Telehealth Coverage for a Pediatric Gastroenterology Consult Service at a Regional Hospital: An Accepted, Useful, and Sustainable Model of Care.

OBJECTIVE: To evaluate a novel telehealth inpatient pediatric gastroenterology (GI) consult service at a regional children's hospital in regard to acceptance, utility, quality, sustainability, and provider resiliency. STUDY DESIGN: Patients requiring GI care at a regional children's hospital between July 2020 and June 2021 were treated by an in-person or telehealth physician with physician assistant support, randomly assigned based on a weekly preset staffing schedule. A retrospective, multidomain program evaluation was performed based on the RE-AIM (reach, effectiveness, adoption, implementation, and maintenance) and STEM (SPROUT Telehealth Evaluation and Management) frameworks, using statistical analysis to compare the patient cohorts and anonymous surveys to assess provider perceptions. RESULTS: In total, 1051 patient-days of GI care were provided for 348 patients, 17% by telehealth and 83% in-person. There were no significant differences in diagnosis, transfer, or readmission rates between the cohorts. No transfers occurred for reasons other than need to access specialized services not available at the regional hospital. Daily consult workload was slightly greater for telehealth physicians. Primary and consult team providers accepted the practice. The model continued beyond the first year. In total, 75% of local GI physicians reported greater Brief Resilience Scores in the context of shifting 20% of their inpatient call weeks to another campus's physicians. CONCLUSION: Episodic pediatric GI consult service coverage via telehealth at a regional hospital was well accepted, useful, and sustainable, with improved physician resilience and no adverse outcomes seen. Telehealth holds promise for leveraging pediatric subspecialty physicians across hospitals, allowing complex patients to be admitted closer to home while reducing inpatient coverage requirements for smaller physician groups.

Characteristics of Children With Inflammatory Bowel Disease and Coexisting Celiac Disease Seropositivity.

OBJECTIVES: Celiac disease (CeD) autoimmunity and coexisting inflammatory bowel disease (IBD) present a diagnostic dilemma. Our aims were to describe the phenotype of children with IBD and CeD seropositivity and evaluate provider confidence for diagnosing CeD in this population. METHODS: We performed a single-center retrospective cohort study of subjects ≤18 years old with IBD and CeD seropositivity between 2006 and 2020. Subjects were considered to have IBD-CeD if they met CeD diagnosis by serology and histology per North American Society For Pediatric Gastroenterology, Hepatology and Nutrition guidelines and if providers suspected CeD as evaluated by a survey. The IBD-only cohort included seropositive participants that did not meet criteria for CeD. Demographic, histologic, gross endoscopic, and laboratory features were compared using Fisher exact test. RESULTS: Of 475 children with IBD, 8 had concomitant CeD, 5 had tissue transglutaminase (tTG) immunoglobulin A (IgA) > 10x upper limit of normal (ULN, P = 0.006), and 8 had villous atrophy (VA, P = 0.003) when compared with 17 seropositive participants with IBD-only. No children with IBD-CeD had esophageal eosinophilia, duodenal cryptitis, duodenal ulceration, or fecal calprotectin >250 µg/g. Factors that contributed to provider uncertainty for diagnosing CeD in IBD included the absence of VA and intraepithelial lymphocytes, the presence of neutrophilic and eosinophilic duodenitis, diffuse ulceration, elevated inflammatory markers, and immunosuppression therapy. CONCLUSIONS: Diagnosing CeD in children with IBD continues to be challenging. Although high titers of tTG IgA and VA increased provider confidence for diagnosing CeD in IBD, development of evidence-based guidelines are needed. They should better assess the importance of features atypical of concomitant CeD that contribute to uncertainty.

Markers of Hypoxia Correlate with Histologic and Endoscopic Severity of Colitis in Inflammatory Bowel Disease.

