-to-cell adhesion and extracellular matrix signaling following IFNA treatment. Furthermore, NMI knockdown inhibited IFN-regulated canonical signaling pathways, such as apoptosis mediated by Interferon Stimulated Gene Factor 3 and necroptosis upon IFNA treatment. In contrast, NMI knockdown with IFNA treatment activated non-canonical IFN-regulated signaling pathways that promote proliferation, including β-Catenin and AKT signaling. Moreover, NMI knockdown in IHESCs stimulated ectopic lesions' growth in mouse endometriosis models. Therefore, NMI is a novel endometriosis suppressor, enhancing apoptosis and inhibiting proliferation and cell adhesion of endometrial cells upon IFN exposure.

Predictive Role of Progesterone Levels for IVF Outcome in Different Phases of Controlled Ovarian Stimulation for Patients With and Without Endometriosis: Expert View

The study aimed to review the role of basal, trigger, and aspiration day progesterone levels (PLs) as predictors of in vitro fertilization (IVF) success for patients with and without endometriosis. A non-systematic review was conducted by searching papers published in English during the period of 1990-2023 in MEDLINE and PubMed, Embase, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register), and Web of Science. The most widely used IVF predictor success was the trigger day progesterone serum level. Many studies utilize the threshold level of 1.5-2.0 ng/ml. However, the predictive power of only progesterone level failed to show high sensitivity and specificity. Contrary, progesterone level on the trigger day combined with the number of mature retrieved oocytes had the highest predictive power. High baseline progesterone level was associated with poor IVF outcomes. Research on progesterone and IVF success in patients with endometriosis is limited but indicates that endometriosis patients seem to benefit from higher progesterone concentrations (≥ 37.1 ng/ml) in IVF cycles. Currently, there is limited data for a definitive insight into the mportance of progesterone in the estimation of IVF success. Nonetheless, this summarized evidence could serve as up-to-date guidance for the role of progesterone in the prediction of IVF outcomes, both in patients with and without endometriosis.

Genetic Links between Endometriosis and Endometriosis-Associated Ovarian Cancer-A Narrative Review (Endometriosis-Associated Cancer)

Endometriosis is a frequent, estrogen-dependent, chronic disease, characterized by the presence of endometrial glands and stroma outside of the uterine cavity. Although it is not considered a precursor of cancer, endometriosis is associated with ovarian cancer. In this review, we summarized the evidence that clear-cell and endometrioid ovarian carcinomas (endometriosis-associated ovarian carcinoma-EAOC) may arise in endometriosis. The most frequent genomic alterations in these carcinomas are mutations in the AT-rich interaction domain containing protein 1A (ARID1A) gene, a subunit of the SWI/SNF chromatin remodeling complex, and alterations in phosphatidylinositol 3-kinase (PI3K) which frequently coexist. Recent studies have also suggested the simultaneous role of the PTEN tumor-suppressor gene in the early malignant transformation of endometriosis and the contribution of deficient MMR (mismatch repair) protein status in the pathogenesis of EAOC. In addition to activating and inactivating mutations in cancer driver genes, the complex pathogenesis of EAOC involves multiple other mechanisms such as the modulation of cancer driver genes via the transcriptional and post-translational (miRNA) modulation of cancer driver genes and the interplay with the inflammatory tissue microenvironment. This knowledge is being translated into the clinical management of endometriosis and EAOC. This includes the identification of the new biomarkers predictive of the risk of endometriosis and cancer, and it will shape the precision oncology treatment of EAOC.

