Dilute (D Locus/Blue)

Quick Summary

Several gene variants are known to produce dilute coloration in dogs. Colors are lightened (diluted) to paler shades as a result of the variants' effects on pigmentation.

American Staffordshire Terrier with blue coat
Black coloration diluted to blue in an American Staffordshire Terrier

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Phenotype: Base coat colors are lightened (diluted) to paler shades. For example, black becomes a gray-blue color (often called "blue" by breeders) and chocolate brown becomes a pale silvery red (in some breeds, this can be called "lilac"; in the French Bulldog, this is typically referred to as "isabella" - other breeds may have different names for this dilution).

Mode of Inheritance: Autosomal recessive

Alleles: D = Non-dilute, d1 = Dilute (variant 1, common), d2 = Dilute (variant 2), d3 = Dilute (variant 3, rare)

Breeds appropriate for testing: Many breeds

Explanation of Results:

  • Dogs with D/D genotype are not expected to display dilute coat colors; they have no known dilution variants. They cannot produce dilute offspring or transmit any of the known dilution variants to their offspring.
  • Dogs with D/d1, D/d2, or D/d3 genotype are not expected to display dilute coat colors, but they are carriers of dilution variants. They will transmit the dilution variant they carry to 50% of their offspring. Matings between two carriers of dilute variants are expected to produce 25% puppies with dilute coat colors.
  • Dogs with d1/d1, d2/d2, d3/d3, d1/d2, d1/d3, or d2/d3 genotype are expected to display dilute coat colors. They will transmit a dilution variant to all of their offspring.

Results of this test can be submitted to the OFA (Orthopedic Foundation for Animals)

Turnaround Time
At least 15 business days; may be delayed beyond 15 business days if sample requires additional testing, or a new sample is requested.
Price

$55 one test per animal
$75 two tests for coat color/fur type/bobtail (same animal) 
+ $15 each additional test if ordering more than three coat color/fur type/bobtail tests on the same animal

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Sample Collection

Dog DNA tests are carried out using cells brushed from your dog's cheeks and gums. The preferred cytology brushes are sent to you by mail, or you may provide your own brushes. For accepted alternative brushes, click here

We recommend waiting until puppies are at least three weeks old before testing.

 

Dog having its cheeks and gums brushed for DNA samples
Cheek and gum brushing technique for canine DNA sample collection

Step-By-Step:

  1. Make sure the dog has not had anything to eat or drink for at least 1 hour prior to collecting sample.
  2. When swabbing puppies, isolate each puppy from the mother, littermates and any shared toys for 1 hour prior to swabbing. Puppies should not have nursed or eaten for 1 hour prior to collecting sample.
  3. If collecting samples from more than one dog, make sure to sample one dog at a time and wash your hands before swabbing another dog.
  4. Label brush sleeve with name or ID of dog to be sampled.
  5. Open brush sleeve by arrow and remove one brush by its handle.
  6. Place bristle head between the dog’s gums and cheek and press lightly on the outside of the cheek while rubbing or rotating the brush back and forth for 15 seconds.
  7. Wave the brush in the air for 20 seconds to air dry.
  8. Insert brush back into sleeve.
  9. Repeat steps 5 - 8 for each unused brush in sleeve on a fresh area of cheek and gums. Make sure to use and return all brushes sent by the VGL. In most cases, it will be 3 brushes per dog. If using interdental gum brushes, please note that the VGL requires 4 brushes per dog and only moderate or wide interdental gum brushes are accepted.
  10. Do not seal brushes in sleeve.
  11. Place all samples in an envelope and return to the address provided.