BACKGROUND: Inflammation results in significant shifts in tissue metabolism. Recent studies indicate that inflammation and hypoxia occur concomitantly. We examined whether circulating and tissue markers of hypoxia could serve as surrogate indicators of disease severity in adult and pediatric patients with inflammatory bowel disease (IBD). METHODS: Serum and colonic biopsies were obtained from pediatric subjects with active IBD colitis and adult subjects with active and inactive ulcerative colitis, along with healthy non-colitis controls of all ages. Disease activity was evaluated by endoscopy and histopathology. Levels of serum hypoxia markers (macrophage inflammatory protein-3α [MIP-3α], vascular endothelial growth factor [VEGF], and erythropoietin [EPO]) were measured. RESULTS: Children with active IBD colitis had higher levels of serum MIP-3α and VEGF compared to non-colitis controls (p<0.01 and p<0.05, respectively). In adult subjects with endoscopically active ulcerative colitis, serum MIP-3α and EPO were significantly elevated compared to non-colitis controls (both p<0.01). In parallel, analysis of colon tissue MIP-3α mRNA and protein in pediatric subjects revealed increased expression in those with IBD colitis compared to controls (p<0.05 and p<0.01 for mRNA and protein, respectively). Serum MIP-3α and VEGF significantly increased with histology grade. CONCLUSION: Peripheral blood hypoxia markers may be useful indicators of disease activity for pediatric and adult IBD patients.

Cannabis Oil Use by Adolescents and Young Adults With Inflammatory Bowel Disease.

OBJECTIVES: The aim of the study was to describe use of oral or sublingual cannabis oil (CO) by adolescent and young adult patients with inflammatory bowel disease (IBD). METHODS: A descriptive study of IBD patients 13 to 23 years of age seen between January 2015 through December 2017 at Children's Hospital Colorado. Information obtained included chart abstraction, electronic and interview self-report, and serum cannabinoid levels. We compared CO users and cannabis non-users for clinical characteristics and perceptions of risk. Users of CO provided information on routes, patterns, motivations, and perceived benefits and problems with use. RESULTS: The 15 users and 67 non-users were similar for clinical characteristics and pain and appetite scores. 9 of 15 (60%) CO users had used in the past 30 days, an average of 22 ±â€Š9 times; and 4 used daily. A variety of strengths and CBD:THC ratios were reported. Most common perceived effect of use was on sleep quality, nausea, and increase in appetite. Of the 15 users, 6 used only CO and no additional forms of cannabis. Of these 6 CO only users, 5 reported a medical reason for use, most commonly to relieve pain. CONCLUSIONS: Adolescent and young adults with IBD used oral CO and many used other cannabis products as well. Users perceived some medical benefit. Care teams should strive for open communication about use until further information on safety and efficacy becomes available.

Marijuana Use by Adolescents and Young Adults with Inflammatory Bowel Disease.

OBJECTIVE: To evaluate marijuana use by adolescents and young adults with inflammatory bowel disease (IBD). STUDY DESIGN: This descriptive cross-sectional study of patients seen between December 2015 through June 2017 at Children's Hospital Colorado for IBD enrolled patients 13-23 years of age, independent of marijuana use status. Information obtained consisted of chart review, electronic and interview self-report, and serum cannabinoid levels. Marijuana ever-users were compared with never-users for clinical characteristics and perceptions of risk with use; users provided information on routes, patterns, motivations, and perceived benefits and problems with use. RESULTS: Of 99 participants, ever-use was endorsed by 32% (32 of 99) and daily or almost daily use by 9% (9 of 99). Older age was the only characteristic related to endorsing marijuana use. Twenty-nine ever-users completed all questionnaires. After adjusting for age, users were 10.7 times more likely to perceive low risk of harm with regular use (P < .001). At least 1 medical reason for use was endorsed by 57% (17 of 30), most commonly for relief of physical pain (53%, 16 of 30) (2 did not complete all questionnaires). Problems from use were identified by 37% (11 of 30), most commonly craving/strong urge to use. Most common route of use was smoking (83%) followed by edibles (50%), dabbing (40%), and vaping (30%). CONCLUSIONS: Marijuana use by adolescents and young adults with IBD is common and perceived as beneficial. Guidelines for screening, testing, and counseling of marijuana use should be developed for patients with IBD.

