Short-Term Overfeeding with Dairy Cream Does Not Modify Gut Permeability, the Fecal Microbiota, or Glucose Metabolism in Young Healthy Men.

Background: High-fat diets (HFDs) have been linked to low-grade inflammation and insulin resistance. Objective: The main purpose of the present study was to assess whether acute overfeeding with an HFD affects insulin sensitivity, gut barrier function, and fecal microbiota in humans. Methods: In a prospective intervention study, 24 healthy men [mean ± SD: age 23.0 ± 2.8 y, body mass index (in kg/m2) 23.0 ± 2.1] received an HFD (48% of energy from fat) with an additional 1000 kcal/d (as whipping cream) above their calculated energy expenditure for 7 d. Insulin sensitivity (hyperinsulinemic euglycemic clamp), gut permeability (sugar and polyethylene glycol absorption tests, plasma zonulin), and gut microbiota profiles (high-throughput 16S rRNA gene sequencing) were assessed before and after overfeeding, and 14 d after intervention. Additionally, inflammation markers such as high-sensitivity C-reactive protein, lipopolysaccharide-binding protein, leptin, high-molecular-weight adiponectin, calprotectin, regulated on activation normal, T cell expressed and secreted (RANTES), and monocyte chemoattractant protein-1 were measured in plasma by ELISA. Finally, lipid parameters were analyzed in serum by a laboratory service. Results: Although participants gained 0.9 ± 0.6 kg (P < 0.001) body weight, overnutrition was not associated with a significant change in insulin sensitivity (M value and glucose disposal). Overfeeding for 7 d resulted in elevated serum total (10.2%), LDL (14.6%) and HDL (14.8%) cholesterol concentrations (P < 0.01). In contrast, fasting plasma triglyceride significantly declined (29.3%) during overfeeding (P < 0.001). In addition, there were no significant changes in inflammatory markers. Urine excretion of 4 sugars and polyethylene glycol, used as a proxy for gut permeability, and plasma concentration of zonulin, a marker of paracellular gut permeability, were unchanged. Moreover, overfeeding was not associated with consistent changes in gut microbiota profiles, but marked alterations were observed in a subgroup of 6 individuals. Conclusions: Our findings suggest that short-term overfeeding with an HFD does not significantly impair insulin sensitivity and gut permeability in normal-weight healthy men, and that changes in dominant communities of fecal bacteria occur only in certain individuals. The study was registered in the German Clinical Trial Register as DRKS00006211.

Myosin IXb variants and their pivotal role in maintaining the intestinal barrier: a study in Crohn's disease.

BACKGROUND: Myosin IXb (MYO9B) is involved in the regulation of epithelial barrier function. We hypothesized that MYO9B variants are associated with increased intestinal permeability measured in patients with Crohn's disease (CD), where barrier dysfunction is crucially involved in disease development. METHODS: We sequenced MYO9B and genotyped five MYO9B variants (rs1545620, rs1457092, rs2279003, rs2305764 and rs2279002) and correlated these data to measurement of intestinal permeability in German CD patients (n = 122) obtained by standard oral sugar test using the lactulose/mannitol ratio after measurement of urinary excretion. We furthermore studied MYO9B variants in three European cohorts with inflammatory bowel disease (IBD) and healthy controls : Germany (CD = 264; ulcerative colitis = 143 [UC]; HC = 372); Hungary (CD = 147; UC = 117; HC = 195), the Netherlands (CD = 157; HC = 219). RESULTS: We found an association for four studied MYO9B variants to an increased intestinal permeability in CD patients (rs1545620, p = 0.010; rs1457092, p = 0.024; rs2279003, p = 0.003; rs2305764, p = 0.015). Furthermore, we observed significantly higher absolute values of intestinal permeability for individuals carrying risk alleles within MYO9B. Looking for an overall disease association, only the rs2305764 variant was associated with CD in the Dutch cohort (p = 0.004), but not in the German or Hungarian cohort. No association to UC or a distinct phenotype in both CD and UC patients was observed for all studied MYO9B variants. CONCLUSION: Our data suggest a link between MYO9B variants to an increased intestinal permeability in CD patients. This supports the influence of Myosin IXb on the integrity of the epithelial barrier. The role of MYO9B variants in the overall susceptibility to IBD, however, remains to be elucidated.

