Disaccharidase deficiencies and gastrointestinal symptoms in patients referred to gastroscopic examination: a single center study from Norway.

OBJECTIVE: Gastrointestinal illnesses have been reported in relation to low disaccharidase activity, yet both the prevalence of disaccharidase deficiency and its association with gastrointestinal symptoms and irritable bowel syndrome (IBS) are largely unknown. We aimed to determine the association between low activity of disaccharidase enzymes on gastrointestinal symptoms and presence of IBS. METHODS: Patients referred for gastroscopic examination due to gastrointestinal complaints were consecutively included. A pinch biopsy was taken from the distal part of duodenum, and disaccharidase activity was measured using the Dahlqvist method. Gastrointestinal symptom severity was measured using IBS-Symptom Severity Score (IBS-SSS). RESULTS: A total of 40 patients were included. Disaccharidase deficiency was detected in 24 patients (60%). Half of the patients (n = 21) had IBS according to Rome IV criteria. A majority (75%) of all patients reported moderate to severe gastrointestinal symptoms. Moderate to severe gastrointestinal symptoms were reported by 16 patients (67%) with disaccharidase deficiency and in 14 patients (88%) with normal disaccharidase activity. Lactase deficiency was detected in 22 patients (55%), maltase deficiency in 11 patients (28%), sucrase deficiency in 9 patients (23%), isomaltase deficiency in 13 patients (33%) and glucoamylase deficiency in 12 patients (30%). The activity of all enzymes was reduced in 8 patients (20%). Degree of disaccharidase deficiency was not associated with either the severity of gastrointestinal symptoms or the diagnosis of IBS. Enzymes levels were not associated with gastrointestinal symptom scores. CONCLUSION: Our findings did not reveal any association between biochemically measured disaccharidase deficiency and gastrointestinal symptoms or the presence of IBS.

Fructose malabsorption and fructan malabsorption are associated in patients with irritable bowel syndrome.

BACKGROUND: Food malabsorption and intolerance is implicated in gastrointestinal symptoms among patients with irritable bowel syndrome (IBS). Key triggers include fructose and fructan. Prior studies examined fructose and fructan malabsorption separately in IBS patients. None have concurrently assessed both within the same patient group. We aimed to investigate the association between fructose and fructan malabsorption in the same patients with IBS using hydrogen breath testing (HBT). METHODS: We retrospectively identified patients with IBS who underwent fructose and fructan HBTs and abstracted their results from the electronic medical record. Fructose and fructan HBTs were performed by administering a 25 g fructose solution or 10 g fructan solution, followed by breath hydrogen readings every 30 min for 3 h. Patients were positive for fructose or fructan malabsorption if breath hydrogen levels exceeded 20 ppm. RESULTS: Of 186 IBS patients, 71 (38.2%) were positive for fructose malabsorption and 91 (48.9%) were positive for fructan malabsorption. Of these patients, 42 (22.6%) were positive for fructose malabsorption and fructan malabsorption. Positive fructose HBT readings were significantly associated with positive fructan HBT readings (p = 0.0283). Patients positive for fructose malabsorption or fructan malabsorption had 1.951 times higher odds of testing positive for the other carbohydrate. CONCLUSIONS: Our results reveal a clinically significant association between fructose malabsorption and fructan malabsorption in patients with IBS. Fructan malabsorption should be assessed in patients with fructose malabsorption, and vice versa. Further studies are required to identify the mechanisms underlying our findings.

Coexisting Th1 and Th2 cytokines in patients with collagenous gastritis and implications for its pathogenesis.

