In 1976, a "white" Doberman Pinscher was whelped and was subsequently bred to her son, who was also bred to his litter sisters. This tight inbreeding continued for some time to allow the breeders to "fix" the mutation. White Dobermanns are a cream color with white markings and blue eyes. Although this is consistent with albinism, the proper characterization of the mutation is currently unknown. The animals are commonly known as tyrosinase-positive albinoids, lacking melanin in oculocutaneous structures. This condition is caused by a partial deletion in the SLC45A2 gene.