Safety and Pharmacokinetic Study of Fidaxomicin in Children With Clostridium difficile-Associated Diarrhea: A Phase 2a Multicenter Clinical Trial.

BACKGROUND: Fidaxomicin is an approved therapy for Clostridium difficile-associated diarrhea (CDAD) in adults. The safety of fidaxomicin in children has not been reported. METHODS: In this study (ClinicalTrials.gov identifier NCT01591863), pediatric patients with CDAD received twice-daily oral fidaxomicin at a dose of 16 mg/kg per day (up to 200 mg) for 10 days in an open-label study. Plasma and fecal samples were collected for pharmacokinetic assessments. The primary outcome measure was safety, which was assessed by adverse-event (AE), laboratory, and physical examination/vital-sign monitoring. Efficacy was determined through early and sustained clinical response rates (clinical response without recurrence of CDAD). RESULTS: The study enrolled 40 patients (11 months to 17 years of age), many with underlying comorbidity, including neoplasm (23.7%), gastrointestinal disorder (78.9%), and history of CDAD (60.5%). Plasma fidaxomicin and OP-1118 (the major fidaxomicin metabolite) 3- to 5-hour postdose concentrations were 0.6 to 87.4 and 2.4 to 882.0 ng/mL, respectively, and no age-related trends were seen. Fecal fidaxomicin concentrations within 24 hours of the last dose averaged 3228 µg/g, and higher concentrations and greater variability in the youngest age group were found. AEs were reported in 73.7% of the patients; most of them were mild (44.7%) to moderate (21.1%) and were considered treatment-related in 15.8% of the patients. Overall, the early clinical response rate was 92.1%. The rate of sustained clinical response (clinical response without recurrence through 28 days after treatment) was 65.8% overall. CONCLUSIONS: Fidaxomicin was well tolerated in children with CDAD and has a pharmacokinetic profile in children similar to that in adults. The clinical response rate was high.

An Atmospheric Pressure Chemical Ionization MS/MS Assay Using Online Extraction for the Analysis of 11 Cannabinoids and Metabolites in Human Plasma and Urine.

BACKGROUND: Although, especially in the United States, there has been a recent surge of legalized cannabis for either recreational or medicinal purposes, surprisingly little is known about clinical dose-response relationships, pharmacodynamic and toxicodynamic effects of cannabinoids such as Δ9-tetrahydrocannabinol (THC). Even less is known about other active cannabinoids. METHODS: To address this knowledge gap, an online extraction, high-performance liquid chromatography coupled with tandem mass spectrometry method for simultaneous quantification of 11 cannabinoids and metabolites including THC, 11-hydroxy-Δ9-tetrahydrocannabinol, 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid, 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid glucuronide (THC-C-gluc), cannabinol, cannabidiol, cannabigerol, cannabidivarin, Δ9-tetrahydrocannabivarin (THCV), and 11-nor-9-carboxy-Δ9-tetrahydrocannabivarin (THCV-COOH) was developed and validated in human urine and plasma. RESULTS: In contrast to atmospheric pressure chemical ionization, electrospray ionization was associated with extensive ion suppression in plasma and urine samples. Thus, the atmospheric pressure chemical ionization assay was validated showing a lower limit of quantification ranging from 0.39 to 3.91 ng/mL depending on study compound and matrix. The upper limit of quantification was 400 ng/mL except for THC-C-gluc with an upper limit of quantification of 2000 ng/mL. The linearity was r > 0.99 for all analyzed calibration curves. Acceptance criteria for intrabatch and interbatch accuracy (85%-115%) and imprecision (<15%) were met for all compounds. In plasma, the only exceptions were THCV (75.3%-121.2% interbatch accuracy) and cannabidivarin (interbatch imprecision, 15.7%-17.2%). In urine, THCV did not meet predefined acceptance criteria for intrabatch accuracy. CONCLUSIONS: This assay allows for monitoring not only THC and its major metabolites but also major cannabinoids that are of interest for marijuana research and clinical practice.

