INTOLERÂNCIA HEREDITÁRIA À FRUTOSE: ETIOLOGIA E PRINCIPAIS CARACTERÍSTICAS CLÍNICAS, UMA REVISÃO DE LITERATURA

Abstract

INTRODUCTION: Fructose is a monosaccharide found in various plant sources, honey, and fruits, as well as composing sucrose. After consumption, fructose absorption is facilitated by glucose transporters and metabolized in the liver, small intestine, and kidneys, where enzymes catalyze the breakdown of this monosaccharide. Hereditary Fructose Intolerance results from mutations in the ALDOB gene, which encodes the enzyme aldolase B, the primary enzyme involved in fructose metabolism, thus intolerance is a result of deficiency of this enzyme. OBJECTIVES: To review the etiological factors of Hereditary Fructose Intolerance, its main symptoms, and the treatment that should be performed. METHODOLOGY: Narrative literature review in biochemistry and genetics textbooks and in electronic databases (PubMed, Orphanet, Google Scholar, and Scielo) between July and September 2023. RESULTS: Hereditary Fructose Intolerance, estimated to have a prevalence of 1/40,000 in Europe, consists of aldolase B deficiency, responsible for fructose catabolism. Caused by genetic mutations, enzyme coding is affected, leading to the accumulation of fructose-1-phosphate in the liver, kidneys, and small intestine, which is harmful to these organs. Symptoms include nausea, vomiting, diarrhea, abdominal pain, flatulence, and hypoglycemia. Hepatic inflammation, renal overload, and tubular reabsorption difficulty also occur. It is noted that symptoms are not manifested in infants, as they usually occur during dietary diversification when foods containing fructose are ingested. CONCLUSION: Since it is a result of genetic mutations, there is no effective treatment as in the case of lactose intolerance, where aldolase B is not available in capsule form like lactase. Therefore, treatment involves dietary restriction of fructose, sucrose, sucralose, and sorbitol, with supplementation of essential vitamins present in foods containing these compounds being necessary. If left untreated, it can result in renal failure, metabolic acidosis, hepatic cirrhosis, coma, and death.