This is a genetic disorder with incomplete penetrance leading to highly variable congenital eye malformations seen in young puppies.

  464 unrelated Golden Retrivers were screened (genotyped) of which 3 cases were heterozygous and diagnosed as showing the phenotype.

  These include unilateral or bilateral retina dysplasia and/or optic nerve hypoplasia.

  The disease is associated with abnormal SIX6 protein, which is a homeobox transcription factor with a known role in eye development.

In humans and other species, SIX6 loss of function variants were reported to cause congenital eye malformations.

This strongly suggests that the c.

487C>T variant detected contributed to the observed eye malformations.