High Incidence of Celiac Disease in a Long-term Study of Adolescents With Susceptibility Genotypes.

BACKGROUND & AIMS: Little is known about the incidence of celiac disease in the general population of children in the United States. We aimed to estimate the cumulative incidence of celiac disease in adolescents born in the Denver metropolitan area. METHODS: We collected data on HLA-DR, DQ genotypes of 31,766 infants, born from 1993 through 2004 at St. Joseph's Hospital in Denver, from the Diabetes Autoimmunity Study in the Young. Subjects with susceptibility genotypes for celiac disease and type 1 diabetes were followed up for up to 20 years for development of tissue transglutaminase autoantibodies (tTGA). Outcomes were the development of celiac disease autoimmunity (CDA) or celiac disease. CDA was defined as persistence of tTGA for at least 3 months or development of celiac disease. Celiac disease was defined based on detection of Marsh 2 or greater lesions in biopsy specimens or persistent high levels of tTGA. For each genotype, the cumulative incidence of CDA and celiac disease were determined. To estimate the cumulative incidence in the Denver general population, outcomes by each genotype were weighted according to the frequency of each of these genotypes in the general population. RESULTS: Of 1339 subjects followed up, 66 developed CDA and met criteria for celiac disease and 46 developed only CDA. Seropositivity for tTGA resolved spontaneously, without treatment, in 21 of the 46 subjects with only CDA (46%). The estimated cumulative incidence for CDA in the Denver general population at 5, 10, and 15 years of age was 2.4%, 4.3%, and 5.1%, respectively, and incidence values for celiac disease were 1.6%, 2.8%, and 3.1%, respectively. CONCLUSIONS: In a 20-year prospective study of 1339 children with genetic risk factors for celiac disease, we found the cumulative incidence of CDA and celiac disease to be high within the first 10 years. Although more than 5% of children may experience a period of CDA, not all children develop celiac disease or require gluten-free diets.

Manipulation of the Endocannabinoid System in Colitis: A Comprehensive Review.

BACKGROUND: Inflammatory bowel disease (IBD) is a lifelong disease of the gastrointestinal tract whose annual incidence and prevalence is on the rise. Current immunosuppressive therapies available for treatment of IBD offer limited benefits and lose effectiveness, exposing a significant need for the development of novel therapies. In the clinical setting, cannabis has been shown to provide patients with IBD symptomatic relief, although the underlying mechanisms of their anti-inflammatory effects remain unclear. METHODS: This review reflects our current understanding of how targeting the endocannabinoid system, including cannabinoid receptors 1 and 2, endogenous cannabinoids anandamide and 2-arachidonoylglycerol, atypical cannabinoids, and degrading enzymes including fatty acid amide hydrolase and monoacylglycerol lipase, impacts murine colitis. In addition, the impact of cannabinoids on the human immune system is summarized. RESULTS: Cannabinoid receptors 1 and 2, endogenous cannabinoids, and atypical cannabinoids are upregulated in inflammation, and their presence and stimulation attenuate murine colitis, whereas cannabinoid receptor antagonism and cannabinoid receptor deficient models reverse these anti-inflammatory effects. In addition, inhibition of endocannabinoid degradation through monoacylglycerol lipase and fatty acid amide hydrolase blockade can also attenuate colitis development, and is closely linked to cannabinoid receptor expression. CONCLUSIONS: Although manipulation of the endocannabinoid system in murine colitis has proven to be largely beneficial in attenuating inflammation, there is a paucity of human study data. Further research is essential to clearly elucidate the specific mechanisms driving this anti-inflammatory effect for the development of therapeutics to target inflammatory disease such as IBD.