OBJECTIVES: Collagenous gastritis (CG) is a rare cause of refractory dyspepsia and anemia that frequently affects children and young adults and whose histological hallmark is chronic mucosal inflammation with a subepithelial collagen band. The etiology remains obscure, and no established treatments exist. We investigated the pathogenesis of CG by determining the expression profiles of genes related to immunity and inflammation in index biopsies. METHODS: Gastric biopsies from 10 newly diagnosed patients with CG were evaluated using the NanoString nCounter assay. Gastric biopsies from 14 normal individuals served as controls. The gene expression ratios for CG versus controls were determined in pooled samples and confirmed in individual samples by quantitative reverse transcription polymerase chain reaction. The results were compared with previously reported expression data from a cohort of patients with collagenous colitis, a colonic disorder with similar morphology, including subepithelial collagen band. RESULTS: CG biopsies featured enhanced expression of key genes encoding both Th1 (IFNγ, TNF-α, IL-2, IL-10, IL-12A, IL-12B, and IL-18) and Th2 cytokines (IL-3, IL-4, IL-5, IL-6, and IL-13). In contrast, biopsies from patients with CC exhibited upregulated Th1 cytokines only. CONCLUSIONS: We show in this first published gene expression profiling study that CG involves simultaneous upregulation of Th1 and Th2 cytokines. This finding is unique, contrasting with other types of chronic gastritis as well as with collagenous colitis, which shares the presence of a collagen band. Involvement of Th2 immunity in CG would support further investigation of potential dietary, environmental, or allergic factors to guide future therapeutic trials.

Mucocutaneous manifestations of inflammatory bowel disease.

Mucocutaneous manifestations can be indicative of a variety of gastrointestinal diseases, and the dermatologist needs to know how to recognize them to refer the right patients to the gastroenterologist. Conversely, the gastroenterologist is often confronted with mucocutaneous lesions that raise the question of a possible association with a known digestive disease. Among the extra-intestinal manifestations of inflammatory bowel disease (IBD), mucocutaneous manifestations are the most common. This review will provide a breakdown by classifying them into 4 groups: 1) reactive manifestations, which include neutrophilic dermatoses, aphthous stomatitis, erythema nodosum, and vasculitis; 2) Crohn's disease-specific granulomatous skin lesions, which are histologically characterized by tuberculoid granulomas similar to those found in the gastrointestinal tract; 3) nutritional deficiency manifestations secondary to anorexia, malabsorption, loss, and drug interactions; and 3) a variety of autonomous autoimmune or inflammatory skin diseases. Dermatologists may also be involved in the management of the adverse effects of IBD treatments, especially the so-called "paradoxical" psoriatic eruptions.

Bile Acid Malabsorption in Patients with Neuroendocrine Tumors.

BACKGROUND: Chronic diarrhea in patients with neuroendocrine tumors (NET) may be caused by bioactive products of NET, bile acid malabsorption (BAM), ileal resection (IR) or steatorrhea. AIM: To quantitate BA and fat malabsorption in NET with diarrhea. METHODS: Part of evaluation in medical oncology clinical practice, 67 patients [42F, 25 M; median age 64.0 y (17.0 IQR)] with well-differentiated NET and diarrhea underwent clinically indicated measurements of 48-h fecal BA [(FBA), fecal weight (normal < 400 g/48 h), fecal fat (normal < 7 g/day) in n = 52] and fasting serum 7αC4 (marker of hepatic BA synthesis, n = 30) between 01/2018 and 11/2020. IR had been performed in 45 patients. BAM diagnosis was based on FBA criteria: elevated total FBA (> 2337 µmol/48 h) or > 10% primary FBA or combination > 4% primary FBA plus > 1000 µmol total FBA/48 h. We also measured fecal elastase (for pancreatic insufficiency) in 13 patients. RESULTS: BAM was present in 48/52 (92%) patients with NET. There were significant correlations between total FBA and 48-h fecal weight (Rs = 0.645, P < 0.001). Mean length of IR was 47 cm; in patients with IR < 25 cm, total FBA was elevated in 85% and primary FBA > 10% in 69%. In 22 patients with no IR, 13/15 tested (87%) had BAM. Among 6 patients with pancreatic NET and no IR, 80% had BAM. Fecal fat was ≥ 15 g/day in 18/42 (43%). In 4/17 (24%) with IR < 25 cm and 8/19 (42%) patients with IR > 25 cm fecal fat was 44.0 (40.5) and 38.0 (38.0)g/day, respectively. CONCLUSION: A majority of patients with NET and diarrhea had BAM, even with < 25 cm or no IR.

