Gonadal dysgenesis

From Dog

Gonadal dysgenesis syndrome (Xo syndrome, Turner syndrome) is a rare dvelopmental abnormality of dogs characterized by chromosomal abnormalities and quiescent ovarian function.

In the few reported cases, affected bitches had abnormal oestrus cycle and apparently persistent follicles.

A breed predisposition has been reported in the Poodle and Doberman[1].

No other phenotypic abnormalities were reported, unlike human patients which show a number of physical changes with this condition.

Karyotyping usually reveals XX-XO mosaicism (some chromosomes are entirely missing the additional X chromosome)[2].


  1. Smith FW et al (1989) X-chromosomal monosomy (77,X0) in a Doberman Pinscher with gonadal dysgenesis. J Vet Intern Med 3(2):90-95
  2. Mayenco-Aguirre AM et al (1999) Canine gonadal dysgenesis syndrome: a case of mosaicism (77,XO-78,XX). Vet Rec 145(20):582-584