A few years ago, a Daniel Ibrahim and Darío Lupiáñez, both at the Max Planck Institute for Molecular Genetics, and École Normale Supérieure de Lyon's Uschi Symmon sought crowd-sourced funds to analyze the genome of the cat LilBub. LilBub, they noted, stayed the size of a kitten and has extra digits on each paw, no teeth, and osteopetrosis. By sequencing her genome, they hoped to uncover genetic variants associated with her traits.
The researchers and their team now report in a preprint at BioRxiv that they've uncovered two mutations in LilBub's genome. One is a heterozygous mutation in the Sonic hedgehog gene, which has previously been observed among Hemingway cats, which also exhibit polydactyly. The other mutation is a novel homozygous frameshift deletion affecting the TNFRSF11A gene, the human version of which has been implicated in osteopetrosis. The variant was also not present in the cats sequenced through the 99 Lives Consortium.
"However, there might be additional variants that contribute to certain aspects of the phenotype that we might have overlooked in the analysis," Symmons says in a statement. He adds that they welcome other researchers to take a look at LilBub's genome.