Hereditary alopecia is rare in cats. Mexican hairless cats, a breed created by the Aztecs, were described in 1924 as follows: skin slightly wrinkled, bluish on the back, and lighter on the belly.Well-developed whiskers and light winter coat on the back and tip of the tail. In 1930, Létard studied a pair of hairless cats, describing them as having fleshy, very wrinkled, piebald slate skin. A hairless cat brought back from India was observed in 1930. In 1935, Letard studied two male hairless kittens from a litter of Siamese. He demonstrated the recessive autosomal nature of genetic transmission (hr) in this case. In 1966 in Canada, crosses in a litter of hairless cats produced only hairless cats that gave rise to the Sphynx (Canadian Hairless) breed.