PTGER4 modulating variants in Crohn's disease.

PURPOSE: Variants modulating expression of the prostaglandin receptor 4 (PTGER4) have been reported to be associated with Cohn's disease (CD), but the clinical impact remains to be elucidated. We analyzed these variants in a large German inflammatory bowel disease (IBD) cohort and searched for a potential phenotype association. METHODS: The variants rs4495224 and rs7720838 were studied in adult German IBD patients (CD, n = 475; ulcerative colitis (UC), n = 293) and healthy controls (HC, n = 467). Data were correlated to results from NOD2 genotyping and to clinical characteristics. RESULTS: We found a significant association for the rs7720838 variant with overrepresentation of the T allele to CD (p = 0.0058; OR 0.7703, 95 % CI 0.641-0.926) but not to UC. Furthermore, logistic regression analysis revealed that the presence of the T allele was associated with stricturing disease behavior in CD patients (p = 0.03; OR 1.84, 95 % CI 1.07-3.16). Interestingly, the chance for developing stricturing disease behavior was enhanced if mutant alleles in both rs7720838 and NOD2 were present (OR 2.87, 95 % CI 1.42-5.81; p = 0.003). No overall association to CD or UC was found for the rs4495224 variant. CONCLUSIONS: The PTGER4 modulating variant rs7720838 increases susceptibility for CD and might resemble a risk factor for stricturing disease behavior.

Predictive Potential of Biomarkers of Intestinal Barrier Function for Therapeutic Management with Teduglutide in Patients with Short Bowel Syndrome.

INTRODUCTION: The human intestinal tract reacts to extensive resection with spontaneous intestinal adaptation. We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide. METHODS: Relevant regions of the GLP-2 receptor gene were sequenced. Gene expression analyses and immunohistochemistry were performed from mucosal biopsies. IP was assessed using a carbohydrate oral ingestion test. RESULTS: The study includes 59 SBS patients and 19 controls. Increases in gene expression with teduglutide were received for sucrase-isomaltase, sodium/glucose cotransporter 1, and calcium/calmodulin serine protein kinase. Mannitol recovery was decreased in SBS but elevated with teduglutide (Δ 40%), showed a positive correlation with remnant small bowel and an inverse correlation with parenteral support. CONCLUSIONS: Biomarkers predicting clinical and functional features in human SBS are very limited. Altered specific gene expression was shown for genes involved in nutrient transport but not for genes controlling tight junctions. However, mannitol recovery proved useful in describing the absorptive capacity of the gut during adaptation and treatment with teduglutide.

The JAK2 variant rs10758669 in Crohn's disease: altering the intestinal barrier as one mechanism of action.

PURPOSE: The aetiology of intestinal barrier dysfunction in Crohn's disease (CD) is poorly understood. Associations in relatives of CD families suggest a genetic basis, but the relevant variants are still unknown. We hypothesized that variants in genes occurring in pathways such as autophagy and IL23 signalling might contribute to CD by altering intestinal permeability. METHODS: We analysed five variants (rs10758669 within JAK2, rs744166 within STAT3, rs4958847, rs11747270 and rs13361189 within IRGM) in adult German inflammatory bowel disease patients (CD, n = 464; ulcerative colitis (UC), n = 292) and matched healthy controls (n = 508). These data were correlated with gastrointestinal permeability as assessed by lactulose/mannitol ratio in CD patients (n = 141) in remission. RESULTS: Our data confirm the association between JAK2 rs10758669 (p = 0.026, OR = 1.25, 95% CI = 1.04-1.50) and STAT3 rs744166 (p = 0.04, OR = 0.83, 95% CI = 0.688-0.998) with CD, but not UC. With respect to all the analysed IRGM variants, no association was found to either CD or UC. Among CD patients, an increased intestinal permeability was detected in 65 out of 141 patients (46.1%). Most importantly, patients carrying the C risk allele within JAK2 rs10758669 displayed an increased permeability more often compared with patients without the C allele (p = 0.004). No association with intestinal permeability was found for STAT3 rs744166 and all IRGM variants. CONCLUSIONS: JAK2 rs10758669 and STAT3 rs744166 increase susceptibility for CD. We show that the A>C substitution in rs10758669 of the JAK2 gene is associated with increased intestinal permeability. Altering intestinal barrier function might thus be one mechanism how JAK2 contributes to CD pathogenesis.

