Scientists Find Genes Behind Crooked Legs in Shetland Ponies

A hereditary disease–skeletal atavism–leads to disturbed skeletal development and usually requires euthanasia.

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Crooked legs in Shetland ponies often result from a hereditary disease that leads to disturbed skeletal development and usually requires euthanasia. As such, the condition can cause major problems for Shetland breeding farms. But new genomic research has finally identified the responsible genes, a finding that could ultimately eliminate the disease’s presence altogether.

“Our study has allowed us to discover the exact locations of the responsible mutations in the horse genome,” said Carl-Johan Rubin, PhD, of the Science for Life Laboratory in the Department of Medical Biochemistry and Microbiology at Uppsala University, in Sweden.

“Our hope now is that breeders will use this knowledge to get their breeding stock tested, so that no new individuals ever have to be born with this debilitating condition,” he told The Horse.

The condition, known by scientists as “skeletal atavism,” causes the radius and ulna and/or the tibia and fibula (in the front and hind legs, respectively) to develop as separate bones, whereas in modern adult equids, these two bones are fused together, Rubin said

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Passionate about horses and science from the time she was riding her first Shetland Pony in Texas, Christa Lesté-Lasserre writes about scientific research that contributes to a better understanding of all equids. After undergrad studies in science, journalism, and literature, she received a master’s degree in creative writing. Now based in France, she aims to present the most fascinating aspect of equine science: the story it creates. Follow Lesté-Lasserre on Twitter @christalestelas.

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