Large scale across-breed genome-wide association study reveals a variant in HMGA2 associated with inguinal cryptorchidism risk in dogs

Cryptorchidism is the most common congenital sex development disorder in
dogs. Despite this, little progress has been made in understanding its
genetic background. Extensive genetic testing of dogs through consumer and
veterinary channels using a high-density SNP genotyping microarray coupled
with links to clinical records presents the opportunity for a large-scale
genome-wide association study to elucidate the molecular risk factors
associated with cryptorchidism in dogs. Using an inter-breed genome-wide
association study approach, a significant statistical association on
canine chromosome 10 was identified, with the top SNP pinpointing a
variant of HMGA2 previously associated with adult weight variance. In
further analysis we show that incidence of cryptorchidism is skewed
towards smaller dogs in concordance with the identified variant’s previous
association with adult weight. This study represents the first putative
variant to be associated with cryptorchidism in dogs.