Ann. Méd. Vét., 2003, 147 (5), pp 359 - 364 Overo lethal white syndrome -- two case reports and a review of the literatureSandersen C., Delguste C., Cassart D., Grulke S., Guyot H., Amory H.Abstract :
« Overo lethal white syndrome» is an inherited anomaly of white foals born to overo-coloured parents. All the affected foals die within a few days after birth form complications due to an intestinal aganglionosis. This report describes two cases of foals which were presented to our clinic and which showed clinical signs and necropsy lesions typical for this syndrome. Both foals had a white coat colour and were born to an overo-coloured dam. They appeared perfectly normal at birth, but were unable to eliminate meconium and show signs of colic that did not respond neither to analgesic treatment nor to enemas. Both foals were euthanized. At necropsy, small intestinal distension, impaction of meconium
located in caecum and large colon, and a small and empty small colon were found. OLWS affected foals suffer from absence of myenterical nerve complexes in the caecum, colon and smali colon, resulting in an absence of intestinal peristalsis responsible for clinical signs suggestive of intestinal obstruction. Affected foals are homozygous for a mutation of the «endothelin B receptor» gene. The endothelin B-signaling pathway is critical for the proper development and migration of neuronal crest cells that ultimately form melanocytes and enteric neurons. Get the PDF Contact person : Charlotte.sandersen@ulg.ac.be |