Hereditary macrostomus in the rabbit: a model for Treacher Collins syndrome, one form of mandibulofacial dysostosis.

Macrostomus in the rabbit was diagnosed externally by the presence of papillae at the corners of the mouth. Internally the effect is on the zygomatic complex and is extremely variable. Inheritance appears to be due to a single autosomal recessive gene with incomplete penetrance. We propose the symbol mst for the gene responsible for this condition. Evidence is presented to suggest that this gene is very likely in linkage group IV. Macrostomus in the rabbit is a model for the Treacher Collins syndrome, one form of mandibulofacial dysostosis in humans.