ATTENTION:

  • Do not collect saliva/drool – the key to obtaining a good sample is getting cheek cells on the swab
  • Do not rub swab on the dog’s tongue or teeth – this will result in poor quality sample
  • Do not collect a sample from a puppy that has recently nursed – the mother’s genetic material can rub off on the puppy’s mouth and contaminate the sample
Additional Details

Weimaraner
Chocolate/liver diluted to Silver Gray in a Weimaraner, a breed fixed for dilute

A recessive mutation d1, previously named d, in the melanophilin (MLPH) gene (g.48121642G>A, c.-22G>A) was identified as the cause of color dilution phenotypes in several dog breeds (Drögemüller et al. 2007). However, this mutation alone does not account for all dilute color phenotypes. In 2018, Bauer et al. identified a second dilution in MLPH, variant d2 (c.705G>C, p.Gln235His) in the Sloughi, Chow Chow, and Thai Ridgeback dogs. Analysis at the Veterinary Genetics Laboratory (VGL) determined that the d2 variant is present at a frequency of less than 1% in phenotypically dilute French Bulldogs, thus suggesting that additional variants also cause this phenotype. Subsequent research at the VGL identified a third, very rare dilution variant d3 (c.667_668insC, p.His223Profs*41). The d3 variant has been detected in the Italian Greyhound, Chihuahua, Mudi, Pumi, Shih Tzu, Pekingese, Tibetan Mastiff, Yorkshire Terrier, Shetland Sheepdog, indigenous dogs, and wolf-dog hybrids (Van Buren et al. 2020).

Two copies of any of the three dilution variants, or any combination of two of these variants, are necessary to lighten the color. The d1 mutation is known to cause a reduction in the amount of full-length protein product, thus producing less pigment. The effect of the d2 mutation on the resultant protein is unknown, although in the homozygous state it dilutes color. The phenotype produced by two copies of the d3 variant is unknown, but this mutation is predicted to shorten the MLPH protein and likely disrupt function. Dogs that are compound heterozygotes d1/d2, d2/d3, or d1/d3 have a dilute phenotype. This diagnostic DNA test can detect all three known variants of the MLPH gene.

 

Note: The known variants d1, d2, and d3 do not account for all color dilution in some breeds such as Doberman Pinscher, French Bulldog, Italian Greyhound, and English Bulldog. This means that there are still unknown mutations that dilute color which need to be investigated. In these breeds, and likely others, some dogs may carry one known and one unknown dilution mutation and present a dilute phenotype.
Type of Sample
Cytology Brush - supplied by VGL at no additional charge (PREFERRED)
Mini mascara brushes - supplied by owner (click for accepted type)
Interdental/GUM brushes - supplied by owner (click for accepted types)