Cannabis and Pediatric Inflammatory Bowel Disease: Change Blossoms a Mile High.

The trend toward decriminalization of cannabis (marijuana) continues sweeping across the United States. Colorado has been a leader of legalization of medical and recreational cannabis use. The growing public interest in the medicinal properties of cannabis and its use by patients with a variety of illnesses including inflammatory bowel disease (IBD) makes it important for pediatric gastroenterologists to understand this movement and its potential effect on patients. This article describes the path to legalization and "medicalization" of cannabis in Colorado and the public perception of safety despite the known adverse health effects of use. We delineate the mammalian endocannabinoid system and our experience of caring for children and adolescents with IBD in an environment of increasing awareness and acceptance of its use. We then summarize the rationale for considering that cannabis may have beneficial and harmful effects for patients with IBD. Finally, we highlight the challenges federal laws impose on conducting research on cannabis in IBD. The intent of this article is to inform health care providers about the issues around cannabis use and research in adolescents and young adults with IBD.

Intestinal lesions are associated with altered intestinal microbiome and are more frequent in children and young adults with cystic fibrosis and cirrhosis.

BACKGROUND AND AIMS: Cirrhosis (CIR) occurs in 5-7% of cystic fibrosis (CF) patients. We hypothesized that alterations in intestinal function in CF contribute to the development of CIR. AIMS: Determine the frequency of macroscopic intestinal lesions, intestinal inflammation, intestinal permeability and characterize fecal microbiome in CF CIR subjects and CF subjects with no liver disease (CFnoLIV). METHODS: 11 subjects with CFCIR (6 M, 12.8 yrs ± 3.8) and 19 matched with CFnoLIV (10 M, 12.6 yrs ± 3.4) underwent small bowel capsule endoscopy, intestinal permeability testing by urinary lactulose: mannitol excretion ratio, fecal calprotectin determination and fecal microbiome characterization. RESULTS: CFCIR and CFnoLIV did not differ in key demographics or CF complications. CFCIR had higher GGT (59±51 U/L vs 17±4 p = 0.02) and lower platelet count (187±126 vs 283±60 p = 0.04) and weight (-0.86 ± 1.0 vs 0.30 ± 0.9 p = 0.002) z scores. CFCIR had more severe intestinal mucosal lesions on capsule endoscopy (score ≥4, 4/11 vs 0/19 p = 0.01). Fecal calprotectin was similar between CFCIR and CFnoLIV (166 µg/g ±175 vs 136 ± 193 p = 0.58, nl <120). Lactulose:mannitol ratio was elevated in 27/28 subjects and was slightly lower in CFCIR vs CFnoLIV (0.08±0.02 vs 0.11±0.05, p = 0.04, nl ≤0.03). Small bowel transit time was longer in CFCIR vs CFnoLIV (195±42 min vs 167±68 p<0.001, nl 274 ± 41). Bacteroides were decreased in relative abundance in CFCIR and were associated with lower capsule endoscopy score whereas Clostridium were more abundant in CFCIR and associated with higher capsule endoscopy score. CONCLUSIONS: CFCIR is associated with increased intestinal mucosal lesions, slower small bowel transit time and alterations in fecal microbiome. Abnormal intestinal permeability and elevated fecal calprotectin are common in all CF subjects. Disturbances in intestinal function in CF combined with changes in the microbiome may contribute to the development of hepatic fibrosis and intestinal lesions.

Initial operative treatment of isolated ileal Crohn's disease in adolescents.

