White Paws (KIT gene, Burmese)

This trait refers to the lack of pigmentation in the paws of cats, resulting in white paws that give them the appearance of wearing gloves or socks.

Definition

This trait is associated with a variant in the KIT gene, which plays a crucial role in the migration and proliferation of melanocytes (pigment cells) during embryonic development. The variant in the KIT gene inhibits the migration of melanocytes to the limbs, resulting in a lack of pigment in the legs.

Genetic basis

The variant responsible for this characteristic phenotype consists of a deletion and insertion that causes loss of function of the KIT gene. This variant is inherited in an autosomal recessive manner, which means that two copies of the variant are required for the trait to manifest. However, the presence of a single copy of the variant can be transmitted to offspring with a 50% probability.

Other relevant information

In Birman cats, the "glove" pattern is a breed standard, and variability in the expression of the KIT gene can affect the extent and symmetry of the white paws.

Bibliography

Lyons LA. Feline genetics: clinical applications and genetic testing. Top Companion Anim Med. 2010;25(4):203-212.

Montague MJ, Li G, Gandolfi B, et al. Comparative analysis of the domestic cat genome reveals genetic signatures underlying feline biology and domestication. Proc Natl Acad Sci U S A. 2014;111(48):17230-17235.