N-Myc and STAT Interactor is an endometriosis suppressor

In patients with endometriosis, refluxed endometrial fragments evade host immunosurveillance, developing into endometriotic lesions. However, the mechanisms underlying this evasion have not been fully elucidated. N-Myc and STAT Interactor (NMI) have been identified as key players in host immunosurveillance, including interferon (IFN)-induced cell death signaling pathways. NMI levels are markedly reduced in the stromal cells of human endometriotic lesions due to modulation by the Estrogen Receptor beta/Histone Deacetylase 8 axis. Knocking down NMI in immortalized human endometrial stromal cells (IHESCs) led to elevated RNA levels of genes involved in cell-to-cell adhesion and extracellular matrix signaling following IFNA treatment. Furthermore, NMI knockdown inhibited IFN-regulated canonical signaling pathways, such as apoptosis mediated by Interferon Stimulated Gene Factor 3, and necroptosis upon IFNA treatment. In contrast, NMI knockdown with IFNA treatment activated non-canonical IFN-regulated signaling pathways that promote proliferation, including β-Catenin and AKT signaling. Moreover, NMI knockdown in IHESCs stimulated ectopic lesions' growth in mouse endometriosis models. Therefore, NMI is a novel endometriosis suppressor, enhancing apoptosis and inhibiting proliferation and cell adhesion of endometrial cells upon IFN exposure.

Postmenopausal endometriosis: a challenging condition beyond menopause

IMPORTANCE AND OBJECTIVE

Postmenopausal endometriosis is a complex condition that challenges the conventional belief that endometriosis resolves with menopause. Despite the cessation of menstruation, a subset of women continues to experience or develop endometriosis-related symptoms during the postmenopausal period. Thus, this review aimed to shed light on postmenopausal endometriosis, exploring its clinical features, diagnostic considerations, management approaches, and the potential impact on women's health.

METHODS

PubMed/Medline, Scopus, and Web of Science databases were used for the research, with only articles in English language, using the following terms: "postmenopausal endometriosis," "menopause," "management," "treatment," and "quality of life," from inception to 2023.

DISCUSSION AND CONCLUSION

The clinical features of postmenopausal endometriosis include persistent or recurrent pelvic pain, dyspareunia, bowel, or urinary symptoms and, occasionally, abnormal vaginal bleeding. The absence of menstrual cycles presents a diagnostic challenge, as the traditional diagnostic criteria for endometriosis rely on menstrual patterns. Visual cues may be less evident, and the symptoms often overlap with other gynecological conditions, necessitating a thorough evaluation to differentiate postmenopausal endometriosis from other potential causes. Management approaches for postmenopausal endometriosis encompass surgical intervention, hormonal therapies, pain management, and individualized care. Postmenopausal endometriosis significantly impacts the quality of life, sexual health, and long-term well-being of women. Understanding the clinical features, diagnostic challenges, and management approaches of postmenopausal endometriosis is crucial for healthcare professionals to provide effective care and to improve the quality of life of women affected by this condition.

A Psychological Point of View on Endometriosis and Quality of Life: A Narrative Review

Endometriosis is a chronic gynecological disorder with a multifactorial etiology that has not yet been fully elucidated. What is known, however, are the pathological tissue dynamics that lead to the complex symptoms that women suffer from. The known symptoms are mainly fertility problems and pain. Both dimensions have an impact that varies from case to case, but that is certainly decisive concerning a woman's health, specifically by affecting the overall quality of life (QoL). In this publication, we will deal with the descriptive aspects of endometriosis's pathology and then present a review of the aspects impacting QoL and their psycho-social consequences. Finally, the experience of pain in the context of the mind-brain-body relationship will be discussed, describing the complexity of this dimension and emphasizing the importance of a multi-professional approach that considers the relevance of the contribution that a psychotherapy intervention based on up-to-date neurobiological models can make for women with endometriosis. A review of the literature and current knowledge on the neural and psychological aspects of pain lead to the conclusion that it is of the utmost importance to provide informed psychological support, alongside medical treatments and sexual counseling, to patients with endometriosis.