Species

Dog

Breed

AMB/AMBOR Affenpinscher Afghan Hound Africanis Aidi Ainu Dog Airedale Terrier Akbash Dog Akita: American type Akita: Blend, Other Akita: Japanese type Akita: Unregistered Alaskan Husky Alaskan Klee Kai Alaskan Malamute Alaskan Sled Dog Alpine Dachsbracke American Bandogge Mastiff American Blue Gascon Hound American Bulldog American Bully American Eskimo, Miniature American Eskimo, Standard American Eskimo, Toy American Foxhound American Hairless Terrier American Pit Bull Terrier American Staffordshire Terrier American Water Spaniel Anatolian Shepherd Dog Anglo-Francais de Moyen Venerie Anglo-Francais de Petite Venerie Appenzeller Ariegeois Armant Aryan Molossus Aussiedoodle Australian Cattle Dog Australian Cobberdog Australian Domestic Dog Australian Kelpie Australian Labradoodle Australian Shepherd Australian Shepherd, Miniature Australian Terrier Austrian Black & Tan Hound Austrian Pinscher Austrian Shorthaired Pinscher Austrian Smoothhaired Hound Azawakh Bali Street Dog Barbet Basenji Basque Sheepdog Basset Artesian Normand Basset Bleu de Gascogne Basset Fauve de Bretagne Basset Hound Bavarian Mountain Hound Beagle Beagle Harrier Bearded Collie Beauceron Bedlington Terrier Belgian Griffon Belgian Laekenois Belgian Malinois Belgian Mastiff Belgian Sheepdog Belgian Tervuren Bergamasco Berger Picard Berger de Pyrenees, Smooth Muzzled Berger du Languedoc Berner Laufhund Berner Neiderlaufhund Bernese Mountain Dog Bichon Frise Biewer Biewer Terrier Biewer Yorkshire Terrier Biewer, Biro Billy Black & Tan Coonhound Black Forest Hound Black Mouth Cur Black Russian Terrier Bloodhound Blue Lacy Bluetick Coonhound Bolognese Border Collie Border Collie Cross Border Terrier Borzoi Bosnian Roughhaired Hound Boston Terrier Bouvier Des Ardennes Bouvier Des Flandres Boxer Boykin Spaniel Bracco Italiano Braque Dupuy Braque Francais, de Grande Taille Braque Francais, de Petite Taille Braque Saint-Germain Braque d'Auvergne Braque de l'Ariège Braque du Bourbonnais Brazilian Terrier Briard Briquet Griffon Vendeen Brittany Broholmer Bruno Jura Laufhund Brussels Griffon Bull Terrier Bulldog Bullmastiff CB Romanesc Carpatin Ca De Bestier Cairn Terrier Canaan Dog Canadian Cur Canadian Eskimo Dog Cane Corso Canis lupus Cardigan Welsh Corgi Carolina Dog Catahoula Leopard Dog Catalan Sheepdog Caucasian Ovcharka Cavalier King Charles Spaniel Central Asian Shepherd Cesky Fousek Cesky Terrier Chart Polski Chesapeake Bay Retriever Chien Francais Blanc et Noir Chien Francais Blanc et Orange Chien Francais Blanc et Tricolore Chien d'Artois Chihuahua Chinese Crested Chinese Foo Dog Chinook Chortaj Chow Chow Cimarron Uruguayo Cirneco dell'Etna Clumber Spaniel Cockapoo Cocker Spaniel, American Cocker Spaniel, Unknown Variety Collie Cook Island Feral Dog Coton de Tulear Coyote Croatian Sheepdog Crossbred Curly-Coated Retriever Czech Wolfdog Czechoslovakian Vlcak Dachshund Dalmatian Dandie Dinmont Terrier Danish Broholmer Danish/Swedish Farmdog Denmark Feist Deutsch Kooiker Deutsch-Drahthaar Deutsche Bracke Deutscher Wachtelhund Dingo Doberman Pinscher Dogo Argentino Dogue de Bordeaux Drentse Patrijshond Drever Dunker Dutch Malinois Dutch Shepherd, Longhaired Dutch Shepherd, Roughhaired Dutch Shepherd, Shorthaired Dutch Smoushond East European Shepherd East Siberian Laika English Bulldog English Cocker Spaniel English Coonhound English Foxhound English Mastiff English Setter English Shepherd English Springer Spaniel English Toy Spaniel English Toy Terrier Entlebucher Epagneul Bleu de Picardie Epagneul Breton Epagneul Francais Epagneul Picard Epagneul Pont-Audemer Estonian Hound Estrela Mountain Dog Eurasian Farm Collie Fell Hound Fell Sheepdog Field Spaniel Fila Brasileiro Finnish Hound Finnish Lapphund Finnish Spitz Flat-Coated Retriever Fox Fox Terrier, Smooth Fox Terrier, Wire French Bulldog Galgo Espanol German Drahthaar German Hunt Terrier German Longhaired Pointer German Pinscher German Sheeppoodle German Shepherd German Shorthaired Pointer German Wirehaired Pointer German Wolfspitz Giant German Spitz Giant Schnauzer Glen of Imaal Terrier Golden Retriever Goldendoodle Gordon Setter Gr Ang-Fr Tricolor Hound Gr Ang-Fr W & B Hound Gr Ang-Fr W & O Hound Grand Anglo-Francais Grand Basset Griffon Vendeen Grand Bleu de Gascogne Grand Gascon-Saintongeois Grand Griffon Vendeen Great Dane Great Pyrenees Greater Swiss Mountain Dog Greek Harehound Greek Sheepdog Greenland Dog Greyhound Griffon Bleu De Gascogne Griffon Fauve de Bretagne Griffon Nivernais Haldenstovare Hamiltonstovare Hanoverian Hound Harlequin Pinscher Harrier Havana Silk Havanese Hawaiian Poi Dog Heading Dog Hertha Pointer Hovawart Huntaway Hygenhund Ibizan Hound Iceland Dog Inca Hairless Dog Inuit Sled Dog Inuit Sled Dog Mix Irish Red & White Setter Irish Setter Irish Terrier Irish Water Spaniel Irish Wolfhound Islandsk Farehund Istrian Hound, Smoothhaired Istrian