UNASSIGNED: @entity29 ( @entity29 ) are complex, @entity74 characterized by chronic relapsing intestinal @entity32 . Although etiology remains largely unknown, recent research has suggested that genetic factors, environment, microbiota, and immune response are involved in the pathogenesis. Epidemiological evidence for a genetic contribution is defined: 15% of @entity1 with @entity30 ( @entity30 ) have an affected family member with @entity8787 , and twin studies for @entity30 have shown 50% concordance in monozygotic twins compared to <10% in dizygotics. The most recent and largest genetic association studies, which employed genome-wide association data for over 75,000 @entity1 and controls, identified 163 susceptibility loci for @entity8787 . More recently, a trans-ethnic analysis, including over 20,000 individuals, identified an additional 38 new @entity8787 loci. Although most cases are correlated with polygenic contribution toward genetic susceptibility, there is a spectrum of rare @entity74 that can contribute to early-onset @entity8787 (before 5   years) or very early onset @entity8787 (before 2   years). Genetic variants that cause these disorders have a wide effect on gene function. These variants are so rare in allele frequency that the genetic signals are not detected in genome-wide association studies of @entity1 with @entity8787 . With recent advances in sequencing techniques, ~50 @entity74 have been identified and associated with @entity8787 -like immunopathology. Monogenic defects have been found to alter intestinal immune homeostasis through many mechanisms. Candidate gene resequencing should be carried out in early-onset @entity1 in clinical practice. The evidence that genetic factors contribute in small part to disease pathogenesis confirms the important role of microbial and environmental factors. Epigenetic factors can mediate interactions between environment and genome. Epigenetic mechanisms could affect development and progression of @entity8787 . Epigenomics is an emerging field, and future studies could provide new insight into the pathogenesis of @entity8787 .

XXXX : Genetics, Epigenetics, and Pathogenesis.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation'] @entity29 :: ('MESH:D015212', 'Disease') :: ['IBDs', 'Inflammatory bowel diseases'] @entity74 :: ('MESH:D030342', 'Disease') :: ['genetic disorders', 'multifactorial disorders'] @entity8787 :: ('MESH:C535541', 'Disease') :: ['IBD'] @entity30 :: ('MESH:D003424', 'Disease') :: ['CD', "Crohn's Disease"]
@entity29 :: (MESH:D015212,Disease) :: ['Inflammatory Bowel Disease']