Adenomyotic Lesions Are Induced in the Mouse Uterus after Exposure to NSAID and EE2 Mixtures at Environmental Doses

The aim of this study was to assess the long-term effect of exposure to environmentally relevant doses of non-steroidal anti-inflammatory drugs (NSAIDs; ibuprofen, and diclofenac) and 17β-ethinylestradiol (EE2) on the mouse uterus. NSAID-EE2 mixtures were administered in the drinking water from gestational day 8 until 8 weeks post-birth (i.e., during embryo development, lactation, puberty, and sexual maturity). The incidence of adenomyosis lesions (presence of endometrial glands in the inner myometrium) increased up to 60% in the uterus of 8-week-old exposed females (F1) and to 85% in F2 females (exposed father). Histological analysis revealed aberrant proliferation and apoptosis, vacuolization of epithelial cells, and increased incidence of abnormal glands in the luminal and glandular epithelium in F1 and F2 uteri. Moreover, myofibroblast proportion (alpha-smooth muscle actin (α-SMA) expression analysis) and collagen expression (Picrosirius red stain; a fibrosis hallmark) were increased in F1 and F2 endometrium. Connexin-43 was aberrantly distributed in the endometrial stroma and glands of F1 and F2 uteri. Conversely, uterine 17β-estradiol and progesterone levels were not affected in F1 and F2 females. These findings demonstrated that in mice, chronic exposure to NSAID and EE2 mixtures at environmental doses intergenerationally affects uterine physiology, particularly the endometrium. It may serve as a model to study the pathophysiology of human adenomyosis.

The adverse role of endocrine disrupting chemicals in the reproductive system

Reproductive system diseases pose prominent threats to human physical and mental well-being. Besides being influenced by genetic material regulation and changes in lifestyle, the occurrence of these diseases is closely connected to exposure to harmful substances in the environment. Endocrine disrupting chemicals (EDCs), characterized by hormone-like effects, have a wide range of influences on the reproductive system. EDCs are ubiquitous in the natural environment and are present in a wide range of industrial and everyday products. Currently, thousands of chemicals have been reported to exhibit endocrine effects, and this number is likely to increase as the testing for potential EDCs has not been consistently required, and obtaining data has been limited, partly due to the long latency of many diseases. The ability to avoid exposure to EDCs, especially those of artificially synthesized origin, is increasingly challenging. While EDCs can be divided into persistent and non-persistent depending on their degree of degradation, due to the recent uptick in research studies in this area, we have chosen to focus on the research pertaining to the detrimental effects on reproductive health of exposure to several EDCs that are widely encountered in daily life over the past six years, specifically bisphenol A (BPA), phthalates (PAEs), polychlorinated biphenyls (PCBs), parabens, pesticides, heavy metals, and so on. By focusing on the impact of EDCs on the hypothalamic-pituitary-gonadal (HPG) axis, which leads to the occurrence and development of reproductive system diseases, this review aims to provide new insights into the molecular mechanisms of EDCs' damage to human health and to encourage further in-depth research to clarify the potentially harmful effects of EDC exposure through various other mechanisms. Ultimately, it offers a scientific basis to enhance EDCs risk management, an endeavor of significant scientific and societal importance for safeguarding reproductive health.

How Can Selected Dietary Ingredients Influence the Development and Progression of Endometriosis?

Endometriosis is a chronic, hormone-dependent disease characterized by the presence of endometrial tissue in ectopic locations. Since the treatment options for this disease are still limited, and the cure rate is unsatisfactory, the search for ways to treat symptoms and modify the course of the disease is of key importance in improving the quality of life of patients with endometriosis. So far, the literature has shown that nutrition can influence endometriosis through hormonal modification and altering the inflammatory or oxidative response. Since the importance of nutrition in this disease is still a subject of scientific research, we aimed to summarize the current knowledge on the role of dietary modifications in endometriosis. Our review showed that nutrients with anti-inflammatory and antioxidant properties, including most vitamins and several trace elements, may influence the pathogenesis of endometriosis and can be considered as the nutrients preventing the development of endometriosis. However, despite the many discoveries described in this review, further interdisciplinary research on this topic seems to be extremely important, as in the future, it may result in the development of personalized therapies supporting the treatment of endometriosis.