Long-term results of teduglutide treatment for chronic intestinal failure - Insights from a national, multi-centric patient home-care service program.

BACKGROUND & AIMS: Teduglutide is a Glucagon-like peptide-2 (GLP-2) agonist indicated for the treatment of patients with parenteral support (PS) dependent short bowel syndrome (SBS) with chronic intestinal failure (cIF). Its application is accompanied by a structured nation-wide home-care service program in Germany. We investigated care characteristics and outcome parameters in a clinical real-world observational setting. METHODS: Data generated within a therapy-accompanying home-care service program for adult SBS-cIF patients were analyzed retrospectively for patients treated up to 1 year (data cut: April 2020). RESULTS: In total, 52 teduglutide-treated patients were included by 6 German cIF centers. At teduglutide administration start, 49/52 patients were on PS, 3 of them without macronutrients. The majority of patients received individualized parenteral nutrition (PN) (n = 32/46), while 13/46 were on commercial premixed bags. PS application was done by patients themselves (37%), home-care nurses (19%), relatives (8%) or by a combination of those (16%). In patients with PS dependency at baseline and available follow-up data (n = 40-44), teduglutide treatment resulted in significantly reduced PN days, caloric needs, infusion time, and infusion volume after 6 and 12 months. After 1 year, reduction of infusion time was positively correlated with a reduction of PN calories and volume; 30 patients (68%) were responders (PS-volume reduction ≥20%), and 6 patients (14%) were completely weaned off PS. Sleep disturbances per night were significantly reduced after 3 months of treatment and stool characteristics improved in consistency and significantly in frequency, while meal frequency remained stable. CONCLUSIONS: Teduglutide treatment associated reduction in PS volume and calories was accompanied by reduced infusion days, infusion times, sleep disturbances, stable oral intake surrogates, and improved stool characteristics, all of these potential parameters for improving quality of life. Furthermore, analyzed care characteristics reflect SBS-cIF treatment as a complex, resource-intensive and demanding task for both, healthcare system and patients.

Clinical features of hemolysis, elevated liver enzymes, and low platelet count syndrome in undiagnosed Wilson disease: report of two cases.

INTRODUCTION: Wilson's disease (WD) is an autosomal recessive disorder characterized by toxic accumulation of copper mainly in the liver and brain. The hepatic manifestation of WD is diverse and may include asymptomatic elevation of aminotransferase, chronic hepatitis, cirrhosis, or acute/fulminant hepatic failure. Characteristic of acute hepatic failure in WD is concomitance of acute intravascular hemolytic anemia that in some patients may represent a first clinical symptom of WD. The diagnosis of acute Wilsonian liver failure is difficult, as similar signs may be observed in other clinical conditions. In pregnant patients with unrecognized WD, liver failure with hemolysis may be interpreted as the low platelet count (HELLP) syndrome. PATIENTS: We describe two women, who developed the clinical features of hemolysis, elevated liver enzymes, and HELLP syndrome. In both, further diagnostics confirmed WD. CONCLUSION: WD should be remembered in the differential diagnostics of HELLP syndrome.

Impact of Laparoscopic Sleeve Gastrectomy on Gut Permeability in Morbidly Obese Subjects.