Chronic diarrhea - The poetic masquerade.

Chronic diarrhea, by definition, is the passage of loose/liquid stools, with increased frequency (more than three times/day), or an output of over 200 g/day, lasting for a duration of four or more weeks. The clinical approach to identify the cause of chronic diarrhea generally depends on the local socioeconomic status. In high-income countries, systemic causes such as irritable bowel syndrome (IBS), inflammatory bowel disease, malabsorption syndromes (lactose intolerance/coeliac disease) are primarily considered. In mid- to low-income countries, infective causes like chronic bacterial, mycobacterial, fungal infections, HIV, bowel cancer are considered before systemic causes/malabsorption syndromes. Amyloidosis, more accurately, reactive amyloidosis is one of the rarer causes of chronic/persistent diarrhea. Inflammatory colitis secondary to POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) as a cause for chronic diarrhea has been reported only in a handful of cases and is often missed. We present such a case of chronic diarrhea in a middle-aged man, who was eventually diagnosed to have POEMS syndrome.

Expanding the clinical spectrum in trichohepatoenteric syndrome.

Trichohepatoenteric syndrome (THES) is a very rare autosomal recessive genetic disorder, which is characterized by intractable diarrhea during infancy, dysmorphic features, immunodeficiency, and a failure to thrive. There are still significant difficulties for patients and clinicians in terms of the management of THES, even though its molecular basis has been uncovered in the last decade. In this article, we have presented two cases relating to siblings that have been diagnosed with the condition. Concerning one of the patients, we described a novel variation (c.2114 + 5G > A) in the TTC37 gene and a mild clinical course; meanwhile, the other one was clinically diagnosed with THES at 17 years of age, but they had seizures and died suddenly. These cases expand the spectrum of clinical findings in relation to THES.

Parenteral iron therapy and phosphorus homeostasis: A review.

Phosphorus has an essential role in cellular and extracellular metabolism; maintenance of normal phosphorus homeostasis is critical. Phosphorus homeostasis can be affected by diet and certain medications; some intravenous iron formulations can induce renal phosphate excretion and hypophosphatemia, likely through increasing serum concentrations of intact fibroblast growth factor 23. Case studies provide insights into two types of hypophosphatemia: acute symptomatic and chronic hypophosphatemia, while considering the role of pre-existing conditions and comorbidities, medications, and intravenous iron. This review examines phosphorus homeostasis and hypophosphatemia, with emphasis on effects of iron deficiency and iron replacement using intravenous iron formulations.

INFLUENCE OF CARBOHYDRATE MALABSORPTION SYNDROME ON THE CLINICAL COURSE OF ROTAVIRUS INFECTION IN CHILDREN AT AN EARLY AGE.

The aim of the work - to determine the pathogenetic role of carbohydrate malabsorption syndrome in severity and duration of rotavirus infection symptoms in early aged children. The study included 60 breastfed children aged 1-24 months with rotavirus infection. The severity and duration of the main symptoms of rotavirus gastroenteritis were analyzed depending on the dynamic changes in laboratory parameters of carbohydrate malabsorption syndrome: the total amount of reducing carbohydrates in feces, lactose and glucose in feces, which were determined on II-III, V, VII and X days of the disease. To determine the total amount of reducing sugars in the coprofiltrates, the Benedict's test was used, the lactose in the feces was determined using the Malfatti's test, and the glucose was determined by the Glucophane test systems (Erba Lachema). It was found that the syndrome of carbohydrate malabsorption had the maximum pathogenetic effect on the severity of rotavirus diarrhea after the fifth day of the disease mainly due to lactase deficiency. Starting from the seventh day of rotavirus infection, with an increase in the level of carbohydrates in the feces by 0,5%, the frequency of liquid stools increases by 1 time per day. The prognostic sign of long-term diarrheal syndrome (≥9 days) is the total level of reducing sugars in the feces ≥1% on the fifth day of illness. If the result of the Benedict's test increases by 0,4% in this term, the duration of diarrhea increases by 1 day. When the level of carbohydrates in the stool ≥ 0,75% on the tenth day of the disease the risk of residual effects on discharge from the hospital (such as unstable stools 2-3 times a day, meteorism and flatulence) increases.

