Hypotrichosis with thymic aplasia

Hypotrichosis is an inherited condition that affects coat development from birth due to genetic mutations that alter the production or structure of proteins necessary for hair growth. In the Burmese breed, a specific genetic variant has been identified in the FOXN1 gene, which is involved in epithelial cell development and immunity.

Symptoms

Hypotrichosis is characterized by the birth of hairless cats that develop a sparse, short and fragile coat over time. In addition, the skin is wrinkled and has a greasy appearance. These cats are often short-lived, as they frequently die or are euthanized before the age of eight months due to severe skin, digestive or respiratory problems.

Disease Management

There is no definitive treatment for this disease, but management focuses on improving the quality of life of the affected animal through preventive skin care to avoid infections, proper feeding and regular veterinary check-ups.

Genetic basis

This disease follows an autosomal recessive mode of inheritance. Autosomal recessive inheritance means that the cat, regardless of sex, must receive two copies of the mutation or pathogenic variant to be at risk of developing the disease. Both parents of an affected cat must carry at least one copy of the mutation. Animals with only one copy of the mutation are not at increased risk of developing the disease, but may pass the mutation on to future generations. Breeding between cats carrying genetic variants that may cause disease is not recommended, even if they do not show symptoms.

Technical report

Congenital hypotrichosis with short life expectancy is a hereditary condition characterized by the birth of hairless cats, affecting several breeds such as the Sphynx, Donskoy and Peterbald. This condition is associated with specific genetic mutations, with the KRT71 gene being responsible in the case of the Sphynx. In contrast, in the Burmese breed, hypotrichosis has been linked to mutations in the FOXN1 gene. This gene encodes a protein belonging to the FOX family of transcription factors, essential for the development of epithelial cells of the skin and thymus. A specific genetic variant found in affected Burmese cats is a c.1030_1033del deletion in FOXN1, considered a deleterious mutation resulting in a truncated protein unable to perform its normal functions, including the regulation of key genes for cell development and immunity.

Most affected breeds

Burmese

Bibliography

Abitbol M, Bossé P, Thomas A, et al. A deletion in FOXN1 is associated with a syndrome characterized by congenital hypotrichosis and short life expectancy in Birman cats. PLoS One. 2015 Mar 17