5 Key Takeaways

• 1

  Two male littermate cats, Gary and Shaggy, had displaced eye lenses, unusually long limbs, and severe aortic enlargement consistent with Marfan syndrome.

• 2

  Whole-genome sequencing identified the same rare FBN1 variant in both cats, which was absent from genomic data for more than 1,000 other cats.

• 3

  Both cats inherited two copies of the variant, but long-read RNA sequencing showed that it did not completely disable FBN1.

• 4

  Approximately 73% of the affected cat’s FBN1 transcripts lacked exon 22, while the remaining transcripts retained it and may allow some normal fibrillin-1 production.

• 5

  The authors noted that the study involved only two related cats and did not directly analyze fibrillin-1 protein production.