Fructose and irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a chronic disorder characterised by recurrent abdominal pain or discomfort and transit disturbances with heterogeneous pathophysiological mechanisms. The link between food and gastrointestinal (GI) symptoms is often reported by patients with IBS and the role of fructose has recently been highlighted. Fructose malabsorption can easily be assessed by hydrogen and/or methane breath test in response to 25 g fructose; and its prevalence is about 22 % in patients with IBS. The mechanism of fructose-related symptoms is incompletely understood. Osmotic load, fermentation and visceral hypersensitivity are likely to participate in GI symptoms in the IBS population and may be triggered or worsened by fructose. A low-fructose diet could be integrated in the overall treatment strategy, but its role and implication in the improvement of IBS symptoms should be evaluated. In the present review, we discuss fructose malabsorption in adult patients with IBS and the interest of a low-fructose diet in order to underline the important role of fructose in IBS.

Metabolic bone diseases in intestinal failure.

Metabolic bone diseases are a group of conditions that are common complications in patients with intestinal failure. These may occur as a result of the underlying condition, leading to intestinal failure, particularly inflammatory conditions such as Crohn's disease and their associated treatments including corticosteroids. Malabsorption, as a result of a loss of enterocyte mass or gut function, of many nutrients, including vitamin D, may further compound metabolic bone problems, and there has been historical contamination of parenteral nutrition with aluminium that has prevented normal bone metabolism contributing to osteoporosis. This review looks at the diagnosis and current management of bone health in patients with intestinal failure.

Chronic Diarrhea in Adults: Evaluation and Differential Diagnosis.

Chronic diarrhea is defined as a predominantly loose stool lasting longer than four weeks. A patient history and physical examination with a complete blood count, C-reactive protein, anti-tissue transglutaminase immunoglobulin A (IgA), total IgA, and a basic metabolic panel are useful to evaluate for pathologies such as celiac disease or inflammatory bowel disease. More targeted testing should be based on the differential diagnosis. When the differential diagnosis is broad, stool studies should be used to categorize diarrhea as watery, fatty, or inflammatory. Some disorders can cause more than one type of diarrhea. Watery diarrhea includes secretory, osmotic, and functional types. Functional disorders such as irritable bowel syndrome and functional diarrhea are common causes of chronic diarrhea. Secretory diarrhea can be caused by bile acid malabsorption, microscopic colitis, endocrine disorders, and some postsurgical states. Osmotic diarrhea can present with carbohydrate malabsorption syndromes and laxative abuse. Fatty diarrhea can be caused by malabsorption or maldigestion and includes disorders such as celiac disease, giardiasis, and pancreatic exocrine insufficiency. Inflammatory diarrhea warrants further evaluation and can be caused by disorders such as inflammatory bowel disease, Clostridioides difficile, colitis, and colorectal cancer.

'Rapid transit' constipation in children: a possible genesis for irritable bowel syndrome.

Children with chronic idiopathic constipation (CIC) often end up at the surgeon when medical treatments have failed. This opinion piece discusses a recently described pattern of CIC called 'Rapid transit constipation (RTC)' first identified in 2011 as part of surgical workup. RTC was identified using a nuclear medicine gastrointestinal transit study (NMGIT or nuclear transit study) to determine the site of slowing within the bowel and to inform surgical treatment. Unexpectedly, we found that RTC occured in 29% of 1000 transit studies in a retrospective audit. Irritable bowel syndrome (IBS) occurs in 7-21% of the population, with a higher prevalence in young children and with constipation type dominating in the young. While 60% improve with time, 40% continue with symptoms. First-line therapy for IBS in adults is a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols which reduces symptoms in > 70% of patients. In children with functional gastrointestinal disorders, fructose intolerance occurs in 35-55%. Reducing fructose produced significant improvement in 77-82% of intolerant patients. In children with RTC and a positive breath test upon fructose challenge, we found that exclusion of fructose significantly improved constipation, abdominal pain, stool consistency and decreased laxative use. We hypothesise that positive breath tests and improvement of pain and bowel frequency with sugar exclusion diets in RTC suggest these children have IBS-C. These observations raise the possibility that many children with CIC could be treated by reducing fructose early in their diet and this might prevent the development of IBS in later life.