BACKGROUND: Recent studies have suggested that obesity is associated with an increased intestinal permeability as well as an altered microbiota profile. These conditions can promote the translocation of lipopolysaccharide into the circulation and, subsequently, contribute to the observed systemic inflammation. Our aim was to assess gut permeability in patients with obesity compared to non-obese subjects as well as after excessive weight loss following laparoscopic sleeve gastrectomy (LSG). METHODS: We analyzed the dietary intake, metabolic and inflammatory markers, gut permeability (four-probe sugar test), and microbiota composition in 17 morbidly obese patients before and after LSG as well as in 17 age- and gender-matched non-obese subjects. Additionally, we compared gut permeability and inflammatory markers in patients of different stages of obesity. RESULTS: Patients with obesity showed elevated levels of C-reactive protein and lipopolysaccharide-binding protein as compared to non-obese subjects, but no differences were noted for gut permeability between these two groups. LSG led to improvements in metabolic and inflammatory parameters in the obese patients. Moreover, gastroduodenal as well as small intestinal permeability decreased, whereas colonic permeability increased after surgery. Regarding gut microbiota, differences were noted for main phyla and alpha-diversity between non-obese and obese subjects. After surgery, the composition of the microbiota showed a tendency toward the pattern of the non-obese group. CONCLUSIONS: Gut permeability is not dependent on body mass index, whereas weight loss after LSG initiates distinct changes in gastroduodenal, intestinal, and colonic permeability. These changes do not seem to be associated with changes in the microbiota composition. CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE: The trials were registered at https://www.drks.de/drks_web/ with the number DRKS00009008 and DRKS00006210.

Experience with teduglutide treatment for short bowel syndrome in clinical practice.

BACKGROUND & AIMS: Teduglutide, a glucagon-like peptide 2 (GLP-2) analog, is an approved medication specific for short bowel syndrome patients with chronic intestinal failure (SBS-IF). Due to its intestinotrophic properties, it improves intestinal absorption of fluids and nutrients, which was shown to reduce the need for parenteral support in clinical trials. The present report aims to describe the experience of teduglutide's effects in routine medical care with focus on clinical and nutritional effects. METHODS: Data of adult SBS-IF patients, treated with teduglutide between Sept. 2014 and May 2017 within a structured multidisciplinary program to enhance intestinal rehabilitation, were analyzed retrospectively from a single university medical center. RESULTS: In total, 27 patients were treated with teduglutide. Parenteral nutrition independency was achieved in 4/19 (21%) patients analyzed, with two remaining on intravenous fluids. A clinically significant reduction of parenteral volume was observed in 15/19 patients (79%) with onset between 1 and 45 weeks. Significant parenteral support reductions were observed, ranging from about -20% in patients treated for 3 months to about -45% in patients treated for 2 years. This was accompanied by an increase in parenteral nutrition-free days. We also report on a clinically relevant and significant effect of teduglutide-mediated improvement of stool frequency and consistency. Furthermore, nutritional status subgroup analysis revealed long-term stability in body weight, albumin levels and body composition albeit parenteral support reduction. Structural effects of teduglutide treatment were observed on small intestinal mucosa with significantly increased villus height, crypt depth and plasma citrulline levels. CONCLUSIONS: Teduglutide can be applied to anatomically and clinically heterogeneous SBS-IF patients and results in an adaptive response with variable time and effect range in routine medical care. Teduglutide-induced functional and structural changes bring on a gradual reduction of parenteral support at no cost to body composition and suggest an improved intestinal function with compensatory effect on nutritional status.

No association of the CARD8 (TUCAN) c.30T>A (p.C10X) variant with Crohn's disease: a study in 3 independent European cohorts.

