The inheritance of groin hernia: a systematic review

Global, regional, and national burden of inguinal, femoral, and abdominal hernias: a systematic analysis of prevalence, incidence, deaths, and DALYs with projections to 2030

BACKGROUND

Hernias, particularly inguinal, femoral, and abdominal, present a global health challenge. While the Global Burden of Disease (GBD) study offers insights, systematic analyses of hernias remain limited. This research utilizes the GBD dataset to explore hernia implications, combining current statistics with 2030 projections and frontier analysis.

METHODS

We analyzed data from the 2019 GBD Study, focusing on hernia-related metrics: prevalence, incidence, deaths, and disability-adjusted life years (DALYs) across 204 countries, grouped into 21 GBD regions by the SDI (SDI). Data analysis incorporated relative change calculations, Annual Percentage Change (APC), Average Annual Percentage Change (AAPC), and Joinpoint Regression Analysis. The study also employed frontier analysis and the Bayesian Age-Period-Cohort model for trend prediction up to 2030. Analyses utilized R version 4.2.3.

RESULTS

From 1990 to 2019, global hernia cases surged by 36%, reaching over 32.5 million, even as age-standardized rates declined. A similar pattern was seen in mortality and DALYs, with absolute figures rising but age-standardized rates decreasing. Gender data between 1990 and 2020 showed consistent male dominance in hernia prevalence, even as rates for both genders fell. Regionally, Andean Latin America had the highest prevalence, with Qatar and Bulgaria noting significant increases and decreases, respectively. Frontier analyses across 204 countries linked higher SDIs with reduced hernia prevalence. Yet, some high SDI countries, like Qatar and the UK, deviated unexpectedly. Predictions up to 2030 anticipate increasing hernia prevalence, predominantly in males, while death rates are expected to decline. DALYs, after declining, are stabilizing.

CONCLUSIONS

Our analysis reveals a complex interplay between socio-demographic factors and hernia trends, emphasizing the need for targeted healthcare interventions. Despite advancements, vigilance and continuous research are essential for optimal hernia management globally.

The inheritance of groin hernias: an updated systematic review with meta-analyses

PURPOSE

The aim of this systematic review was to assess the inheritance of groin hernias.

METHODS

The primary outcome was to assess the inheritance based on the family history of groin hernias. We included studies that reported family history in patients with groin hernias, assessed the development of groin hernias in patients with a positive family history, or assessed the development of groin hernias in twins. Searches were conducted in PubMed, EMBASE, and Cochrane CENTRAL in November 2021. Results were synthesized narratively and with meta-analyses.

RESULTS

Twenty-two studies with unique participants were included. While two twin studies did not show convincing results of a genetic origin in children, database studies with low risk of bias showed that a positive history in parents or siblings increased the risk of inguinal hernia in children, and the risk was highest between mothers and daughters and between sisters. In adults, patients with inguinal hernia had higher odds of having a positive family history compared with patients without groin hernia (odds ratio 5.3, 95% confidence interval 3.3-8.7), and a nationwide study found the highest risk of inguinal hernia repair when a sister had been repaired compared with a brother. This study also found that having a sibling repaired for a groin hernia increased the risk of femoral hernia repair.

CONCLUSION

Despite studies being heterogeneous, there is overwhelming evidence that a positive family history is a risk factor for developing inguinal hernia in both children and adults, seemingly with a pronounced female-female inheritance pattern.

Role of Collagen in the Etiology of Inguinal Hernia Patients: A Case-Control Study

Introduction Technical faults are no longer accepted as the sole reason for recurrence following inguinal hernia (InH) repairs. Medical literature has been studied to find any contributing factors and collagen has emerged as a promising marker. Owing to their long half-lives, it has been found to best reflect the process of scarring, which is central to ensuring the formation of a proper fibrous tissue that incorporates the mesh with the abdominal wall. Methods Sixty participants were divided into two groups. The case group were patients diagnosed with InH and the control group had patients undergoing abdominal surgeries for indications other than abdominal wall hernias. A 0.5x0.5cm specimen of skin and transversalis fascia were biopsied and subsequently stained to determine the amount of collagen I and III. Results Collagen I, collagen III and the ratio of collagen I to III was measured. Collagen I was normal in the skin of both groups but decreased in transversalis fascia of cases. Collagen III was found to be normal in transversalis fascia of both cases and controls, but increased in the skin of cases. Ratio of collagen I to III was decreased in both skin and transversalis fascia of cases. Statistical analysis was carried out using an unpaired t-test, non-parametric Mann-Whitney test, ANOVA and chi-square test. Conclusions Our study has reported that in patients with inguinal hernia, collagen III or immature collagen is increased in skin and collagen I or mature collagen is decreased in the transversalis fascia. The ratio of collagen I/III is decreased in both skin and transversalis fascia.

