The fawn color in Doberman pinschers is the result of receiving each of two recessive genes from both parents. One set of genes results in a red coat, rather than the dominant black color. The other set dilutes red to fawn.
Because fawn is the result of homozygous recessive genes, breeding fawn parents always gives fawn puppies. The dilute gene is linked to color dilution alopecia, a genetic disorder that causes a dog's fur to fall out in patches. The skin becomes patchy and itchy, and secondary bacterial infections may develop as the dog scratches himself and damages his skin. There is no cure, and affected dogs need special care to keep their coats and skin clean and moist.