BACKGROUND: A recent study reported that the c.30T>A (p.Cys10Ter; rs2043211) variant, in the CARD8 (TUCAN) gene, is associated with Crohn's disease (CD). The aim of this study was to analyze the frequency of p.C10X in 3 independent European (IBD) cohorts from Germany, Hungary, and the Netherlands. METHODS: We included a European IBD cohort of 921 patients and compared the p.C10X genotype frequency to 832 healthy controls. The 3 study populations analyzed were: (1) Germany [CD, n = 317; ulcerative colitis (UC), n = 180], (2) Hungary (CD, n = 149; UC, n = 119), and (3) the Netherlands (CD, n = 156). Subtyping analysis was performed in respect to NOD2 variants (p.Arg702Trp, p.Gly908Arg, c.3020insC) and to clinical characteristics. Ethnically matched controls were included (German, n = 413; Hungarian, n = 202; Dutch, n = 217). RESULTS: We observed no significant difference in p.C10X genotype frequency in either patients with CD or patients with UC compared with controls in all 3 cohorts. Conversely to the initial association study, we found a trend toward lower frequencies of the suggestive risk wild type in CD from the Netherlands compared with controls (P = 0.14). We found neither evidence for genetic interactions between p.C10X and NOD2 nor the C10X variant to be associated with a CD or UC phenotype. CONCLUSIONS: Analyzing 3 independent European IBD cohorts, we found no evidence that the C10X variant in CARD8 confers susceptibility for CD.

Effect of caloric restriction on gut permeability, inflammation markers, and fecal microbiota in obese women.

Recent findings suggest an association between obesity, loss of gut barrier function and changes in microbiota profiles. Our primary objective was to examine the effect of caloric restriction and subsequent weight reduction on gut permeability in obese women. The impact on inflammatory markers and fecal microbiota was also investigated. The 4-week very-low calorie diet (VLCD, 800 kcal/day) induced a mean weight loss of 6.9 ± 1.9 kg accompanied by a reduction in HOMA-IR (Homeostasis model assessment-insulin resistance), fasting plasma glucose and insulin, plasma leptin, and leptin gene expression in subcutaneous adipose tissue. Plasma high-molecular weight adiponectin (HMW adiponectin) was significantly increased after VLCD. Plasma levels of high-sensitivity C-reactive protein (hsCRP) and lipopolysaccharide-binding protein (LBP) were significantly decreased after 28 days of VLCD. Using three different methods, gut paracellular permeability was decreased after VLCD. These changes in clinical parameters were not associated with major consistent changes in dominant bacterial communities in feces. In summary, a 4-week caloric restriction resulted in significant weight loss, improved gut barrier integrity and reduced systemic inflammation in obese women.

A Promoter Variant Within the Aryl Hydrocarbon Receptor Gene Is Associated with an Epithelial Barrier Defect in Smokers with Crohn's Disease.

BACKGROUND: Smoking worsens Crohn's disease (CD). The aryl hydrocarbon receptor (AhR) is a transcription factor that mediates the toxicity of dioxinlike chemicals. We hypothesized that AHR variants and smoking influence CD. METHODS: Exon-intron boundaries and coding and promoter regions of AHR gene were sequenced (28 patients with inflammatory bowel disease; 4 healthy controls). Two identified variants (rs7796976 and rs2066853) were studied for an association with intestinal permeability (IP, oral sugar test) in patients with inflammatory bowel disease (stratified according to the smoking status). AHR expression was analyzed by quantitative real-time polymerase chain reaction in colonic biopsies from patients with CD (n = 53). Case-control analysis including a genotype-phenotype correlation was performed for both variants (n = 767 patients with inflammatory bowel disease; n = 466 healthy controls). RESULTS: Sequencing identified a putative promoter variant (rs7796976) and a nonsynonymous variant (rs2066853; Arg554Lys) in AHR, both predicted to be functionally relevant. The major G-allele of rs7796976 increased the risk for disturbed IP (odds ratio 1.9, 95% confidence interval [CI], 1.1-3.2) in CD but not ulcerative colitis. We observed an additive effect of the rs7796976 genotype and smoking on IP (P = 0.005), which was also shown for rs2066853 (P = 0.004; variants not linked). Both variants showed a genotype-dependent AHR expression in colonic biopsies of patients with CD. No overall association with either CD or ulcerative colitis was observed; however, the rs7796976 genotype and smoking increased the risk for the L4 phenotype in CD. CONCLUSION: Smoking and functionally relevant AHR variants increase IP in CD. Because AhR is known to mediate between smoking and inflammation, these variants might be involved in the deleterious effect of smoking on CD.

