A mutation in the KIT-gene is associated with a white spotting pattern in German Shepherd Dogs, this pattern is  also called Panda White Spotting. The mutation is very recent, it appeared spontaneously in a female born in 2000. The gene for white-spotting is known as the S-locus (MITF-Gene), however this mutation in the German Shepherd dogs is in a different gene then the mutation causing white spotting in other dog breeds. The mutation causes white markings on the face, limbs, belly, neck, and tip of the tail, with the white being concentrated toward the front of the dog, similar to the irish spotting pattern. The amount of white can vary from dog to dog. The mutation that causes the Panda White pattern in German Shepherd dogs is in homozygous state (two copies of the mutation) considered embryonic lethal as no live dogs with the pattern and with two copies of the mutation have been observed. This means that pups that are homozygous for the Panda mutation do not develop in the uterus and are reabsorbed very early in the development process. Dogs that are heterozygous (one copy of the mutation) do not have any health defects associated with the Panda pattern. The Coat Colour Panda White Spotting test (H354) tests for the genetic status of the KIT-gene. This gene has two variants (alleles), P and N. The allele P is dominant. One copy of the P allele results in dogs with the Panda white pattern. Two copies of the P allele result in early embryonic death. The allele N does have no effect on the coat colour.

The Coat Colour Panda White Spotting test encloses the following results.

The Agouti gene (ASIP gene) is responsible for the production of a protein that regulates the distribution of black pigment (eumelanin) within the hair shaft. This gene is also known as the A-locus and determines whether an animal expresses an agouti appearance, and if so what type, by controlling the distribution of pigment in individual hairs. The agouti pattern can be seen in both black-based and red-based colours. The coat colour is further complicated by the interaction with the K-locus and the E-locus. The agouti pattern is only expressed if on the K-locus no copy of the KB allele is present in combination with at least one copy of the E or Em allele on the E-locus. The Coat Colour A-Locus test (H820) tests for the genetic status of the A-locus. The A-locus has four variants (alleles). The most dominant allele is Ay, followed by aw, then at, then a. The dominant Ay allele produces a sable or fawn coat colour. The allele aw produces a colour known as wild sable or wild type. With this colouration, the hairs switch pigmentation from black to reddish or fawn. This colour is sometimes seen in German Shepherds and other shepherd breeds. The allele at results in tan points (tan markings on a dark dog) and produces black-and-tan and tricolour dogs. A tricolour dog is black-and-tan plus white. The allele a is also called the recessive black allele and results in a solid black/brown/blue/lilac or bicolour dog. Some breeds are fixed for only one variant. The Norwegian Elkhound is fixed for the aw allele and the Beagle is fixed for the at allele. In many breeds 2 or 3 alleles are present.

The Coat Colour A-Locus test encloses the following results.

The Silver gene (SILV gene), also called premelanosome protein (PMEL17 gene) is responsible for Merle. This gene is also known as M-Locus. Merle only dilutes eumelanin (black) pigment; dogs with two copies of the allele e (homozygous e/e) at E-Locus have no black pigment, thus do not express merle. Merle is an incompletely dominant coat color pattern characterized by irregularly shaped patches of diluted pigment and solid color. Blue and partially blue eyes are typically seen with merle, and merle dogs often have a wide range of auditory and ophthalmologic defects. Breeds with merle coat pattern are Shetland Sheepdog, Collie, Border Collie, Australian Shepherd, Cardigan Welsh Corgi, Catahoula Leopard Dog, Dachshund, Great Dane, Bergamasco Sheepdog and Pyrenean Shepherd. The Coat Colour Merle test (H630) tests for the genetic status of the M-locus. The M-locus has three variants (alleles): M (merle, SINE with longer poly-A tail), Mc (cryptic merle, SINE with shorter poly-A tail) and N (non-merle, no SINE insertion. Dogs with cryptic merle (also called phantom or ghost merle), typically display little to no merling and some may be misclassified as non-merles.

The Coat Colour Merle test encloses the following results.

The Hermansky-Pudlak syndrome 3 (HPS3) gene, also known as cocoa coat colour or co-locus is responsible for the brown colour in French Bulldogs. Mutations of the HPS3 gene interfere with the eumalin (black pigment) synthesis, which results in brown-pigmentation. The brown colour caused by the HPS3-variants is known to darken over age and to be slightly darker in adults that the brown colour caused by the TYRP1-related variants (B-locus). The co-locus is recessive and therefore needs two copies of the gene to present the phenotype. This co-locus can be present in French Bulldogs with various coat colours; brown, lilac, black, blue, cream, fawn or white, but the phenotype might be less visible in some cases. The complete phenotype of the coat, footpads and nose also depends on the A-, E-, K- and B-locus genes. Right now, no interaction in French Bulldogs between the co- and B-locus have been reported. Therefore it is not possible to predict what phenotype the combination of these variants would cause.

N/N = cocoa variant not present. The cocoa phenotype is not expressed, the offspring won’t inherit a copy of the co-locus.

N/co = carrier of the cocoa variant. Phenotype is not present. 50% of the offspring will inherit one copy of the co-locus.

co/co = the cocoa phenotype is present. The display of this phenotype depends on the interaction between other colour genes (loci). 100% of the offspring will get one copy of the co-locus. 

The white spotting patterns that occur in many dog breeds do not have a uniform genetic basis. The Microphthalmia Associated Transcription Factor gene (MITF gene) is associated with many white spotting patterns. This gene is also known as the S-Locus. There are three major white spotting patterns described. One pattern is called “Irish spotting” and is a symmetrical pattern with white markings on the undersides, collar and muzzle, and/or blaze as demonstrated by breeds such as the Boston Terrier, Corgi, Bernese Mountain dog and Basenji. Another pattern of less symmetrical white spotting in which random white spots occur on the body of the dog is often called piebald, parti or random white and is observed in several breeds, including the Beagle and Fox Terrier. The third major pattern is called extreme white and results in a dog that is almost entirely white but usually has at least some color on the head. Furthermore, there is a pattern called mantle, this pattern is similar to Irish spotting but with more white extending onto the thigh and up the torso, as seen in some Great Danes. Another pattern that is similar to Irish spotting is called flash or pseudo-Irish and occurs in Boxers. A mutation found in the MITF gene is associated with the piebald spotting pattern in more than 25 different dog breeds. The Coat Colour Piebald test (H326) tests for the genetic status of this mutation. It results in two variants (alleles). The allele N does not produce a piebald pattern, therefor dogs with two copies of the N allele do not display the piebald pattern. The allele S is associated with the piebald pattern, however the amount of white spotting expressed varies from breed to breed and among individuals within a breed. In many breeds such as Collie, Great Dane, Italian Greyhound, Shetland Sheepdog, Boxer and Bull Terrier, piebald behaves as a dosage-dependent trait. In those breeds the allele S is semi-dominant. One copy of the S allele (S/N) results in a limited white spotting pattern. Dogs with two copies of the  S allele (S/S) display more extreme white with colour only on the head and perhaps a body spot. In Boxers and Bull Terriers, dogs that have two copies of the S allele (S/S) are completely white while dogs that only have one copy of the S allele (N/S) display the mantle pattern (called flash in these breeds). However, additional mutations in MITF or other white-spotting genes that affect the amount of white being expressed appear to be present in these breeds. In some other breeds, the allele S is recessive and in those breeds two copies are needed to produce the piebald pattern.

The Coat Colour Piebald test encloses the following results: