Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE) is a rare autosomal recessive disorder caused by mutations in the gene encoding the Thymidine Phosphorylase (TP). It is clinically characterized by severe gastrointestinal dysmotility, cachexia, palpebral ptosis, ophthalmoparesis, sensorimotor polyneuropathy and leukoencephalopathy. The diagnosis is established by the presence of typical clinical and neuroimaging features, positive family history, and abnormal genetic test. A 19-year-old Cape Verdean patient with a history since childhood of recurrent episodes of nausea, vomiting, diarrhoea and painful abdominal distension associated with progressive motor disability with difficulty in climbing stairs and running and clumsiness with her hands. The diagnostic workup was suggestive of MNGIE. Genetic screening of the TYMP gene identified a novel mutation (c. 1283 G>A). Patients with MNGIE have significant comorbidity and mortality, and they are frequently misdiagnosed. A better acknowledgment of this disorder is essential to permit an earlier diagnosis and to improve disease management.