Shared genetic architecture of hernias: A genome-wide association study with multivariable meta-analysis of multiple hernia phenotypes

Abdominal hernias are common and characterised by the abnormal protrusion of a viscus through the wall of the abdominal cavity. The global incidence is 18.5 million annually and there are limited non-surgical treatments. To improve understanding of common hernia aetiopathology, we performed a six-stage genome-wide association study (GWAS) of 62,637 UK Biobank participants with either single or multiple hernia phenotypes including inguinal, femoral, umbilical and hiatus hernia. Additionally, we performed multivariable meta-analysis with metaUSAT, to allow integration of summary data across traits to generate combined effect estimates. On individual hernia analysis, we identified 3404 variants across 38 genome-wide significant (p < 5×10-8) loci of which 11 are previously unreported. Robust evidence for five shared susceptibility loci was discovered: ZC3H11B, EFEMP1, MHC region, WT1 and CALD1. Combined hernia phenotype analyses with additional multivariable meta-analysis of summary statistics in metaUSAT revealed 28 independent (seven previously unreported) shared susceptibility loci. These clustered in functional categories related to connective tissue and elastic fibre homeostasis. Weighted genetic risk scores also correlated with disease severity suggesting a phenotypic-genotypic severity correlation, an important finding to inform future personalised therapeutic approaches to hernia.

Inguinal Hernia in Nonhuman Primates: From Asymptomatic to Life-Threatening Events

In this study, a review of available data and literature on the epidemiology and anamnesis of inguinal hernias in nonhuman primates, as well as on their clinical evaluation and surgical management, was conducted. Inguinal hernias are assumed to be relatively common in male nonhuman primates. Clinical signs are usually limited to a visible or palpable mass in the groin region without pain or systemic illness. Most hernias contain omentum. Careful monitoring is an acceptable treatment option for those animals. Size, the danger of incarceration, and the presence of strangulation are important factors when considering surgical repair. A strangulated inguinal hernia is an emergency, requiring prompt surgery to avoid tissue necrosis and death. Imaging techniques, as well as computed tomography (CT), ultrasonography, and magnetic resonance imaging (MRI), provide information about the anatomical characteristics of the suspected region, allowing for a diagnosis and treatment. An inguinal hernia repair can be performed with either open surgery or laparoscopic surgery. The hernia repair can be achieved by mesh or suture. Decisions regarding which repair technique to use depend on the surgeon′s skill level and preference. Complication and recurrence rates are generally low. The most common postsurgical complication is a recurrence of the hernia. Contraceptive measures are not indicated in breeders, as there is no known hereditary component, and the presence of hernia does not appear to affect fertility, nor does it predispose to occurrence, recurrence, or incarceration.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

Inguinal hernia – epidemiology, risk factors, treatment methods (literature review)

Inguinal hernias (IH) are widespread in the human population and occur in 27–43 % of men and 3–6 % of women. Many risk factors for IH have been overestimated in the last decade: male gender is considered the leading factor (the ratio between men and women is approximately 1:7), less significant factors are heredity (most significant for women), physical activity (more significant for men), age (peak prevalence of IH occurs at 5 years and 70–80 years), congenital or acquired connective tissue dysplasia, history of prostatectomy, low body mass index.Hernioplasty with the use of synthetic mesh prostheses remains the most popular technique for surgical correction of IH. Performing non-prosthetic hernioplasty is only recommended if mesh prostheses are not available, for example in poor countries. In open hernioplasty using mesh prostheses, different methods are used today: Plug & Patch, Prolene Hernia System, Parietene Progrip, sutureless plastic according to Trabucco, Stoppa, preperitoneal techniques TIPP (trans-inguinal pre-peritoneal), TREPP (transrectus pre-peritoneal), TEP (total extraperitoneal), however, none of them showed significant advantages over the gold standard of open hernioplasty – tensionfree repair according to Liechtenstein.Laparoscopic IH correction is represented by the TAPP (transabdominal preperitoneal) technique, performed through the abdominal cavity, and TEP (total extraperitoneal) – extraperitoneal prosthetic hernioplasty. None of them has a significant advantage in the treatment of IH; therefore, when choosing a treatment method, the surgeon should be guided by the cost of the operation and the level of proficiency in one or another hernioplasty technique.

