First DNA Test for Equine Turner Syndrome Now Available
07.08.2025
generatio is expanding its range of genetic tests for horses with a new, innovative DNA test for Equine Turner Syndrome (eTS) – a chromosomal disorder in mares that has been difficult to diagnose until now. The new test enables easy and reliable diagnosis from a hair root sample for the first time. The absence of an X chromosome is the most common chromosomal abnormality in horses.
The Turner syndrome is caused by the absence of one of the two X chromosomes or at least the essential parts of it. The symptoms only become apparent when the horse reaches sexual maturity: Affected mares often have underdeveloped ovaries, an indistinct or immature uterus, are usually infertile, and may also have a smaller physique and poorly developed secondary sexual characteristics. Despite these limitations, they can usually lead a normal life.
Until now, diagnosis was only possible through complex karyotyping. The new DNA test now offers a practical alternative that can also be used in routine diagnostics – for example, as part of a pre-purchase examination or when investigating infertility.
Until now, diagnosis was only possible through complex karyotyping. The new DNA test now offers a practical alternative that can also be used in routine diagnostics—for example, as part of a purchase examination or when investigating infertility.
In humans, the incidence is 1 in 2,500. No studies on the incidence in horses have been conducted to date. However, it is suspected that eTS of the X chromosome is an underestimated cause of infertility in mares due to the lack of simple diagnostic options to date.
Early detection of Turner syndrome helps breeders and veterinarians to better assess expectations regarding a mare's suitability for breeding and development.