A novel p.Gly417Valfs*12 mutation in the MTTP gene causing abetalipoproteinemia: Presentation of the first patient in Mexico and analysis of the previously reported cases.

BACKGROUND: Our aims were to describe the first Mexican patient with abetalipoproteinemia and to perform a comparative analysis of biochemical, clinical, and genetic characteristics of 100 cases reported in the literature. METHODS: We performed biochemical and molecular screenings in a Mexican girl with extremely low lipid levels and in her family. Further, we integrated and evaluated the characteristics of the cases with abetalipoproteinemia described in the literature. RESULTS: Our patient is a six-year-old girl who presented vomiting, chronic diarrhea, failure to thrive, malabsorption, acanthocytosis, anemia, transaminases elevation, and extremely low lipid levels. MTTP gene sequencing revealed homozygosity for a novel mutation p.Gly417Valfs*12 (G deletion c.1250). With the analysis of the reported cases, 60 clinical features (14 classical and 46 non-classical) were observed, being the most common acanthocytosis (57.5%), malabsorption (43.7%), and diarrhea (42.5%); 48.8% of the patients presented only classic clinical features, while the remaining 51.2% developed secondary effects due to a fat-soluble vitamin deficiency. An odds ratio analysis disclosed that patients diagnosed after 10 years of age have an increased risk for presenting clinical complications (OR = 18.0; 95% CI 6.0-54.1, p < 0.0001). A great diversity of mutations in MTTP has been observed (n = 76, being the most common p.G865X and p.N139_E140) and some of them with possible residual activity. CONCLUSION: The first Mexican patient with abetalipoproteinemia presents a novel MTTP mutation p.Gly417Valfs*12. Three factors that could modulate the phenotype in abetalipoproteinemia were identified: age at diagnosis, treatment, and the causal mutation.

[Efficacy of two Helicobacter pylori eradication treatments in children with recurrent abdominal pain]. / Eficacia de dos esquemas de erradicación de Helicobacter pylori en niños con dolor abdominal recurrente.

OBJECTIVE: To compare clinical and bacteriologic efficacy of two therapeutic trials to eradicate Helicobacter pylori (H. pylori) in two series of pediatric patients with recurrent abdominal pain (RAP). MATERIALS AND METHODS: n = 36 children with RAP-associated H. pylori infection. Age 9.8 +/- 3.1 years, 19 boys and 17 girls. Clinical and bacteriologic efficacy of two therapeutic trials was compared: Group A (1996-1997), n = 9, amoxicillin, bismuth subsalicilate, and metronidazol, and group B (1991-1993), n = 27, omeprazol, amoxicillin, and clarithromycin. Initially and post-treatment, H. pylori evaluation was carried out with upper endoscopy and gastric biopsies. For statistics, we used Student t test, chi2, Fisher test, and Kruskal-Wallis analysis of variance (alpha = 0.05). RESULTS: We found that 33/36 cases had gastritis at endoscopy, two with duodenal ulcer; nodular gastritis was observed in more than one half of total cases. All cases fulfilled histologic criteria of gastritis according to Sydney Score. In group A eradication was achieved in 28.6%, while in group B eradication rose to 77.8% (p < 0.05). In group A, 8/9 and in group B 15/27 persisted with RAP (p = 0.113). CONCLUSIONS: High frequency of abnormal and histologic findings was observed in the series presented on children with RAP and H. pylori. Eradication efficacy in the omeprazol/amoxicillin/clarithromycin group was higher when compared with bismuth subsalicilate/amoxicillin/metronidazol trial. This efficacy is comparable to pediatric series treated with the same therapeutic trial.

Changing trends in prevalence, morbidity, and lethality in persistent diarrhea of infancy during the last decade in Mexico.

BACKGROUND: Persistent diarrhea (PD) of infancy has incurred high morbidity and lethality. However, decrease in its prevalence, morbidity, and lethality appeared to occur progressively throughout the last decade of the twentieth century. Our objective in this study was to compare prevalence, lethality, and morbidity of infants and children with PD managed in a pediatric referral hospital. METHODS: We conducted a comparative cross-sectional study. A total of 546 patients with PD managed during three different periods (1988-1991, 1993-1994, and 1997-1999) were described and analyzed. Prevalence x 100 admissions, prevalence rates of nutritional status, sepsis, pneumatosis intestinalis, carbohydrate and protein intolerance, and lethality were calculated. We used Student t and chi2 tests (alpha = 0.05). RESULTS: Mean age on admission was 13.8 +/- 24.3 months; 296 (54.2%) patients were males. Prevalence of admissions for PD decreased gradually from 31.7 to 13.8%; rates of lethality and mortality remained unchanged. Malnutrition had high prevalence throughout the three periods evaluated. Rate of carbohydrate intolerance diminished but protein intolerance increased; proportion of pneumatosis intestinalis and bowel perforation did not change. Isolation of Salmonella spp. and small bowel bacterial overgrowth decreased significantly from the 1988-1991 series when compared with later series. CONCLUSIONS: Although these observations were made at a pediatric referral hospital, they may suggest that prevalence of PD is diminishing. However, its lethality and mortality rates remain unchanged. Malnutrition persists as a relevant associated factor. Decrease of carbohydrate intolerance and increase in protein intolerance rates resemble rates of children with PD of developed countries. These observations may reflect an epidemiologic transition of PD in Mexico.