RESUMO
Hereditary fructose intolerance (HFI) is an inborn error of fructose metabolism of autosomal recessive inheritance caused by pathogenic variants in the ALDOB gene that lead to aldolase B deficiency in the liver, kidneys, and intestine. Patients manifest symptoms, such as ketotic hypoglycemia, vomiting, nausea, in addition to hepatomegaly and other liver and kidney dysfunctions. The treatment consists of a fructose-restricted diet, which results in a good prognosis. To analyze the distribution of ALDOB variants described in patients and to estimate the prevalence of HFI based on carrier frequency in the gnomAD database, a systematic review was conducted to assess ALDOB gene variants among patients with HFI. The prevalence of HFI was estimated from the carrier frequency of variants described in patients, as well as rare variants predicted as pathogenic by in silico tools. The p.(Ala150Pro) and p.(Ala175Asp) variants are the most frequent and are distributed worldwide. However, these variants have particular distribution patterns in Europe. The analysis of the prevalence of HFI showed that the inclusion of rare alleles predicted as pathogenic is a more informative approach for populations with few patients. The data show that HFI has a wide distribution and an estimated prevalence of ~1:10,000.
Assuntos
Intolerância à Frutose , Alelos , Intolerância à Frutose/diagnóstico , Intolerância à Frutose/epidemiologia , Intolerância à Frutose/genética , Frutose-Bifosfato Aldolase/genética , Humanos , Fígado/patologia , MutaçãoRESUMO
ABSTRACT: Fructose is a highly abundant carbohydrate in western diet and may induce bowel symptoms in children as in adults. The main objective of this study is to describe the frequency of fructose malabsorption (FM) in symptomatic patients 18 years or younger undergoing fructose breath test in a single tertiary center between 2013 and 2018, and to evaluate whether certain symptoms are related to positivity of the test. Out of 273 tests 183 (67%) were compatible with FM. The most frequent pretest symptom in the overall study population was bloating (83%), followed by abdominal pain (73%). Patients with positive test were younger than those with a negative test (median 5 vs 8 years, Pâ<â0.001). In multivariate analysis, which included age, sex, and symptoms (diarrhea, abdominal pain, bloating, nausea), only age <6âyears (odds ratio 2.93, 95% confidence interval 1.64-5.23) and absence of nausea (odds ratioâ=â3.32, 95% confidence interval 1.56-7.05) were associated with FM.
Assuntos
Intolerância à Frutose , Síndromes de Malabsorção , Dor Abdominal , Adulto , Testes Respiratórios , Criança , Chile/epidemiologia , Frutose/efeitos adversos , Intolerância à Frutose/diagnóstico , Intolerância à Frutose/epidemiologia , Humanos , Síndromes de Malabsorção/diagnóstico , Síndromes de Malabsorção/epidemiologia , Síndromes de Malabsorção/etiologia , Centros de Atenção TerciáriaRESUMO
INTRODUCTION: Recently it has been reported that prevalence of fructose intolerance (FI) in patients with functional gastrointestinal disorders range between 38% -75%. OBJECTIVE: To determine the prevalence of FI in subjects diagnosed with irritable bowel syndrome (IBS). METHODS: We studied 25 subjects (17 women, average age 36 years) with IBS (Rome II) and 25 healthy controls (14 women, mean age 37 years) who underwent a breath test after oral loading with fructose (Gastrolyzer ®, Bedfont Scientific Ltd., UK). The load consisted of 25 grams of fructose dissolved in 250 ml of water (10% solution). Breath test analysis of the particles per million (ppm) of hydrogen exhaled were performed every 15 minutes for 3 hours. The fructose breath test was considered positive when concentrations of hydrogen were higher than at 20 ppm or a raising greater than 5 ppm in 3 consecutive samples was detected. RESULTS: According to the Rome II criteria, 10 patients (40%) had IBS-C, 9 (36%) had IBS-D and 6 (24%) had IBS-M. Thirteen (52%) of IBS patients had IF, while only 4 (16%) of control subjects (p = 0.01). Patients with IBS and fructose intolerante tend to suffering from diarrhea predominant IBS (p = 0.053). CONCLUSIONS: Fructose intolerance may be responsible for gastrointestinal symptoms in at least half of IBS patients, especially in the group of patients with IBS-D.