E Locus (Yellow / Red Extension)
Other names: E Locus (Extension: Yellow / Red / “Lemon”)
 Affected gene: MC1R
 Inheritance: Autosomal recessive
Mutation:
 
 
Red/yellow coat (e¹): CanFam3.1 chr5 g.63,694,334 G>A
 
 
c.916C>T p.(R306*)

OMIA reference: 001590-9615
B Locus
Affected gene: TYRP1
 Inheritance: Autosomal
Mutations:
 
 
bc = T>A, Chr11:33317810
 
 
bd = 3 bp deletion (del CCT), Chr11:33326727–33326729
 
 
bh = G>A, Chr11:33317814 (Husky)
 
 
bs = C>T, Chr11:33326685

Description:
Dogs carrying two copies of the b allele produce brown pigment instead of black pigment in their coat and skin. Dogs carrying only one copy of the b allele produce black pigment but can pass the b allele on to their offspring.
Dogs that are ee at the E locus and carry two b alleles have a red or cream coat, but their nose, eye rims, and paw pads are brown (sometimes referred to as a Dudley nose in Labrador Retrievers).
The terms liver or chocolate are commonly used to describe brown pigmentation in most breeds; in the Doberman Pinscher, this color is referred to as red.
D Locus (Dilution)
Affected gene: MLPH
 Inheritance: Autosomal recessive
Mutation:
 
 
Allele d¹: CanFam3.1 (chr25) g.48121642G>A, c.-22G>A

OMIA reference: 000031-9615
Characteristics:
Coat color dilution in several dog breeds is characterized by a specific pigmentation phenotype and may sometimes be associated with hair loss and recurrent skin inflammation, known as color dilution alopecia or black hair follicular dysplasia.