title: [Clinical evaluation of the new coat colour macchiato in a male Franches-Montagnes horse].
abstract: In April 2008 a Franches-Montagnes colt was born with an unusual coat colour phenotype which had never been observed in that population before. The foal showed extended white markings on body and legs, a white head and blue eyes. As both parents have an unremarkable bay coat colour phenotype, a de novo mutation was expected in the offspring and a candidate gene approach revealed a spontaneous mutation in the microphthalmia associated transcription factor gene (MITF). A detailed clinical examination in 2010 indicated an impaired hearing capacity. As in the American Paint Horse large white facial markings in combination with blue eyes are associated with deafness, the hearing capacity of the stallion was closer examined performing brainstem auditory-evoked responses (BAER). The BAER confirmed bilateral deafness in the Franches-Montagnes colt. It is assumed that the deafness is caused by a melanocyte deficiency caused by the MITF gene mutation. Unfortunately, due to castration of the horse, the causal association between the mutation in the MITF gene and clinical findings cannot be confirmed by experimental matings.
authors.affiliation: Institut Suisse de Médicine Equine, ALP-Haras und Universität Bern. marlisblatter@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Blatter
authors.forename: B
authors.initials: B
authors.lastname: Haase
authors.forename: V
authors.initials: V
authors.lastname: Gerber
authors.forename: P-A
authors.initials: PA
authors.lastname: Poncet
authors.forename: T
authors.initials: T
authors.lastname: Leeb
authors.forename: S
authors.initials: S
authors.lastname: Rieder
authors.forename: D
authors.initials: D
authors.lastname: Henke
authors.forename: F
authors.initials: F
authors.lastname: Janett
authors.forename: D
authors.initials: D
authors.lastname: Burger
mesh_terms: D000818:Animals; D003638:Deafness / Q000235:genetics / Q000662:veterinary*; D016057:Evoked Potentials, Auditory, Brain Stem; D005127:Eye Color / Q000235:genetics; D006200:Hair Color / Q000235:genetics*; D006734:Horse Diseases / Q000235:genetics*; D006736:Horses / Q000033:anatomy & histology / Q000235:genetics*; D008297:Male; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics*; D009154:Mutation
chemical_list: D051739:Microphthalmia-Associated Transcription Factor