Cornell scientists identify rare human genetic disorder in two unusually long-legged cats
Two unusually long-legged cats have helped scientists uncover the first genetically confirmed cases of Marfan syndrome in domestic felines. Researchers at Cornell University discovered that the brothers carried two altered copies of a gene linked to the rare connective tissue disorder, which can affect the eyes, heart, and blood vessels. Surprisingly, the cats survived into adulthood because their genetic mutation…
Key points
- Cornell researchers documented the first molecular case of Marfan syndrome in domestic cats.
- Brothers Gary and Shaggy each inherited two altered copies of the FBN1 gene.
- Their variant left some gene function intact, likely helping them survive to adulthood.
Cornell University researchers have reported the first molecular characterization of Marfan syndrome in domestic cats, according to a study published in Scientific Reports. The subjects were two brothers, Gary and Shaggy, who drew attention as kittens for their unusually long limbs.
Veterinarians later found abnormalities in the cats' eye structures and an enlarged aorta, the body's main artery. Together these signs pointed to Marfan syndrome, an inherited condition that weakens connective tissue and affects about 1 in 4,000 people. The brothers were the first known documented feline cases.
What the DNA showed
Researchers from several disciplines examined the cats and analyzed their DNA. They identified changes in a gene called FBN1, which carries instructions for making fibrillin-1, a protein needed for healthy connective tissue supporting blood vessels, bones, ligaments, skin and eyes.
Testing showed Gary and Shaggy each had two altered copies of FBN1, one inherited from each parent. In humans, a mutation in only one copy can cause Marfan syndrome, so two altered copies is exceptionally uncommon and can severely disrupt normal fibrillin-1 production.
The findings provide a foundation for improved veterinary diagnostics
— Dr. Jacquelyn Evans
Why the cats survived
Further analysis found the brothers' variant did not fully disable the gene. It interfered with how the gene's instructions were processed while still permitting some normal activity, which helps explain how the cats reached adulthood despite carrying two copies of the mutation.
What researchers said
Senior author Dr. Jacquelyn Evans, an assistant professor in the College of Veterinary Medicine and at the Baker Institute for Animal Health, said the findings offer a basis for better veterinary diagnostics and may aid the development of genetic tests.