Increased small intestinal permeability in ulcerative colitis: rather genetic than environmental and a risk factor for extensive disease?

BACKGROUND: A disturbed epithelial barrier could play a pivotal role in ulcerative colitis (UC). We performed a family-based study analyzing in vivo gastrointestinal permeability in patients with UC, their healthy relatives, spouses, and controls. METHODS: In total, 89 patients with UC in remission, 35 first-degree relatives (UC-R), 24 nonrelated spouses (UC-NR), and 99 healthy controls (HC) were studied. Permeability was assessed by a sugar-drink test using sucrose (gastroduodenal permeability), lactulose/mannitol (intestinal permeability), and sucralose (colonic permeability). Data were correlated with clinical characteristics including medical treatment. RESULTS: Increased intestinal permeability was detected significantly more often in UC patients in remission (25/89, 28.1%) compared with HC (6/99, 6.1%; P < 0.001). Similar results were obtained in UC-R (7/35, 20.0%; P = 0.01 compared with HC) regardless of sharing the same household with the patients or not. No difference was found between UC-NR (3/24, 12.5%) and HC. Notably, in UC patients increased intestinal permeability was found in 12/28 patients (42.9%) with pancolitis, 7/30 (23.3%) patients with left-sided colitis, and in 2/19 (10.5%) patients with proctitis (P = 0.04). Gastroduodenal and colonic permeability were similar in all groups. Among patients on azathioprine, increased intestinal permeability was only seen in 1/18 (5.6%) patients. In contrast, in 24/70 (34.3%) patients without azathioprine, an increased intestinal permeability was found (P = 0.005). CONCLUSIONS: An increased intestinal but not colonic permeability was found in UC patients in clinical remission that could mark a new risk factor for extensive disease location. Similar findings in healthy relatives but not spouses suggest that this barrier defect is genetically determined.

Prevalence of germline mutations in the TTR gene in a consecutive series of surgical pathology specimens with ATTR amyloid.

Transthyretin-derived amyloidosis (ATTR) amyloidosis is the third most prevalent amyloid type in surgical pathology and may occur as a hereditary disease with germline mutations in the TTR gene or as senile systemic amyloidosis (SSA) without mutations. Distinction between hereditary ATTR amyloidosis and SSA is of central importance, as the former necessitates genetic counseling and can be treated by liver transplantation. However, little is known about the prevalence of hereditary ATTR amyloidosis in surgical pathology specimens. We have examined the distribution of hereditary ATTR amyloidosis and SSA in a consecutive series of surgical pathology specimens with histologically and immunohistochemically confirmed ATTR amyloid. Thirty-three consecutive patients were retrieved from the Amyloid Registry of the Charité University Hospital. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tissue or patient blood and examined by DNA sequencing. ATTR amyloid was found in the gastrointestinal tract, endomyocardium, peripheral nerve, carpal tunnel ligament, synovia, breast, and testicle. Amyloid fibrils were present as interstitial and vascular deposits, as evidenced by Congo red staining. TTR gene mutations were detected in 12 of 30 patients, with p.Val30Met being the most prevalent (5 patients). Furthermore, 2 novel mutations (p.Asp39Val and p.Glu54Asp) were found. In patients carrying a mutation, ATTR amyloid was found in the gastrointestinal tract, myocardium, nerve, and testicles. To conclude, the hereditary form of ATTR amyloid seems to be more common in elderly patients than previously thought. It is, therefore, important to genetically test every patient when diagnosing ATTR amyloidosis.

Hereditary apolipoprotein AI-associated amyloidosis in surgical pathology specimens: identification of three novel mutations in the APOA1 gene.

