title: SRY negative 64,XX intersex phenotype in an American saddlebred horse.
abstract: A female American saddlebred horse was presented for surgical correction of a possible pseudohermaphrodite condition. The horse had abnormal external genitalia and exhibited stallion-like behaviour. No evidence of uterine or ovarian tissue was identified on laparoscopic examination, but hypoplastic testicular-like tissue was removed, although this was found to contain no spermatogonia upon histopathological examination. A karyotype was performed and showed the normal chromosomal complement for a female horse (64,XX). Polymerase chain reaction to detect the SRY gene was negative in peripheral blood as well as the testicular-like tissue. This case represents the first report of an SRY negative XX-male sex reversal intersex phenotype, which is a potentially inherited condition, in an American saddlebred horse.
authors.affiliation: Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. dlbannasch@ucdavis.edu
authors.forename: D
authors.initials: D
authors.lastname: Bannasch
authors.forename: C
authors.initials: C
authors.lastname: Rinaldo
authors.forename: L
authors.initials: L
authors.lastname: Millon
authors.forename: K
authors.initials: K
authors.lastname: Latson
authors.forename: T
authors.initials: T
authors.lastname: Spangler
authors.forename: S
authors.initials: S
authors.lastname: Hubberty
authors.forename: L
authors.initials: L
authors.lastname: Galuppo
authors.forename: L
authors.initials: L
authors.lastname: Lowenstine
mesh_terms: D000818:Animals; D012734:Disorders of Sex Development / Q000175:diagnosis / Q000662:veterinary*; D005260:Female; D005835:Genitalia / Q000002:abnormalities; D006734:Horse Diseases / Q000175:diagnosis* / Q000235:genetics; D006736:Horses / Q000235:genetics* / Q000502:physiology*; D007621:Karyotyping; D010641:Phenotype; D012733:Sex Differentiation; D051876:Sex-Determining Region Y Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D051876:Sex-Determining Region Y Protein