Dermatological Manifestations in Pediatric Inflammatory Bowel Disease.

Background and Objectives: Over the last years, inflammatory bowel disease (IBD) has been reported on a high incidence in pediatric populations and has been associated with numerous extraintestinal manifestations, making its management a real challenge for the pediatric gastroenterologist. Dermatological manifestations in IBD are either specific, related to the disease activity or treatment-associated, or non-specific. This literature review aims to identify and report the dermatological manifestations of IBD in children, the correlation between their appearance and the demographical characteristics, the relationship between these lesions and disease activity, and to highlight the impact of dermatological manifestations on an IBD treatment regime. MATERIALS AND METHODS: A systemic literature review was performed, investigating articles and case reports on dermatological manifestations in children with IBD starting from 2005. A total of 159 potentially suitable articles were identified and after the exclusion process, 75 articles were selected. RESULTS: The most common dermatological manifestations reported in pediatric IBD are erythema nodosum and pyoderma gangrenosum. More rare cases of metastatic Crohn's disease, epidermolysis bullosa acquisita, small-vessel vasculitis, necrotizing vasculitis, leukocytoclastic vasculitis, cutaneous polyarteritis nodosa, and Sweet's syndrome have been reported. Oral manifestations of IBD are divided into specific (tag-like lesions, mucogingivitis, lip swelling with vertical fissures, aphthous stomatitis, and pyostomatitis vegetans) and non-specific. IBD treatment may present with side effects involving the skin and mucosa. Anti-tumor necrosis factor agents have been linked to opportunistic skin infections, psoriasiform lesions, and a potentially increased risk for skin cancer. Cutaneous manifestations such as acrodermatitis enteropathica, purpuric lesions, and angular cheilitis may appear secondary to malnutrition and/or malabsorption. CONCLUSIONS: The correct diagnosis of dermatological manifestations in pediatric IBD is of paramount importance because of their impact on disease activity, treatment options, and a patient's psychological status.

Chronic diarrhoea in adults: what not to miss.

PURPOSE OF REVIEW: Chronic diarrhoea remains a diagnostic challenge, with numerous causes and few effective symptomatic treatments. This review focuses on new methods for diagnosis of common disorders and alerts readers to rarer causes through a systematic approach to the underlying mechanisms. RECENT FINDINGS: New strategies are emerging to stratify the need for endoscopic investigation. Faecal immunochemical testing, combined with standard blood tests, shows promise in excluding colorectal cancers, adenoma and inflammatory bowel disease, challenging the current use of faecal calprotectin. Serum analysis for markers of bile acid synthesis has been refined, potentially streamlining diagnostic pathways of bile acid malabsorption for those who are unable to access nuclear medicine scans, but the positive predictive value of faecal elastase in low prevalence populations has been questioned. Novel markers such as volatile organic compounds and stool DNA analyses continue to develop. SUMMARY: A systematic approach to investigation of chronic diarrhoea will ensure all relevant causes are considered and minimize the chance of a missed diagnosis. Combination of clinical features with noninvasive testing supports a judicious approach to endoscopic investigations but further innovation will be needed to resolve the diagnostic challenge that diarrhoea poses.

Zinc Absorption and Endogenous Fecal Zinc Losses in Bangladeshi Toddlers at Risk for Environmental Enteric Dysfunction.