Identification of fifty-seven novel loci for abdominal wall hernia development and their biological and clinical implications: results from the UK Biobank

PURPOSE

Familial aggregation is known for both hernia development and recurrence. To date, only one genome-wide association study (GWAS) limited to inguinal hernia has been reported that identified four risk-associated loci. We aim to investigate polygenic architecture of abdominal wall hernia development and recurrence.

METHODS

A GWAS was performed in 367,394 subjects from the UK Biobank to investigate the polygenic architecture of abdominal wall hernia subtypes (inguinal, femoral, umbilical, ventral) and identify specific single nucleotide polymorphisms (SNPs) that are associated with their risk. Expression quantitative trait loci (eQTL) analysis was performed to identify genes whose expression levels are associated with these SNPs. A genetic risk score (GRS) was used to assess the cumulative effect of multiple independent risk-associated SNPs on hernia development and recurrence in independent subjects (n = 82,064).

RESULTS

Heritability (h²) was 0.12, 0.06, 0.16, and 0.07 for inguinal, femoral, umbilical, and ventral hernias, respectively. A high-level of genetic correlation (r_g) was found among these subtypes of hernia. We confirmed the aforementioned four loci and identified 57 novel loci (P < 5 × 10^-8), including 55, 3, 5, and 3 loci for inguinal, femoral, umbilical, and ventral hernias, respectively. Significantly different expression levels between risk/reference alleles of SNPs were found for 145 genes, including TGF-β2 and AIG1 for inguinal hernia risk and CALD1 for umbilical hernia risk. Finally, higher GRS deciles were significantly associated with increased risk for hernia development (P_trend = 3.33 × 10^-38) and recurrent hernia repair surgery (P_trend = 3.64 × 10^-14).

CONCLUSION

These novel results have potential biological and clinical implications for hernia management in high-risk patients.

Matrix Metalloproteinases (MMP-2) and Tissue Inhibitors of Metalloproteinases (TIMP-2) in Male Inguinal Hernia Patients at Different Ages

BACKGROUND

Collagen metabolism, controlled by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), might be related to inguinal hernia formation. It was reported that the incidence of inguinal hernia and the recurrence rate after inguinal hernia repair were higher in the elderly. The objective of the research was to assess the amounts of MMP-2 and TIMP-2 in patients at different ages in order to examine the relationship between age and inguinal hernia occurrence.

METHODS

The research included 40 primary inguinal hernia male patients, and four groups were created: 50-59 years old (A group); 60-69 years old (B group); 70-79 years old (C group); 80-89 years old (D group). We got the samples from anterior rectus sheath fascia. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry were applied to estimate the levels of MMP-2 and TIMP-2.

RESULTS

The MMP-2 amounts in C and D group were statistically higher than control group (P < 0.05), and the TIMP-2 levels in C and D group were statistically lower than control group (P < 0.05). We found a positive correlation between age and expression levels of MMP-2 (r = 0.537, P < 0.001; r = 0.569, P < 0.001) and a negative correlation between age and TIMP-2 in inguinal hernia patients (r = - 0.759, P < 0.001; r = - 0.759, P < 0.001).

CONCLUSIONS

Increased MMP-2 and reduced TIMP-2 may have some relationships with higher inguinal hernia incidence of the elderly.

Matrix Metalloproteinases (MMP-2) and Tissue Inhibitors of Metalloproteinases (TIMP-2) in Patients with Inguinal Hernias

BACKGROUND

The development of inguinal hernia might be related with collagen metabolism, which was regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The aim of this study was to evaluate the mRNA and protein expression levels of MMP-2 and TIMP-2 in anterior rectus sheath fascia to investigate the function of them in inguinal hernia formation.

METHODS

The study enrolled 48 primary inguinal hernia patients: 32 participants had indirect inguinal hernia and 16 patients suffered direct inguinal hernia. Specimens were taken from the anterior rectus sheath fascia. The amounts of MMP-2 mRNA and TIMP-2 mRNA were evaluated by real-time fluorescence quantitative polymerase chain reaction (RT-PCR), and immunohistochemistry was performed to assess the protein expression of them.

RESULTS

The mRNA and protein expression levels of MMP-2 in direct group were significantly higher than those of control group (P < 0.05) and indirect group (P < 0.05), while the expression levels of TIMP-2 in direct group were significantly lower than those of control group (P < 0.05) and indirect group (P < 0.05). The ratio of MMP-2 mRNA/TIMP-2 mRNA in direct group was significantly higher than that of control group (P < 0.05) and indirect group (P < 0.05), and the ratio of indirect group was significantly higher than that of control group (P < 0.05). According to receiver operating characteristic (ROC) curve, MMP-2/TIMP-2 can diagnose direct hernia from controls with area under the curve (AUC) of 0.950 and indirect hernia with AUC of 0.730 effectively.