Epidemiology of endometriosis in Ukraine: results a multicenter study (2019-2021)

OBJECTIVE

Aim: To estimate the prevalence and incidence of endometriosis, and to evaluate risk factors associated with endometriosis in Ukraine.

PATIENTS AND METHODS

Materials and Methods: The multicenter cohort study was performed partly as a cross-sectional study to estimate occurrence of endometriosis, partly as a case-control study to look for factors associated with endometriosis. The study was carried out during the period from January 1st, 2019 to December 31st, 2021.This study included adolescent girls and adult women from 15 Ukrainian regions.

RESULTS

Results: Among 15,458 patients, 4,397 (28.4%) endometriosis were observed. Of all endometriosis cases, 48.5% were peritoneal/superf i cial endometriosis (SPE), 34.6% were ovarian endometriotic cyst/endometrioma (OMA), and 16.9% were deep inf i ltrating endometriosis (DIE). The prevalence of the three types of endometriosis was: SPE, 13.8%; OMA, 9.8%; and DIE, 4.8%. The factors associated with an increased risk for endometriosis include age 23-32 years, parity (small number of births), age of fi rst sexual intercourse <20 years, history of healthcare-associated infection after gynecological surgery (pelvic abscess or cellulitis, salpingitis and oophoritis), history of infertility, early menarche (before the age of 11), dysmenorrhea, dyspareunia, pelvic pain, intermenstrual bleeding, heavy uterine bleeding and dysmenorrhea, and heavy uterine bleeding.

CONCLUSION

Conclusions: Endometriosis is a common gynecological disease in Ukraine and the relative frequency of dif f erent types of endometriosis: the most common were ovarian and peritoneal endometriosis. Healthcare services and public health strategies need to be strengthened to ensure timely endometriosis diagnosis in adolescent girls and adult women and treatment.

Reproductive Immunology and Pregnancy 3.0

This Special Issue, the third dedicated to reproductive immunology and pregnancy, is another review of the latest trends in research topics in this field [...].

Assessment of MMP14, CAV2, CLU and SPARCL1 expression profiles in endometriosis

Endometriotic cells exhibit a notable degree of invasiveness and some characteristics of tissue remodeling underlying lesion formation. In this regard, do matrix metalloproteinases 14 (MMP14) and other related genes such as SPARC-like protein 1 (SPARCL1), caveolin 2 (CAV2), and clusterin (CLU) exert any significant influence in the processes of endometriosis development and pathophysiology is not apparent. We aim to assess whether these genes could serve as potential diagnostic biomarkers in endometriosis. Microarray-based gene expression analysis was performed on total RNA extracted from endometriotic tissue samples treated with and without gonadotropin-releasing hormone agonist (GnRHa). The GnRHa untreated patients were considered the control group. The validation of genes was performed using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR analysis showed significant downregulation in the expression of MMP14 (p = 0.024), CAV2 (p = 0.017), and upregulation of CLU (p = 0.005) in endometriosis patients treated with GnRHa. SPARCL1 did not show any significant (p = 0.30) change in the expression compared to the control group. These data have the potential to contribute to the comprehension of the molecular pathways implicated in the remodeling of the extracellular matrix, which is a vital step for the physiology of the endometrium. Based on the result, it is concluded that changes in the expression of MMP14, CAV2, and CLU post-treatment imply their role in the pathophysiology of endometriosis and may serve as a potential diagnostic biomarker of endometriosis in response to GnRHa treatment in patients with ovarian endometrioma.

Neutrophil gelatinase-associated lipocalin serum level: A potential noninvasive biomarker of endometriosis?

