[Severe anorexia in infants in Reunion: a new autosomal recessive disease?]

Infantile anorexia is usually considered as a psychogenic disorder with benign prognosis. However, unusually severe characteristics of infantile anorexia, seen in the south of the island, seem to us in favor of a new metabolic etiology.Among 38 known cases, we retrospectively studied the best documented observations of 24 children admitted over the last 25 years to our institution.The sex ratio was ten females and 14 males. Twenty-three of the 24 infants lived in formerly isolated localities of the island where other hereditary diseases have been observed with an unusually high frequency. The family pedigrees favoured an autosomal recessive heredity. Severe anorexia, accompanied by irrepressible vomiting (91%), appeared at the age of 8.5 months +/- 3.5. Parenteral (54.2%) or enteral (54.2%) feeding was necessary but did not always avoid death, which occurred in 45.8% of the cases at the age of 24 months +/- 3.5. All of the children which survived had neurological disorders (pyramidal syndrome, ataxia, laryngeal palsy, mental retardation, seizures) which occurred sometimes at an early stage. The investigations did not allow the identification of any known cause.The elevated level of lactic acid in the cerebral spinal fluid seemed to indicate a possible mitochondrial disorder, eventually a mutation of an autosomal gene of the pyruvate dehydrogenase complex because of the normal lactate/pyruvate ratio, but enzymatic activities were normal. The cerebral MRI showed features of leukodystrophy. On the other hand, the elevated level of plasma serotonin seemed to indicate a disorder of the serotonin metabolism, for which an animal model exists.We propose to name this new syndrome by the acronym 'RAVINE' which associates Reunion, Anorexia, Vomiting which is Irrepressible, and Neurological signs. Linkage study might allow the localization and isolation of a gene and allow one to start understanding the biological mechanism which we suspect to be an hereditary neurobiological eating disorder.