A case of ambiguous external genitalia in a Thoroughbred male horse with the 63,XO/64,XY mosaic karyotype.
A Thoroughbred colt with ambiguous external genitalia was presented for clinical and histological examinations. The colt had a short penis that faced backward between his hind limbs. The measurements of luteinizing hormone, follicle stimulating hormone, testosterone and ir-inhibin showed a tendency to increase gradually from April. Both the sex-determining region of the Y chromosome and amelogenin gene fragments were detected by the PCR method. A cytogenetic analysis revealed the 63,XO/64,XY mosaic karyotype (ratio 83:17). In autopsy, immature symmetrical subcutaneous testes were found in the inguinal regions. The testes and other accessory sex organs were histologically normal. These results add to our knowledge of chromosomal abnormality and information concerning disorders of sex development in the horse.
Hidaka Training and Research Center, Japan Racing Association, 535-13 Nishicha, Urakawa, Hokkaido, Japan. Fumio_Sato@jra.go.jp
Fumio
F
Sato
Keiichi
K
Hirota
Teruaki
T
Tozaki
Katsumi
K
Ito
Pramod
P
Dhakal
Kazuyoshi
K
Taya
Yoshiro
Y
Endo
Harutaka
H
Murase
Yasuo
Y
Nambo
D053523:Amelogenin / Q000235:genetics; D000818:Animals; D002869:Chromosome Aberrations / Q000662:veterinary*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D012734:Disorders of Sex Development / Q000235:genetics / Q000662:veterinary*; D017809:Fatal Outcome; D005640:Follicle Stimulating Hormone / Q000097:blood; D024282:Genes, sry / Q000235:genetics; D006736:Horses / Q000002:abnormalities* / Q000235:genetics*; D007265:Inhibins / Q000097:blood; D007621:Karyotyping / Q000662:veterinary; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013739:Testosterone / Q000097:blood
D053523:Amelogenin; D013739:Testosterone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D004247:DNA