Apolipoprotein AI-derived (AApoAI) amyloidosis may present either as a non-hereditary form with wild-type protein deposits in atherosclerotic plaques or as a hereditary form due to germline mutations in the APOA1 gene. Currently, more than 50 apoAI variants are known, and 13 are associated with amyloidosis. We describe six patients with AApoAI amyloidosis due to APOA1 germline mutations that affect the larynx, small intestine, large intestine, heart, liver, kidney, uterus, ovary, or pelvic lymph nodes. In each patient, the amyloid showed a characteristic apple green birefringence when viewed under polarized light after Congo red staining and was immunoreactive with antibodies against apoAI. Sequence analyses revealed one known (p.Leu75Pro) and three novel APOA1 mutations that included gene variations leading to two different frameshifts (p.Asn74fs and p.Ala154fs) and one amino acid exchange (p.Leu170Pro). These three novel mutations extend our knowledge about both the location of the mutations and the organ distribution in hereditary AApoAI amyloidosis. Thirteen of the now sixteen amyloidogenic mutations are localized in two hot-spot regions that span residues 50 to 93 and 170 to 178. The organ distribution and clinical presentation of AApoAI amyloidosis seems to depend on the position of the mutation. Patients with alterations in codons 1 to 75 mostly develop hepatic and renal amyloidosis, while carriers of mutations in residues 173 to 178 mainly suffer from cardiac, laryngeal, and cutaneous amyloidosis.

Mutational analysis of ATP7B gene in Egyptian children with Wilson disease: 12 novel mutations.

The aim of this work was to study the mutations within ATP7B in Egyptian children with Wilson disease and to evaluate any potential correlation between genotype and phenotype in this cohort. The study consisted of 48 children with Wilson disease from 32 independent families. The 21 exons of the ATP7B gene were amplified in a thermal cycler. Direct sequencing of the amplified polymerase chain reaction (PCR) products was performed by cycle sequencing using fluorescent dye terminators in an automatic ABI sequencer. Thirty-one different mutations in 96 chromosomes were detected (19 missense, three nonsense, seven frameshift deletions, and two splice-site mutations). Of these, 12 mutations have not been previously reported. The p.N1270S, p.C703Y, IVS18-2A > G, p.R1319X, c.2304-2305insC, and p.H1069Q were present in 7.8%, 6.2%, 6.2%, 6.2%, 4.7%, and 4.7%, respectively, of studied chromosomes in independent families. One patient was homozygous for both p.N1270S and p.T1434M mutations. Frameshift and nonsense mutations were found in 50% of patients with disease onset < or =8 years compared with only 26% in patients with onset >8 years. Despite mutation heterogeneity in Egyptian children, genotype-phenotype correlation analysis seems to be promising in this population, as many patients carry homozygous mutations, a situation that mandates a larger-scale population screening to identify the carrier rate in this community.

A study in three European IBD cohorts confirms that the ATG16L1 c.898A>G (p.Thr300Ala) variant is a susceptibility factor for Crohn's disease.

BACKGROUND AND AIMS: A recent study reported that a nonsynonymous SNP rs2241880 (c.898A>G, p.Thr300Ala) within ATG16L1 confers susceptibility to Crohn's disease (CD). We analyzed ATG16L1 c.898A>G in three independent European inflammatory bowel disease (IBD) cohorts from Germany, Hungary and the Netherlands. METHODS: In total, we included 910 European IBD patients and compared the ATG16L1 c.898A>G genotype frequency with 707 ethnically matched healthy controls. We included patients from 3 populations originating from Germany (CD n=310; ulcerative colitis [UC] n=179), Hungary (CD n=147; UC n=117), and the Netherlands (CD n=157). Subtyping analysis was performed in respect to CARD15 alterations and clinical characteristics. RESULTS: We found a highly significant association of c.898A>G to CD. The association was significant (p=0.0005) for the total CD cohort but also for the individual populations from Germany (p=0.02) and Netherlands (p=0.02) whereas in the Hungarian CD patients a clear trend was observed (p=0.19; OR 1.227, 95% CI 0.910; 1.654). No association was found between c.898A>G and UC. No statistical interactions were observed between ATG16L1 c.898A>G and CARD15 variants. Furthermore no association to a CD subphenotype was detected. CONCLUSIONS: We confirm that ATG16L1 variant c898A>G confers a risk variant for CD but is not associated with a distinct CD phenotype.