OBJECTIVES: Environmental enteric dysfunction (EED) impairs zinc absorption from food, and zinc deficiency may contribute to the poor growth associated with EED. We examined zinc absorption from a standardized aqueous zinc dose, and habitual daily endogenous fecal zinc excretion (EFZ) and compared these outcomes between children grouped by the lactulose to mannitol ratio (L:M). METHODS: Bangladeshi toddlers (18-24 months) with low (<0.09) and high (≥0.09) L:M were administered isotope-labeled 3 mg aqueous zinc in the fasted state. Fractional absorption of zinc (FAZ) and EFZ were measured by dual stable isotope tracer method and an isotope dilution method, respectively. Secondary aims included examining relationships of biomarkers of systemic and intestinal inflammation and gut function with FAZ and EFZ. RESULTS: Forty children completed the study; nearly all had evidence of EED. No differences in zinc homeostasis measurements (mean ±â€ŠSD) were observed between high and low L:M groups: FAZ was 0.38 ±â€Š0.19 and 0.31 ±â€Š0.19, respectively; both figures were within estimated reference range. Means of EFZ were 0.73 ±â€Š0.27 and 0.76 ±â€Š0.20 mg/day for high and low L:M, respectively, and were 10% to 15% above estimated reference range. Regression analyses indicated that biomarkers of systemic inflammation were directly associated with increasing FAZ, consistent with increased gut permeability. Biomarkers of intestinal inflammation were negatively associated with EFZ, consistent with low-zinc intake and chronic deficiency. CONCLUSIONS: In these children at risk of EED, endogenous zinc losses were not markedly increased. Results suggest that efforts to improve zinc status in EED should focus on substantially improving zinc intakes.

Fructose malabsorption in asymptomatic children and in patients with functional chronic abdominal pain: a prospective comparative study.

The objective of this prospective cohort study was to compare fructose malabsorption in patients with functional chronic abdominal pain and in healthy children. The sample was divided into two groups: asymptomatic children and pain-predominant functional gastrointestinal disorders according to the Rome IV criteria. All children were tested for fructose malabsorption by a standardized breath hydrogen test. Hydrogen and methane were measured and the test was presumed positive when it exceeded 20 ppm above baseline. If positive, patients were given a low-fructose diet and the response was evaluated. One hundred five children were included (34 healthy children, 71 with functional chronic abdominal pain), with similar demographic characteristics in both groups (35.2% male, age 9.5 ± 2.8 years). Hydrogen levels in breath were tested through a hydrogen test for fructose demonstrating malabsorption in 58.8% of healthy children (95%CI 40.8%-76.8%) and in 40.8% of children with chronic abdominal pain (95%CI 28.7%-53.0%), removing those who had bacterial overgrowth. Twenty-one of 31 patients with symptoms and a positive test (72.4%) reported an improvement on a low-fructose diet.Conclusion: Fructose malabsorption is more common in asymptomatic children than in patients with chronic abdominal pain. Better standardized test conditions are necessary to improve accuracy of diagnosis before using this test in clinical practice. What is Known: • Although fructose malabsorption is believed to be related with chronic abdominal pain, high-quality evidence is lacking. • Concerns have raised regarding the use of breath hydrogen test for fructose malabsorption in children with chronic abdominal pain. What is New: • Fructose malabsorption is not more common in children with pain-predominant functional gastrointestinal disorders than in asymptomatic children. • Improvement in symptoms with low-fructose diet may indicate that, although patients with pain-predominant functional gastrointestinal disorders did not have a higher percentage of malabsorption, they had greater fructose intolerance.

Zinc and skin: an update.

The essential trace element zinc (Zn) plays a key role in the development, differentiation and growth of various human tissues. Zinc homeostasis is primarily regulated by two zinc transporter families (solute-linked carrier families, SLC). Disturbances in zinc metabolism may give rise to disorders that typically manifest themselves on the skin. An autosomal recessive zinc deficiency disorder, acrodermatitis enteropathica is caused by a mutation in the gene coding for the ZIP4 transporter. Due to intestinal malabsorption, affected infants develop clinical signs and symptoms shortly after weaning. Acquired zinc deficiency is a rare but underdiagnosed disorder associated with various etiologies and variable clinical manifestations. Depending on the patient's age, a multitude of causes have to be considered. Given the characteristic periorificial and acral lesions, the clinical diagnosis is usually made by dermatologists. Laboratory confirmation includes measurement of plasma zinc levels and - as a supplementary measure - zinc-dependent enzymes such as alkaline phosphatase. Oral zinc replacement therapy frequently leads to clinical remission within a few days. Depending on the cause, disease management should include cooperation with pediatricians and gastroenterologists in order to guarantee optimal patient care.

