DGAT1 mutation is linked to a congenital diarrheal disorder

Congenital diarrheal disorders (CDDs) are a collection of rare, heterogeneous enteropathies with early onset and often severe outcomes. Here, we report a family of Ashkenazi Jewish descent, with 2 out of 3 children affected by CDD. Both affected children presented 3 days after birth with severe, intractable diarrhea. One child died from complications at age 17 months. The second child showed marked improvement, with resolution of most symptoms at 10 to 12 months of age. Using exome sequencing, we identified a rare splice site mutation in the DGAT1 gene and found that both affected children were homozygous carriers. Molecular analysis of the mutant allele indicated a total loss of function, with no detectable DGAT1 protein or activity produced. The precise cause of diarrhea is unknown, but we speculate that it relates to abnormal fat absorption and buildup of DGAT substrates in the intestinal mucosa. Our results identify DGAT1 loss-of-function mutations as a rare cause of CDDs. These findings prompt concern for DGAT1 inhibition in humans, which is being assessed for treating metabolic and other diseases.

A survey on clinical presentation and nutritional status of infants with suspected cow' milk allergy

BACKGROUND

Cow's milk is the most common food allergen in infants and the diagnosis of cow's milk allergy is difficult, even with the use of several diagnostic tests. Therefore, elimination diets and challenge tests are essential for the diagnosis and treatment of this disorder. The aim of this study is to report the clinical presentation and nutritional status of children evaluated by pediatric gastroenterologists for the assessment of symptoms suggestive of cow's milk allergy.

METHODS

An observational cross-sectional study was performed among 9,478 patients evaluated by 30 pediatric gastroenterologists for 40 days in 5 different geographical regions in Brazil. Clinical data were collected from patients with symptoms suggestive of cow's milk allergy. The nutritional status of infants (age < or = 24 months) seen for the first time was evaluated according to z-scores for weight-for-age, weight-for-height, and height-for-age. Epi-Info (CDC-NCHS, 2000) software was used to calculate z-scores.

RESULTS

The prevalence of suspected cow's milk allergy in the study population was 5.4% (513/9,478), and the incidence was 2.2% (211/9,478). Among 159 infants seen at first evaluation, 15.1% presented with a low weight-for-age z score (< -2.0 standard deviation - SD), 8.7% with a low weight-for-height z score (< -2.0 SD), and 23.9% with a low height-for-age z score (< -2.0 SD).

CONCLUSION

The high prevalence of nutritional deficits among infants with symptoms suggestive of cow's milk allergy indicates that effective elimination diets should be prescribed to control allergy symptoms and to prevent or treat malnutrition.

[Acute diarrhea in children less than 3 years of age: Enteropathogens isolated in patient's stools, compared with a control group]

OBJECTIVES: To observe the occurrence of different etiological agents of acute diarrhea (AD) in stool specimens of patients and children in a control group. MATERIAL AND METHODS: 100 children less than three years of age with AD were studied as well as 100 controls, between November 1993 and May 1994. Stool specimens were collected in both groups and the following enteropathogens were searched for: Rotavirus, Escherichia coli (EPEC, ETEC, EIEC, EHEC), Salmonella sp, Shigella sp, Campylobacter jejuni, Campylobacter coli, Yersinia enterocolitica, Cryptosporidium sp, Giardia lamblia, Entamoeba histolytica. Statistical analysis using the exact Fisher test (at significance level p<0,05) was done. The mean age was 12,5 months, with more cases in patients less than 6 months (35%). Children were seen at the emergency section on an average fifth day after the start of the diarrhea. Most came from homes with basical sanitary conditions. Watery diarrhea was more frequent than bloody diarrhea with mucus, at a proportion of 4:1. RESULTS: Rotavirus was the most frequent agent: 21% in the AD group and 3% in the control group (p= 0,0001). Shigella sp was isolated in 7% of the AD group and none of the control group (p= 0,0140). EPEC was detected in 13% of AD cases and 7% in the control group (p= 0,2381) but the classical subgroups O55, O111, O119 were only isolated from the patients with AD. The other enteropathogens were infrequently detected or in equal proportion in both groups. Rotavirus and EPEC were the more frequently isolated agents in watery diarrhea, while Shigella sp was the predominant agent found in bloody stools with mucus. CONCLUSIONS: Rotavirus was the most common causative agent in AD. The detection of Rotavirus and Shigella sp nearly exclusively in patients with AD confirms the high patogenicity of these etiological agents when compared to the others. Escherichia coli (EPEC) diagnosed by polyvalent sera does not confirm its respective diarrheogenic property due to isolation in the same proportion among patients with AD and controls. Monovalent antisera made possible the detection of classical subgroups of EPEC O111, O119, O55 isolated only from AD patients, confirming the already known high patogenicity of these strains.

[Peptic disease: comparative study between children and adolescents]

OBJECTIVES: To make a comparative analysis of clinical and endoscopic data in peptic disease in a group of children (CR) and adolescents (AD).MATERIAL AND METHODS: 30 children and 76 adolescents with peptic disease were studied between August 1992 and November 1994. In all cases the diagnosis was confirmed by endoscopic and histologic examination. Clinical data referring abdominal pain (localization, degree of intensity, chronicity and related symptons) were compared in both groups. Statistical analysis was done by the Fisher Test (significance value p< 0.05).RESULTS: Findings referring to predominance in the female sex (66% in group CR versus 70% in group AD), duration of pain between 2 and 6 months (40% CR versus 38% AD), intensive degree of pain (70% CR versus 83% AD) and presence of vomiting and nausea (42% CR versus 55% AD) were similar in both groups. Epigastric pain was predominant in AD (87%) versus CR (63%) with significant difference p=0.012. The endoscopic findings were normal in 30% of CR and 14% AD (p=0.052). Light to moderate gastritis was significantly more common in AD (72%) than CR (37%) (p=0.01). In the CR group, there was mainly antral nodular gastritis while in AD the diffuse form was more frequent. Bulbar duodenitis was present in 10% CR and 12% AD, but it was more erosive and serious in children. Peptic ulceration was found in 16% of CR (2 gastritis and 3 duodenal) and 7% AD (1 gastric and 4 duodenal) (p=0.067). H. pylori colonization was more frequent in AD (52%) than in CR (36%) (p=0.195).CONCLUSIONS: 1) epigastric pain is the main symptom in both groups; 2) endoscopic findings may be normal especially in the childreńs group; 3) antral nodular gastritis is the predominant type in children while in adolescents it is diffuse gastritis; 4) H. pylori colonization is present in 1/3 of children and 1/2 of adolescents with peptic disease; 5) in both groups ulcers are more frequent in the duodenum.