Hound, Wirehaired Italian Greyhound Italian Hound Jack Russell Terrier Japanese Chin Japanese Spitz Japanese Terrier Jindo Dog Jura Neiderlaufhund Kai Dog Kangal Dog Kangaroo Dog Karakachan Karelian Bear Dog Karelo-Finnish Laika Kayo Inu Keeshond Kerry Beagle Kerry Blue Terrier King Shepherd Kintamani Dogs Kishu Komondor Kooikerhondje Koolie Korean German Shepherd Kraski Ovcar Kromfohrlander Kuvasz Kyi Leo Labradoodle Labrador Retriever LabxGolden Laekense Lagotto Romagnolo Lakeland Terrier Lamalese Lancashire Heeler Landseer Lapinporokoira Lapponian Herder Large Munsterlander Large Spanish Hound Latvian Hound Leonberger Leopard Cur Leopard Hound Levesque Lhasa Apso Lithuanian Hound Llewellin Setter Lowchen Lundehund Lurcher Luzerner Laufhund Luzerner Neiderlaufhund Magyar Agar Majestic Tree Hound Maltese Manchester Terrier Manchester Terrier, Toy Maremma Sheepdog Mastiff Matthes Lion Hound McNab Mi-Ki Middle Asian Owtcharka Miniature American Shepherd Miniature Bull Terrier Miniature Goldendoodle Miniature Pinscher Montenegrin Mountain Hound Moscow Longhaired Toy Terrier Moscow Watchdog Mountain Cur Mudi Mullins Feist Native American Indian Dog Neapolitan Mastiff New Guinea Singing Dog Newfoundland Norfolk Terrier Norrbottenspets North American Shepherd Northeasterly Hauling Laika Norwegian Buhund Norwegian Elkhound Norwegian Elkhound, Black Norwegian Lundehund Norwich Terrier Nova Scotia Duck Tolling Retriever Old Danish Bird Dog Old English Sheepdog Olde English Bulldogge Otterhound Owczarek Podhalanski Papillon Parson Russell Terrier Patterdale Terrier Pekingese Pembroke Welsh Corgi Perdiguero Navarro Perdiguero Portugueso Perdiguero de Burgos Perro de Pastor Mallorquin Perro de Presa Canario Perro de Presa Mallorquin Peruvian Hairless Dog Peruvian Inca Orchid Petit Basset Griffon Vendeen Petit Bleu de Gascogne Petit Brabancon Petit Gascon-Saintongeois Petit Griffon Bleu de Gascogne Phalene Pharaoh Hound Pit Bull Plott Hound Podenco Canario Podengo Portugueso Grande Podengo Portugueso Medio Podengo Portugueso Pequeno, Smooth Podengo Portugueso Pequeno, Wirehaired Pointer Poitevin Polish Hound Polish Lowland Sheepdog Polish Owczarek Podhalanski Polski Owczarek Nizinny Pomeranian Pomsky Poodle, Miniature Poodle, Standard Poodle, Toy Poongsan Dog Porcelaine Portuguese Cattle Dog Portuguese Pointer Portuguese Sheepdog Portuguese Water Dog Posavac Hound Prager Ratter Pudelpointer Pug Puli Pumi Pyrenean Mastiff Pyrenean Shepherd Rafeiro do Alentejo Rat Terrier Red & White Setter Redbone Hound Rhodesian Ridgeback Ridgeback Cross Rottweiler Rumanian Sheepdog Russell Terrier Russian Harlequin Hound Russian Hound Russian Samoyed Laika Russian Spaniel Russkiy Toy Russo-European Laika Saarlooswolfhond Sabuesos Espanol Lebrero Sabuesos Espanol de Monte Saint Bernard Saint Hubert Jura Laufhund Saint Usage Spaniel Saluki Samoyed Sanshu Dog Santal Hound Sapsaree Sarplaninac Schapendoes Schillerstovare Schipperke Schnauzer, Miniature Schnauzer, Standard Schweizer Laufhund Schweizer Neiderlaufhund Scottish Collie Scottish Deerhound Scottish Terrier Sealyham Terrier Segugio Italiano a Pelo Forte Segugio Italiano a Pelo Raso Seppala Siberian Sleddog Serbian Hound Serbian Tricolor Hound Shar Pei Shetland Sheepdog Shiba Inu Shih Tzu Shikoku Shiloh Shepherd Dog Shiloh Shepherd, ISSA Siberian Husky Silken Windhound Silky Terrier Skye Terrier Sloughi Slovak Cuvac Slovakian WH Pointing Dog Smalandsstovare Small German Spitz Small Munsterlander Soft Coated Wheaten Terrier South African Boerboel Mastiff South Russian Ovcharka South Russian Steppe Hound Spanish Alano Spanish Mastiff Spanish Water Dog Spinone Italiano Sporting Lucas Terrier Springer Spaniel Sri Lankan Dog Stabyhoun Staffordshire Bull Terrier Standard German Spitz Stephens Stock Stichelhaar Strellufstover Stumpy-Tail Cattle Dog Styrian Roughhaired Mountain Hound Sudanese Dog Sussex Spaniel Swedish Elkhound Swedish Lapphund Swedish Vallhund Tahltan Bear Dog Taigan Tamaskan Tasy Teddy Roosevelt Terrier Telomian Tengger Dog Tenterfield Terrier Thai Ridgeback Thornburg Feist Tibetan Mastiff Tibetan Spaniel Tibetan Terrier Tosa Inu Tosa Ken Toy Fox Terrier Toy German Spitz Transylvanian Hound, Long Transylvanian Hound, Short Treeing Feist Treeing Tennessee Brindle Treeing Walker Coonhound Turkish Feral Dog Turkish Greyhound Tyrolean Hound Tyroler Bracke Unknown Vasgotaspets Vizsla Volpino Italiano Walker Coonhound Weimaraner Welsh Hound Welsh Sheepdog Welsh Springer Spaniel Welsh Terrier West Highland White Terrier West Siberian Laika Westphalian Dachsbracke Wetterhoun Whippet Whippet, Longhaired Cross White Shepherd Windsprite (Longhaired Whippet) Wirehaired Pointing Griffon Wirehaired Vizsla Wolf Wolf Hybrid Working Dog X-Bred Coonhound Xoloitzcuintli Xoloitzcuintli, Toy Yorkshire Terrier
+ View All Breeds
Type of Test
Coat Color and/or Type
Results Reported As
Test Result Dilute

