Monozygotic twins with Crohn’s disease and ulcerative colitis: a unique case report

Abstract

Background-A large number of monozygotic and dizygotic twin pairs with inflammatory bowel disease have been reported. To date no twin pair has developed phenotypically discordant inflammatory bowel disease. This case report is the first documented occurrence of discordant inflammatory bowel disease occurring in monozygotic twins. Case report-Twenty two year old identical male twins presented within three months of each other with inflammatory bowel disease that proved to be discordant in overall disease type, disease distribution, clinical course, and histopathological findings. Twin 1 developed a severe pancolitis necessitating total colectomy while twin 2 developed a predominantly distal patchy colitis with frequent granulomas, controlled by aminosalicylates. Twin 1 was antineutrophil cytoplasmic antibody (ANCA) negative at the time of testing while twin 2 (Crohn's disease) was ANCA positive. Significantly, the twins possessed the HLA type DR3-DR52-DQ2 previously associated with extensive colitis. Conclusion-This case report confirms the important role played by genetic factors in the development of inflammatory bowel disease. It also highlights the crucial role of undetermined environmental agents in dictating disease expression and phenotype.

Clinical Aspects and Pathophysiology of Inflammatory Bowel Disease

“…The concordance rate among dizygotic twins is 4 to 12% for CD and 0 to 5% for UC, significantly lower than the rates reported among monozygotic twins and of the same order of magnitude as in nontwin siblings. One monozygotictwin pair with one member having UC and the other having CD has been reported (8). However, the overall paucity in the literature of such discordant twin pairs would suggest that similar but distinct genetic factors contribute to disease pathogenesis for these two diseases.…”

Crohn disease: A current perspective on genetics, autophagy and immunity

“…In addition, twin studies for CD have shown approximately 50% concordance in monozygotic twins compared to less than 10% dizygotics. 2 The most widely accepted model is one in which a genetically susceptible host encounters an environmental bacterial or viral agent, triggering a breach of the intestinal epithelial barrier which separates the lumenal contents and microbial flora from the mucosal immune system. This primary event may lead to inflammatory flares in the gut mucosa.…”

Association of ATG16L1 and IRGM genes polymorphisms with inflammatory bowel disease: a meta-analysis approach

“…Although the aetiology of these diseases is not fully understood, there is strong support for a genetic component based on findings of familial aggregation, higher concordance in monozygotic twins and ethnic differences in disease prevalence. 1,2 To date, different genetic studies have shown several genes playing a relevant role in these diseases, including NOD2/CARD15, 3 DGL5, 4 SLC22A4 and SLC22A5, 5,6 TNFSF15, 7,8 NOD1/CARD4 7 and IL23R. 9,10 NOD2/CARD15 is likely to be the major genetic factor contributing to CD.…”