Monarch Disease Ontology identifier MONDO_0020505 (ravine syndrome) is an extremely rare genetic neurological disorder, reported in a small number of patients in a specific community on Reunion Island (Ravine region), characterized by infantile anorexia with irrepressible and repeated vomiting, acute brainstem dysfunction, severe failure to thrive, and progressive encephalopathy with MRI showing vanishing of medulla oblongata and cerebellar white matter and severe atrophy of pons, along with supra-tentorial periventricular white-matter hyperintensities and basal ganglia anomalies. Also known as: Reunion island-anorexia-vomiting which is irrepressible-neurological signs syndrome, progressive encephalopathy with severe infantile anorexia.