Unraveling the Genetic Basis of Congenital Sensorineural Deafness in Blue-Eyed White Alpacas

Principal investigator:

Felipe Fegundes de Avila
Veterinary Genetics Laboratory
University of California, Davis

Alpacas are economically important for their fleece, which offers a finer, softer, hypoallergenic, and eco-friendly textile. Alpaca fiber comes in different natural colors, but white fiber is desirable because it can be easily dyed to produce any color. Therefore, phenotypic selection is being used more frequently to increase the number of white individuals in U.S. herds. White alpacas are sometimes born with blue eyes, and approximately 70% of these individuals are deaf. Since alpacas are herd animals, adaption to deafness is possible; nonetheless, many breeders regard this as an undesirable trait, and the Canadian Llama and Alpaca Association considers deafness a congenital disqualifier, prohibiting deaf individuals from being registered. The genetic basis of coat color in alpacas is poorly understood, and contrary to other species (such as dogs, cats, horses, and humans), the genetic underpinnings of deafness in blue-eyed white alpacas remain largely unknown. We have examined the genomes of deaf blue-eyed white alpacas by high-throughput sequencing, with the goal to discover the causative mutation(s) for this trait. Our results have identified two mutations that likely interact to cause deafness in blue-eyed white alpacas. Our ultimate goal is to develop genetic tests that will allow owners to make informed breeding decisions when selecting for white coat color and minimizing the production of deaf animals.