CONCLUSIONS

Elevated level of MMP-2 and decreased level of TIMP-2 may play a role in direct inguinal hernia development. The ratio of MMP-2/TIMP-2 may be useful in identification of direct hernia.

Lower urinary tract symptoms-Benign prostatic hyperplasia may increase the risk of subsequent inguinal hernia in a Taiwanese population: A nationwide population-Based cohort study

Introduction & objectives

It has been suggested that lower urinary tract symptoms—benign prostatic hyperplasia (LUTS-BPH) may be a risk factor for inguinal hernia (IH). The aim of this study was to examine the emergence of a subsequent IH diagnosis in men with and without LUTS-BPH.

Methods

From a database derived from the National Health Insurance Program covering 99% of the population in Taiwan, 22,310 men with LUTS-BPH and 22,310 matched men without LUTS-BPH were identified and followed for IH from 1997 to 2013. Both IH and LUTS-BPH were defined by the ninth revision of the International Classification of Diseases code (ICD9). Subjects younger than 20 years of age and with IH diagnosed before the index date were excluded. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) for subsequent IH, controlling for potential confounders.

Results

Men with and without LUTS-BPH had similar age and comorbidity distributions. During the 10 years of follow-up, 1,303 (5.84%) men with LUTS-BPH and 735 (2.53%) men without LUTS-BPH developed IH. The mean time to IH was 4.02 years and 4.44 years, respectively. After adjusting for age and comorbidities, LUTS-BPH was associated with a two-fold increased risk of IH (HR:2.25, 95% CI = 2.04–2.49).

Conclusion

This nation-wide population-based cohort study showed that LUTS-BPH increased the risk of subsequent IH in a Taiwanese Population.

A network analysis revealed the essential and common downstream proteins related to inguinal hernia

Although more than 1 in 4 men develop symptomatic inguinal hernia during their lifetime, the molecular mechanism behind inguinal hernia remains unknown. Here, we explored the protein-protein interaction network built on known inguinal hernia-causative genes to identify essential and common downstream proteins for inguinal hernia formation. We discovered that PIK3R1, PTPN11, TGFBR1, CDC42, SOS1, and KRAS were the most essential inguinal hernia-causative proteins and UBC, GRB2, CTNNB1, HSP90AA1, CBL, PLCG1, and CRK were listed as the most commonly-involved downstream proteins. In addition, the transmembrane receptor protein tyrosine kinase signaling pathway was the most frequently found inguinal hernia-related pathway. Our in silico approach was able to uncover a novel molecular mechanism underlying inguinal hernia formation by identifying inguinal hernia-related essential proteins and potential common downstream proteins of inguinal hernia-causative proteins.

Do we really need three-dimensional convex inguinal hernia meshes?

PURPOSE

The aim of our study was to assess the anatomical variability in the curvature of the muscles in inguinal region and to determine the necessity of using three-dimensional convex-shape hernia meshes in spite of typical flat ones.

METHODS

The group analyzed consisted of 180 patients with no abnormalities in inguinal region: 30 males and 30 females for every subgroup, with decreased, normal, and increased BMI. For every patient a 3D software model of muscles in the inguinal region was built, based on the segmentation of pelvic CT images and its outer surface determining the shape of the hernia mesh was created. Correlation was tested between the diameter of sphere describing the shape, the height of mesh top, and BMI. The optimal number and diameter of prefabricated hernia mesh set was obtained.

RESULTS

Only a moderate correlation (r = - 0.32) was found between the diameter of sphere and BMI in females and between the height of the mesh top and BMI in females (r = 0.43) and in the whole group of patients (r = 0.33). Accepting fitting error < 5 mm for 62 from 180 cases there was no need to use a convex-shape hernia mesh, for the other cases one of 3 prefabricated hernia meshes with diameters: 854 mm, 434 mm, 298 mm was sufficient.

CONCLUSIONS

For about one-third of patients a commonly used flat hernia mesh is adequate, for the rest of the cases one of 3 convex-shape meshes is sufficient.