Neutrophil gelatinase-associated lipocalin (NGAL, also known as lipocalin-2) is an acute-phase protein expressed in many tissues and plays a role in cell proliferation, regulation, and epithelial-mesenchymal transformation. Therefore, this study aimed to investigate serum NGAL levels and endometrioma tissue expression in women with endometriosis. This cross-sectional study was conducted at a university hospital. The endometrioma group included 36 women who underwent ovarian cystectomy for endometrioma, which was compared with a control group (n = 36) of women who underwent ovarian cystectomy due to benign persistent cysts (follicle cyst, theca lutein cyst, and serous cystadenoma). NGAL levels were analyzed using both serum enzyme-linked immunosorbent assay analysis and immunohistochemical tissue staining. Serum C-reactive protein and CA-125 levels were also evaluated. NGAL serum levels were significantly higher in the endometrioma group than in the control group (P < .05). C-reactive protein and CA-125 levels were also significantly higher in the endometrioma group (P < .05) and were correlated with NGAL levels. Immunohistochemical staining for NGAL was also higher in the endometrioma group (P < .001). NGAL may be considered a potential noninvasive biomarker of endometriosis.

An interplay of Progesterone, Leukemia Inhibitor Factor and Interleukin-6 in the window of implantation; Impact on fertility

BACKGROUND

The process of implantation is crucial for the initiation of conception and hence fertility. In addition to a number of factors, it is regulated by a cross talk of gonadotrophins [Luteinizing Hormone (LH), Follicle Stimulatory Hormone (FSH)], ovarian steroids [Estrogen (Et), Progesterone (Pt)] and cytokines [Leukemia inhibitory factor (LIF) and Interleukin 6 (IL6)]. These biomarkers are chief players of implantation.

OBJECTIVE

We aimed to explore the role of gonadotrophins (LH, FSH, LH/FSH ratio), ovarian steroids (Et, Pt) and cytokines (LIF, IL6) in the implantation process. This aim was achieved by comparing these hormones and cytokines in the fertile and infertile groups [Polycystic ovaries (PCOs), endometriosis, unexplained infertility (Uex-IF)] and finding their association in all study groups.

METHODS

A case control study conducted from October 2020-March 2023. A total of 135 infertile women (with PCOs, Uex-IF, and endometriosis) and 177 fertile women (matched for age and BMI) were selected. Levels of 'Et', 'Pt', 'LIF' and, 'IL6' were estimated using Enzyme Linked Immunosorbent Assay (ELISA). LH and FSH values were obtained from hospital desk records. The Independent Student'st-test was used to compare fertile and infertile groups. One-way ANOVA test was used to compare more than two groups, and Pearson's chi-square (χ2) test was employed to compare percentages of variables. Pearson correlation analysis was performed to assess the associations and correlations. A p value < 0.05 was considered statistically significant.

RESULTS

Significantly higher levels of LIF and IL6 were observed in fertile women compared to infertile women. Pt levels were significantly greater in the fertile group than in the infertile group. The FSH/LH ratio was significantly higher in the fertile group. Among infertile women, PCOs (71%) and Uex-IF (91%) exhibited lower Pt levels than the fertile controls (p < 0.01), but these levels remained within the reference range (RR). Among the fertile group (81%), levels of LIF within the RR were significantly higher compared to those with Uex-IF (49%) and females with endometriosis (37%). Moreover, the highest number of participants (57%) with Uex-IF exhibited IL6 levels significantly below the RR in comparison to the fertile group and infertile groups (PCOS and endometriosis). However, lower levels of IL6 were observed in women with Uex-IF. In the control group, LIF exhibited a significant positive correlation with IL6 (r = 0.370), Pt (r = 0.496), Et (r = 0.403), and LH (r = 0.428). Among women with PCOs, LIF showed a significant positive correlation with IL6 (r = 0.443), Pt (r = 0.607), and LH (r = 0.472). In cases of Uex-IF, LIF demonstrated a significant positive correlation with IL6 (r = 0.727). Females with endometriosis displayed a significant positive correlation between LIF and IL6 (r = 0.535) as well as Pt (r = 0.605). In fertile women, a positive correlation was observed between LH and IL6 (r = 0.197, p = 0.009), LIF (r = 0.428, p = 0.000), Pt (r = 0.238, p = 0.001), and Et (r = 0.356, p = 0.000). Furthermore, a positive correlation was found between LH and LIF (r = 0.472, p = 0.000) in women with PCOs.

