UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory
Harlequin Pattern In Great Danes

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The interaction of many genes is involved in the variety of colors and patterns of dog coat color. Harlequin is a pattern seen in Great Danes resulting from the complex interaction of the Merle (PMEL17) and Harlequin (PSMB7) genes on black pigment. The dominant Merle gene, by itself produces dark spots on a dilute background on eumelanistic dogs. If a merle dog also inherits 1 copy of the Harlequin gene, the dark spots increase in size and the background pigment is removed altogether. Dogs that are not merle, or only have red pigment, cannot express the Harlequin gene. Two copies of Harlequin have not been observed and is presumed to be embryonic lethal, thus all Harlequin patterned dogs have only 1 copy of the mutation.

Results from the HARLEQUIN test are reported as:

N/N    No copies of Harlequin mutation are present.

N/H    1 copy of the Harlequin mutation is present. If the dog has merle and is black pigmented, the Harlequin pattern is expressed. Breedings between N/H dogs are expected to result in 25% embryonic lethal offspring.


Clark LA, KL Tsai, AN Starr, KL Nowend and KE Murphy. 2011. A missense mutation in the 20S proteasome β2 subunit of Great Danes having harlequin coat patterning. Genomics 97(4):244-248.

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