Identification of endogenous normalizing genes for expression studies in inguinal ring tissue for scrotal hernias in pigs

The use of reference genes is required for relative quantification in gene expression analysis and since the stability of these genes could be variable depending on the experimental design, it has become indispensable to test the reliability of endogenous genes. Therefore, this study evaluated 10 reference candidate genes in two different experimental conditions in order to obtain stable genes to be used as reference in expression studies related to scrotal hernias in pigs. Two independent experiments were performed: one with 30 days-old MS115 pigs and the other with 60 days-old Landrace pigs. The inguinal ring/canal was collected, frozen and further submitted to real-time PCR analysis (qPCR). For the reference genes stability evaluation, four tools were used: GeNorm in the SLqPCR, BestKeeper, NormFinder and Comparative CT. A general ranking was generated using the BruteAggreg function of R environment. In this study, the RPL19 was one of the most reliable endogenous genes for both experiments. The breed/age effects influenced the expression stability of candidate reference genes evaluated in the inguinal ring of pigs. Therefore, this study reinforces the importance of evaluating the stability of several endogenous genes previous their use, since a consensual set of reference genes is not easily obtained. Here, two sets of genes are recommended: RPL19, RPL32 and H3F3A for 30-days MS115 and PPIA and RPL19 for the 60 days-old Landrace pigs. This is the first study using the inguinal ring tissue and the results can be useful as an indicative for other studies working with gene expression in this tissue.

Increased incidence of inguinal hernia in offspring of female survivors of childhood central nervous system tumors

Female survivors of childhood central nervous system (CNS) tumors experience an increased risk of infertility and various pregnancy complications. We aimed to explore whether the incidence of inguinal hernia could be higher in offspring of female CNS tumor survivors as compared to the general population. Girls who were younger than 15 years of age and diagnosed with CNS tumors between 1958 and 2013 were identified from the Swedish Cancer Registry. By linking with the Swedish Medical Birth Registry, we identified 580 children who were born to mothers of CNS tumor survivors. After 9,662 person-years of follow-up, 23 of them were diagnosed with inguinal hernia, giving an incidence rate (IR) of 2.4 per 1,000 person-years, whereas the IR was 1.2 for the matched controls. Cox regression analysis was used to calculate the hazard ratio (HR) of inguinal hernia. After adjusting for some confounding factors, the incidence of inguinal hernia was significantly increased with an HR of 1.92 (95%CI 1.08-3.41). The association was predominant in offspring whose mothers were diagnosed with CNS tumors at the age of 10 and older, and with CNS tumors located in the brain.

Unilateral Lichtenstein tension-free mesh hernia repair and testicular perfusion: a prospective control study

PURPOSE

Compare testicular perfusion between the herniated and the healthy side pre- and post-surgery.

MATERIALS AND METHODS

Our study was done on patients with unilateral inguinal hernia. A Doppler ultrasound study was performed in the healthy and herniated side before surgery and 3 months after it.

RESULTS

31 patients were included, 74.2% on the right and 25.8% on the left side. When comparing the pre-surgical values of testicular resistance index from the healthy side with those on the herniated side, there was a significant difference at the spermatic cord levels (0.73 ± 0.11 and 0.81 ± 0.13, p = 0.018) and the extra-testicular level (0.66 ± 0.92 and 0.74 ± 0.10, p = 0.032), but a significant difference was not present at the intra-testicular level (0.62 ± 0.07 and 0.65 ± 0.08). Three months after the surgery, there were no statistically significant differences at any of the levels studied.

CONCLUSION

There are no intra-testicular perfusion differences caused by the presence of hernia, nor during post-surgery.

Etiology of Inguinal Hernias: A Comprehensive Review

Background

The etiology of inguinal hernias remains uncertain even though the lifetime risk of developing an inguinal hernia is 27% for men and 3% for women. The aim was to summarize the evidence on hernia etiology, with focus on differences between lateral and medial hernias.

Results

Lateral and medial hernias seem to have common as well as different etiologies. A patent processus vaginalis and increased cumulative mechanical exposure are risk factors for lateral hernias. Patients with medial hernias seem to have a more profoundly altered connective tissue architecture and homeostasis compared with patients with lateral hernias. However, connective tissue alteration may play a role in development of both subtypes. Inguinal hernias have a hereditary component with a complex inheritance pattern, and inguinal hernia susceptible genes have been identified that also are involved in connective tissue homeostasis.

Conclusion

The etiology of lateral and medial hernias are at least partly different, but the final explanations are still lacking on certain areas. Further investigations of inguinal hernia genes may explain the altered connective tissue observed in patients with inguinal hernias. The precise mechanisms why processus vaginalis fails to obliterate in certain patients should also be clarified. Not all patients with a patent processus vaginalis develop a lateral hernia, but increased intraabdominal pressure appears to be a contributing factor.

