Identification of 14 novel susceptibility loci for diaphragmatic hernia development and their biological and clinical implications: results from the UK Biobank

Exploring the causal relationship between iron status and subarachnoid hemorrhage based on two sample mendelian randomization

This study investigates the causal association between genetic prediction of iron status and subarachnoid hemorrhage (SAH). A two-sample MR analysis was conducted using genome-wide association study (GWAS) summary data for four iron biomarkers: serum iron, serum ferritin, total iron-binding capacity (TIBC), and transferrin saturation (TSAT). Genetic variants were selected as instrumental variables (IVs) to minimize confounding. Causal estimates were obtained using inverse variance weighting (IVW), MR-Egger, weighted median, and weighted mode methods. Sensitivity analyses, including Cochran's Q-test, MR-Egger regression, MR-PRESSO, and leave-one-out analysis, were performed to assess heterogeneity and pleiotropy. IVW analysis revealed a significant association between increased genetically predicted TIBC and higher SAH risk (OR = 1.71, 95% CI: 1.21-2.41, P = 0.002), while higher TSAT was associated with lower SAH risk (OR = 0.76, 95% CI: 0.62-0.93, P = 0.01). No causal association was found between serum iron, serum ferritin, and SAH. Sensitivity analyses confirmed the robustness of the results, with no evidence of horizontal pleiotropy. However, heterogeneity was detected in serum ferritin, suggesting potential variability in its effect. This MR study provides genetic evidence for the causal relationship between TIBC, TSAT, and SAH risk. These findings highlight the potential role of iron metabolism in SAH pathophysiology, warranting further investigation.

Multi-tissue transcriptome-wide association study identifies novel candidate genes and pleiotropy effects across four abdominal hernia subtypes

Abdominal hernias are caused by the protrusion of an organ or tissue through a weakened abdominal wall. Genome-wide association studies (GWASs) have identified 81 genetic susceptibility loci for different hernia subtypes, with 26 loci associated with more than one hernia type; however, additional work is needed to prioritize causal genes at known GWAS loci, identify novel ones, and characterize shared genetic effects across hernia subtypes. We conduct transcriptome-wide association study (TWAS) analyses of four hernia subtypes (i.e., inguinal, umbilical, ventral, femoral) using GWAS summary statistics from up to 57,291 hernia cases and 436,717 controls of European ancestry. Our TWAS, which leveraged imputed gene expression from 54 tissues, identifies 211 unique genes, of which 85 did not overlap with known hernia-associated loci. We also investigate patterns of pleiotropy and identify four genes (LYPLAL1-AS1, RIMKLBP2, AL513283.1, and EFEMP1) associated with all four hernia subtypes. Our findings enhance understanding of transcriptomic mechanisms through which hernias develop.

Genetic and biologic risk factors associated with hernia formation: A review

BACKGROUND

This systematic review aims to identify genetic and biologic markers associated with abdominal hernia formation.

METHODS

Following PRIMSA-guidelines, we searched PubMed, MEDLINE, Embase, Scopus, and COCHRANE databases.

RESULTS

Of 5946 studies, 65 were selected, excluding parastomal hernias due to insufficient data. For inguinal hernias, five studies unveiled 92 susceptible loci across 66 genes, predominantly linked to immune responses. Eleven studies observed elevated MMP-2 levels, with seven highlighting greater MMP-2 in direct compared to indirect inguinal hernias. One incisional hernia study identified unique gene-expression profiles in 174 genes associated with inflammation and cell-adhesion. In hiatal hernias, several genetic risk loci were identified. For all hernia categories, type I/III collagen ratios diminished.

CONCLUSIONS

Biological markers in inguinal hernias appears consistent. Yet, the genetic predisposition in incisional hernias remains elusive. Further research to elucidate these genetic and biological intricacies can pave the way for more individualized patient care.