BACKGROUND: We hypothesize that in children with Crohn's disease (CD) isolated to a single site, resection leads to clinical improvement, decreased medication requirements, and improved growth. METHODS: A retrospective review was conducted of children with CD isolated to the terminal ileum undergoing operative intervention at Children's Hospital Colorado between 2002 and 2013. RESULTS: Twenty-six patients underwent ileocecetomy (mean age at diagnosis 14.1 ± 2.6 years; mean age at resection 15.7 ± 2.5 years; median follow-up 2 ± 1.5 years). Twenty-two (84.6%) patients reported clinical improvement and 17 (65.4%) were able to decrease the number or dosage of medications. Average weight increased from the 29th to the 45th percentile (P = .09) at 1 year and to the 56th percentile (P = .02) at 3 years post resection. Average body mass index increased from the 30th to the 48th and 49th percentile at 1 and 3 years (P < .05 for both), respectively. Height increased from the 39th percentile at the time of resection to the 51st percentile at 3 years (P = nonsignificant). CONCLUSION: Surgical resection of an isolated ileal segment in adolescents with CD allows for catch-up growth and reduction in medication requirements.

Appropriateness of emergency department use in pediatric inflammatory bowel disease: a quality improvement opportunity.

OBJECTIVES: We sought to characterize emergency department (ED) encounters for pediatric inflammatory bowel disease (IBD) to identify areas for prevention. METHODS: Retrospective chart review of 5 consecutive ED encounters at 7 centers was performed. RESULTS: Of 35 unique encounters by 32 patients, 3 main factors contributed to ED utilization: disease severity or course, day or time of care, and physician instruction. Of the ED encounters, approximately one-fifth were judged medically unnecessary, and one-half avoidable in a more optimal health care system. CONCLUSIONS: ED visits by pediatric patients with IBD may be reduced in a more optimal health care system.

Effectiveness of anti-TNFα for Crohn disease: research in a pediatric learning health system.

OBJECTIVES: ImproveCareNow (ICN) is the largest pediatric learning health system in the nation and started as a quality improvement collaborative. To test the feasibility and validity of using ICN data for clinical research, we evaluated the effectiveness of anti-tumor necrosis factor-α (anti-TNFα) agents in the management of pediatric Crohn disease (CD). METHODS: Data were collected in 35 pediatric gastroenterology practices (April 2007 to March 2012) and analyzed as a sequence of nonrandomized trials. Patients who had moderate to severe CD were classified as initiators or non-initiators of anti-TNFα therapy. Among 4130 patients who had pediatric CD, 603 were new users and 1211 were receiving anti-TNFα therapy on entry into ICN. RESULTS: During a 26-week follow-up period, rate ratios obtained from Cox proportional hazards models, adjusting for patient and disease characteristics and concurrent medications, were 1.53 (95% confidence interval [CI], 1.20-1.96) for clinical remission and 1.74 (95% CI, 1.33-2.29) for corticosteroid-free remission. The rate ratio for corticosteroid-free remission was comparable to the estimate produced by the adult SONIC study, which was a randomized controlled trial on the efficacy of anti-TNFα therapy. The number needed to treat was 5.2 (95% CI, 3.4-11.1) for clinical remission and 5.0 (95% CI, 3.4-10.0) for corticosteroid-free remission. CONCLUSIONS: In routine pediatric gastroenterology practice settings, anti-TNFα therapy was effective at achieving clinical and corticosteroid-free remission for patients who had Crohn disease. Using data from the ICN learning health system for the purpose of observational research is feasible and produces valuable new knowledge.

Implementable strategies and exploratory considerations to reduce costs associated with anti-TNF therapy in inflammatory bowel disease.

