Biallelic EPCAM deletions induce tissue-specific DNA repair deficiency and cancer predisposition.

We report a case of Mismatch Repair Deficiency (MMRD) caused by germline homozygous EPCAM deletion leading to tissue-specific loss of MSH2. Through the use of patient-derived cells and organoid technologies, we performed stepwise in vitro differentiation of colonic and brain organoids from reprogrammed EPCAMdel iPSC derived from patient fibroblasts. Differentiation of iPSC to epithelial-colonic organoids exhibited continuous increased EPCAM expression and hypermethylation of the MSH2 promoter. This was associated with loss of MSH2 expression, increased mutational burden, MMRD signatures and MS-indel accumulation, the hallmarks of MMRD. In contrast, maturation into brain organoids and examination of blood and fibroblasts failed to show similar processes, preserving MMR proficiency. The combined use of iPSC, organoid technologies and functional genomics analyses highlights the potential of cutting-edge cellular and molecular analysis techniques to define processes controlling tumorigenesis and uncovers a new paradigm of tissue-specific MMRD, which affects the clinical management of these patients.

Quality of life and functional outcome for individuals who underwent very early colectomy for familial adenomatous polyposis.

BACKGROUND: The major manifestation of familial adenomatous polyposis is colorectal adenomas, which, if untreated, lead to colorectal cancer. The impact of IPAA on quality of life in adolescents with familial adenomatous polyposis is favorable. There is a group of children who develop polyps at a younger age requiring earlier colectomy. Little is known about this very young subgroup in relation to bowel function or quality of life. OBJECTIVE: The aim of this study was to investigate the outcome in patients with familial adenomatous polyposis who had colectomy at ≤14 years. DESIGN: A cross-sectional quantitative survey was designed to assess outcome. Standardized validated instruments included bowel/psychosocial functioning and quality of life. RESULTS: Among 1337 patients with familial adenomatous polyposis from 409 kindreds, 4% (n = 59) of patients underwent colectomy at ≤14 years of age. Response rate was 84% (n = 32). The mean age at colectomy was 12 years (SD 2), with a current mean age of 24 years (SD 8.5). Fifty-seven percent of patients reported continence. Of the 43% reporting daytime or nighttime incontinence, the majority are <18 years (86%). Younger participants (currently less than 18 years of age) report more restrictions. Mental health is significantly lower among participants with incontinence. They report higher depression and anxiety symptoms, higher levels of intrusion and avoidance, and inferior mental health. The percentage of those worrying about risk of cancer is significantly higher in the younger group (71% vs 24%). Most patients (n = 24, 75%) have had surveillance endoscopy within the past 2 years. LIMITATIONS: This study is limited by study generalizability, selection bias, and small sample size. CONCLUSIONS: Twelve years after colectomy more than half of the patients have favorable bowel function. The rate of incontinence is high, especially among younger patients who have had a shorter time since surgery. Patients with incontinence reported lower psychosocial functioning, are very concerned about their cancer risk, and experience greater distress. This subgroup would benefit from added psychological interventions to enhance coping with familial adenomatous polyposis and surgery.

Role of video capsule endoscopy in patients with constitutional mismatch repair deficiency (CMMRD) syndrome: report from the International CMMRD Consortium.

BACKGROUND AND STUDY AIMS: Constitutional mismatch repair deficiency (CMMRD) syndrome, also known as biallelic mismatch repair deficiency (BMMRD) syndrome is a rare autosomal-recessive genetic disorder that has a high mortality due to malignancy in childhood and early adulthood. The small bowel phenotype in CMMRD is not well described and surveillance protocols for small bowel cancer have not been well established. This study was conducted to evaluate the usefulness and clinical impact of video capsule endoscopy (VCE) for small bowel surveillance. PATIENTS AND METHODS: We retrospectively reviewed the prospectively maintained International CMMRD Consortium database. Treating physicians were contacted and VCE report data were extracted using a standardized template. RESULTS: Among 58 patients included in the database, 38 VCE reports were collected from 17 patients. Polypoid lesions were first detected on VCE at a median age of 14 years (range: 4 - 17). Of these, 39 % in 7 patients (15/38) showed large polypoid lesions (> 10 mm) or multiple polyps that prompted further investigations. Consequently, three patients were diagnosed with small bowel neoplasia including one patient with adenocarcinoma. Small bowel neoplasia and/or cancer were confirmed histologically in 35 % of the patients (6/17) who had capsule surveillance and the lesions in half of these patients were initially visualized on VCE. Multiple polyps were identified on eight VCEs that were completed on three patients. Ten VCEs (28 %) were incomplete due to slow bowel transit; none required capsule removal. CONCLUSIONS: Small bowel surveillance in patients with CMMRD should be initiated early in life. VCE has the potential to detect polyps; however, small bowel neoplasias are often proximal and can be missed, emphasizing the importance of concurrent surveillance with other modalities. MEETING PRESENTATIONS: Digestive Disease Week 2017 and World Congress of Pediatric Gastroenterology, Hepatology and Nutrition 2016.

