Male Pseudohermaphroditism of the Testicular Feminizing Type in a Horse

Abstract

SUMMARY Features characteristic of the hereditary syndrome of testicular feminization (tfm) were observed in a 7‐year‐old Quarter Horse. The horse had female body habitus and male psychosexual behaviour. Gonads located in the abdomen were testes and the uterus and cervix were absent. The vagina was normal in depth but ended as a blind pocket. The sex chromosome composition of testicular fibroblast and leucocyte cultures was XY. Construction of a family pedigree revealed a pattern of hereditary transmission similar to that reported for tfm in other mammalian species. RÉSUMÉ Des caractères d'un syndrome héréditaire de féminisation testiculaire furent constatés chez un cheval de Selle de 7 ans. Ce cheval avait un comportement psychique de mâle et un aspect de jument. Les gonades se trouvaient dans l'abdomen. L'utérus et le cervix n'existaient pas. Le vagin était normal mais se terminait en cul de sac. Les chromosomes sexuel du tissu testiculaire et des leucocytes étaient de type XY. L'étude du pedigree revela des traits génétiques comparables à ceux relevés pour le même syndrome hezc d'autres mammifères. ZUSAMMENFASSUNG Die charakteristischen Merkmale des hereditären Syndroms der testikulären Verweiblichung konnte bei einem 7 jährigen Quarter Horse beobachtet werden. Das Pferd zeigte einen Stutenhabitus und ein männliches Sexualverhalten. Die abdominal gelegenen Gonaden erwiesen sich als Hoden; Uterus und Cervix fehlten. Die Vagina war von normaler Länge, endete aber als Blindsack. Die Geschlechtschromosomen testikulärer Fibroblasten und von Leukocytenkulturen bestanden aus XY. Ein Familienstammbaum Hess auf einen Erbgang schliessen, wie er auch bei anderen Säugetierarten beschrieben worden ist.

Equine Disorders of Sexual Development in 17 Mares Including XX, <i>SRY</i>-Negative, XY, <i>SRY</i>-Negative and XY, <i>SRY</i>-Positive Genotypes

“…Over the last 3 decades, the equine sex reversal syndrome has been a subject of several publications although most often relating to mares having primary infertility. After cytogenetic investigations a normal stallion karyotype was found, but there was phenotypic heterogeneity [Chandley et al, 1975;Kieffer, 1976;Long, 1988;Power, 1986]. The phenotype of XY mares ranges from individuals with normal female external genitalia, but undeveloped gonads, to females with external sexual ambiguity due to different degrees of virilization and hypoplastic gonads [Kent et al, 1986[Kent et al, , 1988.…”

“…The phenotype of XY mares ranges from individuals with normal female external genitalia, but undeveloped gonads, to females with external sexual ambiguity due to different degrees of virilization and hypoplastic gonads [Kent et al, 1986[Kent et al, , 1988. Studies of several horse breeds with this syndrome have led to the proposal of not only X-linked genes but also an autosomal type of inheritance [Kieffer, 1976;Kent et al, 1986]. More recent investigations of the equine XY DSD syndromes, assessing the analysis of DNA sequences for the SRY locus of the Y-chromosome, have led to the description of 2 main types of the XY DSD: mares with normal stallion karyotypes but undetectable DNA sequences for the SRY gene ( SRY -negative); and mares that are XY and SRY -positive [Pailhoux et al, 1995;Bugno et al, 2003;Switonski et al, 2005;Kuiper and Distl, 2007].…”

Equine clinical cytogenetics: the past and future

“…The differences in phenotype may reflect the type of genetic abnormality that is present. Familial patterns of inheritance have been described, particularly in certain Arabian horse sire lines (Kieffer et al, 1976;Kent et al, 1986;Bowling et al, 1987). Molecular testing of these horses may identify a deletion of or a non-functional SRY gene (Pailhoux et al, 1995;Abe et al, 1999;Mäkinen et al, 1999;Bugno et al, 2003).…”

Sex reversal syndrome in a five year old Friesian horse

“…64,XY/SRY-positiv (Switonski et al 2005), 64,XX/SRY-negativ (Meyers-Wallen et al 1997, Bouen et al 2000, 64,XX/64,XY (Dunn et al 1981), 63,X0/64,XY (Dunn et al 1981), 63,X0/64,XXY (Herzog et al 1989) oder 64,XX-65,XXY (Bounters et al 1972(Bounters et al , 1975. Eine erbliche Komponente wird diskutiert (Kieffer et al 1976, Kent et al 1986, Trommershausen-Bowling et al 1987, Bouen et al 2000, Kuiper 2001. Für das Sex Reversal Syndrom wird ein autosomal rezessiver Erbgang angenommen (Kuiper und Distl 2007).…”

“…Unterschiedliche Fälle von Pseudohermaphroditismus sind bei einem Quarter-Horse (Kieffer et al 1976), einem AraboHaflinger (Braun et al 1984), beim Warmblut (Göbel und Köhne 1994, Bartmann und Lorber 2003, Mayer et al 2004, bei einem Appaloosa (Milliken et al 1995) …”