Familial clustering and risk of groin hernia in children

Background

The hypothesis was that groin hernias are hereditary. This study was undertaken to establish the degree of familial clustering of groin hernias on a nationwide scale.

Methods

A register‐based cohort was created consisting of all children in Denmark whose parents were born in 1970 or later by the use of the Danish Civil Registration System. Within this cohort, all groin hernia operations were identified. To establish the risk estimates associated with a positive family history of groin hernia operation, information on groin hernia operations in fathers, mothers and siblings was also assessed.

Results

In the cohort of 408 381 persons, a total of 4966 were operated on for groin hernia (incidence rate 2·12 per 1000 person‐years at risk). A person with a mother who had undergone surgery for a groin hernia had an increased risk of 2·89 (95 per cent c.i. 2·48 to 3·34) of having a groin hernia operation; a person with a father operated on for a groin hernia had an increased risk of 1·75 (1·58 to 1·94); and a person with a sibling operated on for a groin hernia had an increased risk of 2·54 (2·17 to 2·96). The strongest association was seen between mothers who had been operated on for groin hernia and their daughters (increased risk 6·01, 95 per cent c.i. 4·53 to 7·80), compared with the risk in girls who did not have a mother who had undergone surgery for groin hernia.

Conclusion

Groin hernias are clustered in families, with the strongest relationship seen between mothers and their daughters.

Whole-exome sequencing identifies a potential TTN mutation in a multiplex family with inguinal hernia

Purpose

Inguinal hernia repair is one of the most common procedures in general surgery. Males are seven times more likely than females to develop a hernia and have a 27 % lifetime ‘risk’ of inguinal hernia repair. Several studies have demonstrated that a positive family history is an important risk factor for the development of primary inguinal hernia, which indicates that genetic factors may play important roles in the etiology of the disease. So far, the contribution of genetic factors and underlying mechanisms for inguinal hernia remain largely unknown. The aim of this study was to investigate a multiplex Estonian family with inguinal hernia across four generations.

Methods

The whole-exome sequencing was carried out in three affected family members and subsequent mutation screening using Sanger sequencing was performed in ten family members (six affected and four unaffected).

Results

Whole-exome sequencing in three affected family members revealed a heterozygous missense mutation c.88880A>C (p.Lys29627Thr; RefSeq NM_001256850.1) in the highly conserved myosin-binding A-band of the TTN gene. Sanger sequencing demonstrated that this mutation cosegregated with the disease in this family and was not present in ethnically matched control subjects.

Conclusion

We report that missense variant in the A-band of TTN is the strongest candidate mutation for autosomal-dominant inguinal hernia with incomplete penetrance.

Electronic supplementary material

The online version of this article (doi:10.1007/s10029-016-1491-9) contains supplementary material, which is available to authorized users.

Abdominal wall hernias-A local manifestation of systemically impaired quality of the extracellular matrix

BACKGROUND

Throughout life, inguinal hernia develops in approximately every fourth man, some of whom develop multiple hernias. If patients at risk of developing multiple hernias could be identified by a serologic biomarker, treatment might be able to be tailored and improved. Evidence suggests that abdominal wall hernia formation is associated with altered collagen metabolism. The aim of this study was to evaluate biomarkers for type IV and V collagen turnover in patients with multiple hernias and control subjects without hernia.

METHODS

Venous blood was collected from 88 men (mean age, 62 years) with a history of more than 3 hernia repairs and 86, age-matched men without hernias. Biomarkers for synthesis of collagen type IV (P4NP) and type V (P5CP) as well as breakdown (C4M and C5M) were measured in serum by validated, solid-phase, competitive assays. Collagen turnover was indicated by the ratio between the biomarker for synthesis and breakdown.

RESULTS

Type IV collagen turnover was 1.4-fold increased in patients with multiple hernias compared to control subjects (P < .001), whereas type V collagen turnover was 1.7-fold decreased (P < .001). Diagnostic power of P5CP was 0.83 (95%C.I.:0.77-0.89), P < .001.

CONCLUSION

Patients with multiple hernias exhibit increased turnover of type IV collagen and a decreased turnover of type V collagen, demonstrating systemically altered collagen turnover. Biomarkers for type V collagen turnover may be used to identify patients at risk for or with multiple hernias.