Colonic polyps in children and adolescents.

Colonic polyps most commonly present with rectal bleeding in children. The isolated juvenile polyp is the most frequent kind of polyp identified in children. 'Juvenile' refers to the histological type of polyp and not the age of onset of the polyp. Adolescents and adults with multiple juvenile polyps are at a significant risk of intestinal cancer. The challenge for adult and pediatric gastroenterologists is determining the precise risk of colorectal cancer in patients with juvenile polyposis syndrome. Attenuated familial adenamatous polyposis (AFAP) can occur either by a mutation at the extreme ends of the adenomatous polyposis coli gene or by biallelic mutations in the mutY homologue (MYH) gene. The identification of MYH-associated polyposis as an autosomal recessive condition has important implications for screening and management strategies. Adult and pediatric gastroenterologists need to be aware of the underlying inheritance patterns of polyposis syndromes so that patients and their families can be adequately evaluated and managed. Colonic polyps, including isolated juvenile polyps, juvenile polyposis syndrome, FAP, AFAP and MYH-associated polyposis, are discussed in the present review.

Keeping an eye on Crohn's disease: orbital myositis as the presenting symptom.

Episodic periorbital swelling due to presumed orbital inflammation and myositis caused intermittent apparent proptosis and was the presenting symptom of ileocecal Crohn's disease (CD) in a teenage female with a family history of autoimmune disorders and CD. Orbital myositis, a very rare extraintestinal manifestation of inflammatory bowel disease (IBD), likely represents a process of impaired immunoregulation related to the underlying intestinal inflammation. This rare manifestation of IBD simulates the more commonly encountered thyroid orbitopathy (ophthalmopathy), but IBD should be considered if all thyroid tests are negative. It is important to recognize that orbital myositis may be an extraintestinal manifestation of Crohn's disease so that the diagnosis can be made and appropriate therapy commenced.

Family history and molecular features of children, adolescents, and young adults with colorectal carcinoma.

BACKGROUND: Colorectal cancer is extremely rare in childhood. Published case series reporting children and adolescents with colorectal cancer have not focused on the underlying genetic aspects of the tumour or genetic susceptibility of the families. AIMS: We examined a cohort of patients with early onset colorectal cancer to determine whether a specific genetic predisposition could be elucidated. In particular, we focused on whether DNA mismatch repair gene deficiency which causes hereditary non-polyposis colorectal cancer (HNPCC) could be elucidated. METHODS: Patients with colorectal cancer

Adherence of vero cytotoxin-producing Escherichia coli serotype O157:H7 to isolated epithelial cells and brush border membranes in vitro: role of type 1 fimbriae (pili) as a bacterial adhesin expressed by strain CL-49.

Vero cytotoxin-producing Escherichia coli of the serotype O157-:H7 have recently been associated with sporadic cases and outbreaks of hemorrhagic colitis and with the hemolytic-uremic syndrome. E. coli O157:H7 strains adhere to human epithelial cells in tissue culture and to the intestine of orally infected rabbits. To determine whether E. coli O157:H7 adhere to normal post-natal human epithelial cells, we isolated buccal epithelial cells from healthy adult volunteers and isolated ileal enterocytes and colonocytes from histologically normal margins of surgical resection specimens. Apical brush border membranes from the distal ileum and colonocytes of the proximal colon were also prepared from post-weaning rabbits. Binding of five E. coli O157:H7 strains to epithelial cells and brush border membranes was determined by two complementary methods: firstly, under phase contrast microscopy and secondly, by quantitating adherence of radiolabelled bacteria to substrates that were bound to polystyrene microtiter wells. Under incubation conditions used previously to document in vitro adherence of other diarrheagenic E. coli, only the one type-1 fimbriated E. coli O157:H7 strain, designated CL-49, adhered to isolated human and rabbit epithelial cells. In contrast, binding of 4 non-type-1 fimbriated O157:H7 strains could not be demonstrated. Adherence of the fimbriated E. coli O157:H7 strain was saturable and varied with pH and temperature of the incubation medium. Adherence of bacteria to rabbit ileal brush borders was mediated by binding of bacteria to alpha-linked mannosyl residues present on surface glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging to distinguish the type and severity of pediatric inflammatory bowel diseases.

