Turner's Syndrome

Aetiology

• Occurs in Mares
• X0 sex chromosome complement
• Normal autosomal chromosome complement
• Develop an ovary
• There is only one active X chromosome, so Oocytes die.
• The death of Oocytes is followed by loss of follicles.
• This leads to Ovarian Dysgensis (abnormal development) and a highly regressed Streaky Ovary that does not secrete the normal ovarian steroid hormones.
• The Ovary therefore lacks tone and has no follicular cycles.

Morphology

• Normal external genetalia
• Small stature
• Flaccid Uterus
• Small, inactive Ovaries
• Complete absence of Ovarian activity and consequent Anoestrous