D/D

No known dilution variants present.

D/d1

Carries 1 copy of the dilution variant.

D/d2

Carries 1 copy of the dilution variant.

D/d3

Carries 1 copy of the dilution variant.

d1/d1

Dilute, 2 copies of the dilution variants.

d2/d2

Dilute, 2 copies of the dilution variants

d3/d3

Dilute, 2 copies of the dilution variants.

d1/d2

Dilute, 2 copies of the dilution variants.

d1/d3

Dilute, 2 copies of the dilution variants.

d2/d3

Dilute, 2 copies of the dilution variants.
References

Drögemüller, C., Philipp, U., Haase, B., Günzel-Apel, A-R., & Leeb, T. (2007). A noncoding melanophilin gene (MLPH) SNP at the splice donor of exon 1 represents a candidate causal mutation for coat color dilution in dogs. Journal of Heredity, 98(5), 468-473. doi: 10.1093/jhered/esm021

Bauer, A., Kehl, A., Jagannathan, V., & Leeb, T. (2018). A novel MLPH variant in dogs with coat colour dilution. Animal Genetics, 49(1), 94-97. doi: 10.1111/age.12632

Van Buren, S. L., Minor, K. M., Grahn, R. A., Mickelson, J. R., Grahn, J. C., Malvick, J., Colangelo, J.R., Mueller, E., Kuehnlein, P., & Kehl, A. (2020). A Third MLPH Variant Causing Coat Color Dilution in Dogs. Genes, 11(6), 639. doi: 10.3390/genes11060639

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