BACKGROUND: The distinction between ulcerative colitis and Crohn's disease is important, because treatment options and clinical course may vary. Magnetic resonance imaging (MRI) allows noninvasive transmural assessment of the intestine and may facilitate differentiation of ulcerative colitis from Crohn's disease. The objective of this prospective study was to determine whether MRI differentiates Crohn's disease from ulcerative colitis in children as effectively as colonoscopy with mucosal biopsies. METHODS: Fifteen patients underwent colonoscopy with biopsies followed by abdominal MRI. The MRI diagnosis, determined by two radiologists independently completing a standardized form was compared with the gastroenterologic diagnosis. RESULTS: After colonoscopy and review of histology, Crohn's disease was diagnosed in nine patients, ulcerative colitis in five, and indeterminate colitis in one, who was excluded from study. Agreement of the MRI diagnosis with the gastroenterologic diagnosis was 4 of 4 (100%) for ulcerative colitis, 4 of 10 (40%) for Crohn's disease considering both radiologists, and 5 of 10 (50%) for Crohn's disease for each radiologist individually. Percentage of enhancement by MRI did not correlate with the severity of inflammation determined at endoscopy among the patients with Crohn's disease (r = -0.3, P = 0.366). There was agreement on severity of inflammation in three of four patients with ulcerative colitis. CONCLUSIONS: Current MRI interpretation of inflammatory bowel disease did not adequately recognize Crohn's disease in children. Therefore, colonoscopy with biopsy remains the most accurate tool for determining the type and severity of inflammatory bowel disease in children and adolescents.

Development of a quality-of-life index for pediatric inflammatory bowel disease: dealing with differences related to age and IBD type.

BACKGROUND: A child- and adolescent-generated IBD quality-of-life index was designed to be descriptive (to be used to assess the overall impact of IBD on individual patients), and evaluative (to be used as an outcome measure in clinical trials). METHODS: Item-generation and item-reduction interviews with 82 patients with IBD aged 8 to 17 years (61 with Crohn's disease, 21 with ulcerative colitis; 36 girls, 45 boys) generated a list of ways in which their lives were affected by IBD. These issues were incorporated into an item-reduction questionnaire, which was administered to 117 patients (87 Crohn's disease, 30 ulcerative colitis). Patients indicated on a visual analog scale how important an item was to them and how often it bothered them. Mean and median importance-plus-frequency scores for each issue were calculated for the entire group and among patients in subgroups according to age and IBD type. RESULTS: Ulcerative colitis and Crohn's disease affect the lives of children and adolescents differently. Bowel symptoms are more troubling and disabling to patients with ulcerative colitis, whereas systemic symptoms and body image concerns are greater for patients with Crohn's disease. The impact of Crohn's disease on ability to function in school and leisure activities is greater. Worries about future health problems and about the effects of IBD on the family are shared. Crohn's disease and ulcerative colitis trigger emotional responses of unfairness and frustration, but anger and embarrassment are more prevalent in ulcerative colitis. Disparities between age groups are fewer and less marked than those between types of IBD. CONCLUSION: In selection of items to be retained in a pediatric IBD quality-of-life measure, the variation in concerns with disease type must be considered. A single index to assess IBD-related quality of life must include items of major importance to one subgroup of patients, even if not important to all. Alternately, a core of common concerns could be supplemented by disease-specific modules, thereby increasing the content validity of the tool for all patients.

Outcome after ileoanal anastomosis in pediatric patients with ulcerative colitis.

BACKGROUND: To review the outcome after restorative proctocolectomy among children and adolescents with ulcerative colitis at a pediatric inflammatory bowel disease center. METHODS: The records of all patients with ulcerative colitis undergoing colectomy and ileoanal anastomosis at The Hospital for Sick Children, Toronto, Canada, were reviewed. Questionnaires concerning functional results were sent to patients with restored transanal defecation. RESULTS: Seventy three patients (mean age, 13.2 years; range, 2.6-18.8 years) underwent ileoanal anastomosis (19 straight ileoanal anastomosis, 41 J pouch, 13 S pouch) between January 1980 and June 1995 and were observed 5.8+/-3.3 years. The ileoanal anastomosis is nonfunctional in 19 (26%) patients. Excision rates according to type of restorative procedure were J pouch, 7% (3 of 41); S pouch, 32% (4 of 13); and straight ileoanal anastomosis, 32% (6 of 19). Failure was usually attributable to intractable diarrhea among patients with straight ileoanal anastomosis but was caused by anastomotic leak or pelvic-perianal sepsis among patients with pouch procedures. Failure rates did not vary with age at ileoanal anastomosis. Among patients retaining ileoanal continuity, continence problems reported in the questionnaire were frequent and tended to be more extreme among younger patients. Overall, 90% of respondents reported satisfaction with the functional outcome of the restorative operation. CONCLUSIONS: The success rate of the ileoanal anastomosis/J-pouch procedure is comparable to that in adult series. The ileoanal anastomosis/J-pouch procedure is the operation of choice for children and adolescents who want ileoanal continuity restored after colectomy for ulcerative colitis.