A novel NEUROG3 mutation in neonatal diabetes associated with a neuro-intestinal syndrome.

Neonatal diabetes mellitus (NDM) is a rare form of non-autoimmune diabetes usually diagnosed in the first 6 months of life. Various genetic defects have been shown to cause NDM with diverse clinical presentations and variable severity. Among transcriptional factor genes associated with isolated or syndromic NDM, a few cases of homozygous mutations in the NEUROG3 gene have been reported, all mutated patients presenting with congenital malabsorptive diarrhea with or without diabetes at a variable age of onset from early life to childhood. Through a targeted next-generation sequencing assay for monogenic diabetes genes, we aimed to search for pathogenic deleterious mutation in a Turkish patient with NDM, severe malabsorptive diarrhea, neurointestinal dysplasia and other atypical features. In this patient, we identified a novel homozygous nonsense mutation (p.Q4*) in NEUROG3. The same biallelic mutation was found in another affected family member. Of note, the study proband presents with abnormalities of the intrahepatic biliary tract, thyroid gland and central nervous system, which has never been reported before in NEUROG3 mutation carriers. Our findings extend the usually described clinical features associated with NEUROG3 deficiency in humans, and question the extent to which a complete lack of NEUROG3 expression may affect pancreas endocrine function in humans.

Demographic and Clinical Correlates of Mucosal Disaccharidase Deficiencies in Children With Functional Dyspepsia.

BACKGROUND: A subset of children with functional gastrointestinal disorders (FGIDs), which includes functional dyspepsia, may have duodenal disaccharidase deficiencies. OBJECTIVES: To determine the frequency, demographics, and clinical characteristics associated with duodenal disaccharidase deficiencies in children with functional dyspepsia. METHODS: Children ages 4 to 18 years undergoing esophagogastroduodenoscopy (EGD) evaluation for dyspepsia were enrolled in either a retrospective (study 1) or prospective (study 2) evaluation. Those with histologic abnormalities were excluded. Duodenal biopsies were obtained for disaccharidase enzyme analysis. In the retrospective study, both demographic and clinical characteristics were obtained via chart review. In the prospective study, parents completed the Rome II Questionnaire on Gastrointestinal Symptoms before the EGD. RESULTS: One hundred and twenty-nine children (n = 101, study 1; n = 28, study 2) were included. Mean age was 11.2 ±â€Š3.8 (SD) years in study 1 and 10.6 ±â€Š3.2 years in study 2. Forty-eight (47.5%) of subjects in study 1 and 13 (46.4%) of subjects in study 2 had at least 1 disaccharidase deficiency identified. All of those with a disaccharidase deficiency in both studies had lactase deficiency with 8 (7.9%) and 5 (17.9%) of those in studies 1 and 2, respectively, having an additional disaccharidase deficiency. The second most common disaccharidase deficiency pattern was that of pan-disaccharidase deficiency (PDD) in both studies. In study 1 (where both race and ethnicity were captured), self-identified Hispanic (vs non-Hispanic, P < 0.05) and non-white (vs white, P < 0.01) children were more likely to have lactase deficiency. Age, sex, and type of gastrointestinal symptom were not associated with presence or absence of a disaccharidase deficiency. CONCLUSIONS: Approximately half of children with functional dyspepsia undergoing EGD were identified as having a disaccharidase deficiency (predominantly lactase deficiency). Race/ethnicity may be associated with the likelihood of identifying a disaccharidase deficiency. Other clinical characteristics were not able to distinguish those with versus without a disaccharidase deficiency.