CONCLUSION

Elevated levels of Pt were found to increase the production of LIF in fertile females. However, infertile females with PCOs and Uex-IF exhibited deficient levels of Pt, supporting its role as a biomarker for successful implantation in infertile women. These females showed decreased levels of gonadotropins as well as reduced LH/FSH ratio and diminished secretion of receptivity marker LIF, in addition to reduced Pt secretion. This suggests that reduced gonadotropin levels contribute to a lower LH/FSH ratio, resulting in decreased Pt secretion and ultimately leading to low levels of LIF, thereby causing impaired implantation in women with PCOs and Uex-IF. The exploration of low levels of LIF in patients with endometriosis requires further investigation. The significantly low levels of IL6 in the Uex-IF group elucidate the role of this cytokine in association with decreased Pt and LIF synthesis within this group.

Retained Intrauterine Fetal Bone Fragments Causing Secondary Infertility: A Review

Retained intrauterine fetal bone fragments are emerging as a potential yet often overlooked cause of secondary infertility, posing significant challenges for couples who have previously experienced successful pregnancies. This review article explores the association between retained fetal bone fragments and secondary infertility by delving into their impact on fertility, pregnancy outcomes, and diagnostic challenges. The review highlights the underlying mechanisms of fragment retention, including immune response and inflammation, and their detrimental effects on endometrial receptivity and implantation. The diagnostic difficulties and importance of specialized imaging techniques like hysteroscopy for accurate diagnosis are also discussed. The article also provides insights into available treatment options, such as medical management and surgical interventions, focusing on hysteroscopy as the gold standard for diagnosis and treatment. The implications for clinical practice emphasize early diagnosis and intervention to improve fertility outcomes and reduce the emotional burden of secondary infertility. Furthermore, the review discusses preventive strategies and the potential for future research to refine diagnostic methods and explore novel treatments. By recognizing and addressing the impact of retained fetal bone fragments, this review aims to enhance the understanding and management of this condition, providing valuable support to couples seeking to overcome the challenges of secondary infertility on their journey toward parenthood.

Puzzling Out the Genetic Architecture of Endometriosis: Whole-Exome Sequencing and Novel Candidate Gene Identification in a Deeply Clinically Characterised Cohort

Endometriosis (EM) is a common multifactorial gynaecological disorder. Although Genome-Wide Association Studies have largely been employed, the current knowledge of the genetic mechanisms underlying EM is far from complete, and other approaches are needed. To this purpose, whole-exome sequencing (WES) was performed on a deeply characterised cohort of 80 EM patients aimed at the identification of rare and damaging variants within 46 EM-associated genes and novel candidates. WES analysis detected 63 rare, predicted, and damaging heterozygous variants within 24 genes in 63% of the EM patients. In particular, (1) a total of 43% of patients carried variants within 13 recurrent genes (FCRL3, LAMA5, SYNE1, SYNE2, GREB1, MAP3K4, C3, MMP3, MMP9, TYK2, VEGFA, VEZT, RHOJ); (2) a total of 8.8% carried private variants within eight genes (KAZN, IL18, WT1, CYP19A1, IL1A, IL2RB, LILRB2, ZNF366); (3) a total of 24% carried variants within three novel candidates (ABCA13, NEB, CSMD1). Finally, to deepen the polygenic architecture of EM, a comprehensive evaluation of the analysed genes was performed, revealing a higher burden (p < 0.05) of genes harbouring rare and damaging variants in the EM patients than in the controls. These results highlight new insights into EM genetics, allowing for the definition of novel genotype-phenotype correlations, thereby contributing, in a long-term perspective, to the development of personalised care for EM patients.