A genome-wide association study identifies four novel susceptibility loci underlying inguinal hernia

Inguinal hernia repair is one of the most commonly performed operations in the world, yet little is known about the genetic mechanisms that predispose individuals to develop inguinal hernias. We perform a genome-wide association analysis of surgically confirmed inguinal hernias in 72,805 subjects (5,295 cases and 67,510 controls) and confirm top associations in an independent cohort of 92,444 subjects with self-reported hernia repair surgeries (9,701 cases and 82,743 controls). We identify four novel inguinal hernia susceptibility loci in the regions of EFEMP1, WT1, EBF2 and ADAMTS6. Moreover, we observe expression of all four genes in mouse connective tissue and network analyses show an important role for two of these genes (EFEMP1 and WT1) in connective tissue maintenance/homoeostasis. Our findings provide insight into the aetiology of hernia development and highlight genetic pathways for studies of hernia development and its treatment.

Inguinal hernia has high lifetime prevalence, especially in men. This genome-wide association study identifies 4 loci to be associated with inguinal hernia, and shows expression of nearby genes in mouse connective tissues.

Genetic and functional analysis of the TBX3 gene promoter in indirect inguinal hernia

Inguinal hernia is a common developmental disease in children and most cases are indirect inguinal hernia (IIH). Genetic factors have been suggested to play important roles in IIH. Although IIH has been observed in several human syndromes, genetic causes and molecular mechanisms for IIH remain unknown. TBX3 is a member of the T-box family of transcription factors that are essential to the embryonic development. Human studies and animal experiments have demonstrated that TBX3 is required for the development of the heart, limbs, mammary glands and other tissues and organs. TBX3 gene expression has been detected in human fibroblast and tissues of abdominal wall. We speculated that TBX3 may be involved in the IIH formation. Since TBX3 activity is highly dosage-sensitive, a TBX3 gene promoter was genetically and functionally analyzed in IIH patients and ethnic-matched controls in this study. One heterozygous deletion variant (g.4820_4821del) was identified in one IIH patient, but in none of controls. The variant significantly decreased TBX3 gene promoter activities, likely by creating a binding site for sex-determining region Y (SRY), mobility group transcription factor. One heterozygous insertion variant (g.3913_3914ins) was only found in one control, which did not affect TBX3 gene promoter activities. Taken together, TBX3 gene variants may contribute to IIH as a rare risk factor by reducing TBX3 levels.

Two functional sequence variants of the GATA6 gene promoter in patients with indirect inguinal hernia

Inguinal hernia is a common surgical disease, majority of which are indirect inguinal hernia (IIH). A positive family history has indicated that genetic factors play important roles in the IIH development. To date, genetic causes and underlying mechanisms for inguinal hernia remain largely unknown. During the embryonic development, GATA transcription factor 6 (GATA6) plays an essential role. Mutations in GATA6 gene and changed GATA6 levels have been associated with human diseases. As GATA6 acts in a dosage-dependent manner, we speculated that changed GATA6 levels, resulting from DNA sequence variants (DSVs) within the gene regulatory regions, may mediate the IIH development. In this study, the GATA6 gene promoter was genetically and functionally analyzed in IIH patients and ethnic-matched controls. Eleven DNA sequence variants (DSVs), including four SNPs and seven new variants, within the GATA6 gene promoter were identified. Two heterozygous DSVs, g.22168361C>A and g.22169106C>T, were identified in two IIH patients, but in none of controls. In cultured human fibroblast, these DSVs significantly reduced the GATA6 gene promoter activities. In addition, three heterozygous DSVs were only found in three controls. Five DSVs, including four SNPs and one new variant, were found in both IIH patients and controls with similar frequencies. Therefore, the DSVs within the GATA6 gene promoter may contribute to the IIH development as a risk factor by changing the GATA6 levels.

Genetic analysis of the TBX2 gene promoter in indirect inguinal hernia

PURPOSE

Inguinal hernia is a common disease, majority of which are indirect inguinal hernia (IIH). A positive family history indicates that genetic factors play important roles in the IIH development. To date, genetic causes for IIH remain unknown. T-box transcription factor 2 (TBX2) is a major regulator in the morphogenesis and organogenesis. The human TBX2 gene is widely expressed in fetal and adult tissues, including muscle and connective tissues. Therefore, we speculated that altered TBX2 gene expression may be involved in the IIH formation.

METHODS

IIH patients (n = 129) and ethnic-matched healthy subjects (n = 198) were recruited for this study. The human TBX2 gene promoters were generated with PCR and directly sequenced to identify DNA sequence variants (DSVs). Furthermore, biological functions of the DSVs were examined with reporter gene constructs in cultured cells.