A health care system is needed where care is based on the best available evidence and is delivered reliably, efficiently, and less expensively (best care at lower cost). In gastroenterology, anti-tumor necrosis factor agents represent the most effective medical therapeutic option for patients with moderate-to-severe inflammatory bowel disease (IBD), but are very expensive and account for nearly a quarter of the cost of IBD care, representing a major area of present and future impact in direct health care costs. The ImproveCareNow Network, consisting of over 55 pediatric IBD centers, seeks ways to improve the value of care in IBD, curtailing unnecessary costs and promoting better health outcomes through systematic and incremental quality improvement initiatives. This report summarizes the key evidence to facilitate the cost-effective use of anti-tumor necrosis factor agents for patients with IBD. Our review outlines the scientific rationale for initiating cost-reducing measures in anti-tumor necrosis factor use and focuses on 3 implementable strategies and 4 exploratory considerations through practical clinical guidelines, as supported by existing evidence. Implementable strategies can be readily integrated into today's daily practice, whereas exploratory considerations can guide research to support future implementation.

Peutz-Jegher syndrome in childhood: need for updated recommendations?

BACKGROUND AND AIMS: We reviewed our institution's experience with Peutz-Jegher syndrome (PJS) in children to determine whether current recommendations on timing of screening and follow-up should be modified. METHODS: We reviewed the charts of all of the children with a diagnosis of PJS at our institution from 2000 to 2011 abstracting data on intussusceptions events, polyp characteristics, Sertoli cell (SC) tumors, family history, imaging, and interventions. RESULTS: Of 14 children identified, 10 were boys. Median age at first clinical evaluation was 4.5 years, and family history and/or mucocutaneous pigmentation were the 2 most common factors stimulating screening. Median age at first screening test was 5 years (range 1-16), and at first polyp identification, 5 years (range 1 to 18). There were 7 intussusception events in 5 children, with median age of 10 and range 5 to 16 for first event. Two boys had SC tumors at 8 and 11 years. Polyps were identified during initial screening in 9 of 14 patients. Polyps were found in the stomach or duodenum in 5 (36%), small bowel in 7, (50%) and colon in 3 (21%) children. Large polyps were identified in 9 children at median age of 7 years. CONCLUSIONS: Polyps causing significant clinical consequences can occur frequently in children with PJS younger than 8 years. Revised guidelines should consider initial screening at age 4 to 5 with capsule endoscopy and upper and lower endoscopy as well as evaluation for SC tumors and re-evaluation whenever symptoms suggest polyp-associated complications.

CLMP is required for intestinal development, and loss-of-function mutations cause congenital short-bowel syndrome.

BACKGROUND & AIMS: Short-bowel syndrome usually results from surgical resection of the small intestine for diseases such as intestinal atresias, volvulus, and necrotizing enterocolitis. Patients with congenital short-bowel syndrome (CSBS) are born with a substantial shortening of the small intestine, to a mean length of 50 cm, compared with a normal length at birth of 190-280 cm. They also are born with intestinal malrotation. Because CSBS occurs in many consanguineous families, it is considered to be an autosomal-recessive disorder. We aimed to identify and characterize the genetic factor causing CSBS. METHODS: We performed homozygosity mapping using 610,000 K single-nucleotide polymorphism arrays to analyze the genomes of 5 patients with CSBS. After identifying a gene causing the disease, we determined its expression pattern in human embryos. We also overexpressed forms of the gene product that were and were not associated with CSBS in Chinese Hamster Ovary and T84 cells and generated a zebrafish model of the disease. RESULTS: We identified loss-of-function mutations in Coxsackie- and adenovirus receptor-like membrane protein (CLMP) in CSBS patients. CLMP is a tight-junction-associated protein that is expressed in the intestine of human embryos throughout development. Mutations in CLMP prevented its normal localization to the cell membrane. Knock-down experiments in zebrafish resulted in general developmental defects, including shortening of the intestine and the absence of goblet cells. Because goblet cells are characteristic for the midintestine in zebrafish, which resembles the small intestine in human beings, the zebrafish model mimics CSBS. CONCLUSIONS: Loss-of-function mutations in CLMP cause CSBS in human beings, likely by interfering with tight-junction formation, which disrupts intestinal development. Furthermore, we developed a zebrafish model of CSBS.