ESPE Abstracts

Introduction: Abetalipoproteinemia is a rare genetic disease with autosomal recessive inheritance, caused by biallelic mutations in the microsomal triglyceride transfer protein (MTTP) gene¹. Its worldwide prevalence is estimated at 1:1,000,000², with approximately 100 cases reported in the literature³. Epidemiological data on this pathology in Brazil are not found in the literature.

Case Report: J.O.S.C, a 2-year-old male, born full-term with APGAR scores of 9/9, weighing 3785g (AGA). He presented daily vomiting with milk content since 10 days of age, associated with cough. Despite initial treatment with domperidone, esomeprazole, and bromopride, symptoms persisted. At 1 month and 18 days, he was hospitalized due to severe dehydration from frequent vomiting and decreased diuresis. During hospitalization, the introduction of amino acid formula reduced vomiting to once daily. The patient was referred to a pediatric gastroenterologist, and tests showed normal esophagogram and positive fecal fat analysis. Attempt to perform sweat test was unsuccessful. At 5 months, he began passing mucous, but no blood, in stools. At 7 months, the formula was switched to lactose-free protein hydrolysate, reducing vomiting frequency (from daily to 2-3 times per week), but mucous persisted in stools and weight gain remained low. With increasing suspicion of an underlying metabolic condition, genetic studies identified mutations in the microsomal triglyceride transfer protein (MTTP) gene, confirming the diagnosis of abetalipoproteinemia at 8 months of age.

Discussion: The absence of apoB-containing lipoproteins and deficient absorption of fat-soluble vitamins cause the multisystem clinical manifestations observed in affected individuals. The gastrointestinal profile is characterized by malabsorptive syndrome, with steatorrhea being the most prominent feature³. Symptoms such as vomiting, abdominal pain, and distension worsen with the intake of fatty foods, including breast milk. The recurrence of these symptoms quickly leads to the failure to thrive observed in these patients³,⁴.

Conclusion: This case illustrates the challenges in the diagnosis and management of abetalipoproteinemia, a rare and complex metabolic condition. The diagnostic approach relied on detailed history taking, comprehensive laboratory investigation, and specific genetic analysis. Therapeutic management focused on correcting nutritional deficiencies and multidisciplinary support to optimize clinical outcomes and patient quality of life. Early identification and appropriate treatment are crucial to mitigate long-term complications associated with this devastating condition.