RESULTS

Total six DSVs within the TBX2 gene promoter were identified. A heterozygous DSV (g.59476307G>C) was identified in an IIH patient, but in none of controls, which significantly decreased the TBX2 gene promoter activities. Another heterozygous DSV (g.59476704G>C) was only found in one control, which did not affect TBX2 gene promoter activities. Four DSVs, g.59476316C>A (rs73991913), g.59476415T>C (rs1476781), g.59476510G>C (rs4455026) and g.59476892C>T (rs2286524), all of which were single nucleotide polymorphisms, were found in both IIH patients and controls with similar frequencies.

CONCLUSIONS

Our data suggested that the DSV within the TBX2 gene promoter was implicated in the IIH development as a rare cause.

Genetic analysis of the TBX1 gene promoter in indirect inguinal hernia

Inguinal hernia is a common disease, most cases of which are indirect inguinal hernia (IIH). Genetic factors play an important role for inguinal hernia. Increased incidences of inguinal hernia have been reported in patients with 22q11.2 microdeletion syndrome, which is mainly caused by TBX1 gene mutations. Thus, we hypothesized that altered TBX1 gene expression may contribute to IIH development. In this study, the human TBX1 gene promoter was genetically analyzed in children with IIH (n=100) and ethnic-matched controls (n=167). Functions of DNA sequence variants (DSVs) within the TBX1 gene promoter were examined in cultured human fibroblast cells. The results showed that two heterozygous DSVs were found, both of which were single nucleotide polymorphisms. One DSV, g.4248 C>T (rs41298629), was identified in a 2-year-old boy with right-sided IIH, but not in all controls, which significantly decreased TBX1 gene promoter activity. Another DSV, g.4199 C>T (rs41260844), was found in both IIH patients and controls with similar frequencies (P>0.05), which did not affect TBX1 gene promoter activity. Collectively, our data suggested that the DSV within the TBX1 gene promoter may change TBX1 level, contributing to IIH development as a rare risk factor. Underlying molecular mechanisms need to be established.

Shared and nonshared familial susceptibility to surgically treated inguinal hernia, femoral hernia, incisional hernia, epigastric hernia, and umbilical hernia

BACKGROUND

The familial risk of abdominal wall hernia (AWH) is largely unknown. In addition, it is unknown whether inguinal hernia (IH), femoral hernia (FH), incisional hernia (INH), epigastric hernia (EH), and umbilical hernia (UH) share familial susceptibility. The aim of this nationwide study was to determine the familial risks of concordant AWH (same disease in proband and exposed relative) and discordant AWH (different disease in proband and exposed relative).

STUDY DESIGN

Data from the Swedish Multigeneration Register on individuals aged 0 to 78 years were linked to the Swedish hospital discharge register and the Swedish outpatient register for the period from 1964 to 2010. Standardized incidence ratios (SIRs) and 95% CIs for surgically treated IH (n = 209,814 cases), FH (n = 4,576), INH (n = 19,494), EH (n = 8,257), and UH (n = 22,761) were calculated for siblings of individuals with hernia compared with the siblings of unaffected individuals. The procedure was repeated for spouses.

RESULTS

All concordant and most discordant familial sibling risks were increased. Familial concordant SIRs for siblings were IH = 1.97 (95% CI, 1.94-1.99), FH = 3.40 (95% CI, 2.44-4.62), INH = 2.24 (95% CI, 2.04-2.46), EH = 5.57 (95% CI, 4.64-6.64), and UH = 3.61 (95% CI, 3.33-3.91). Concordant familial risks were higher than discordant risks. For example, when the proband sibling had IH, the discordant SIRs were FH = 1.74 (95% CI, 1.61-1.88), INH = 1.22 (95% CI, 1.16-1.28), EH = 1.30 (95% CI, 1.20-1.40), and UH = 1.35 (95% CI, 1.29-1.41). Concordant SIRs for spouses were lower: IH = 1.23 (95% CI, 1.20-1.26), FH = 0.97 (95% CI, 0.64-1.36), INH = 1.56 (95% CI, 1.41-1.71), EH = 1.70 (95% CI, 1.09-2.45), and UH = 1.31 (95% CI, 1.09-1.56).

CONCLUSIONS

Family history of surgically treated AWH is an important risk factor for surgical treatment of AWH. The 5 forms of AWH studied share familial susceptibility, but site-specific familial factors might exist. Several spouse risks were increased, suggesting the possibility of a nongenetic contribution to familial risks.