Grey depigmentation

DNA test The DNA test verifies the presence of the grey mutation. Grey is the dominant gene responsible for the gradual and...

€49.20

Sample Requirements

5 mL - blood - K3 EDTA tube

Send your sample by regular mail or express delivery to:

Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal

Turnaround Time

2 to 5 working days

About the test

The Grey Coat Colour DNA Test detects the dominant Grey (G) mutation, responsible for the gradual loss of coat pigmentation throughout a horse's life.

Grey is a dominant colour modifier that causes horses of any base coat colour to progressively fade, often becoming almost completely white with age. This test identifies whether a horse carries one or two copies of the Grey gene.

Why test?

Testing for the Grey gene helps to:

Confirm whether a horse carries the Grey mutation.
Identify grey foals before depigmentation becomes visible.
Differentiate true grey horses from naturally light-coloured horses.
Support breeding programs aiming to produce or avoid grey offspring.
Determine whether a grey horse is heterozygous or homozygous for the Grey gene.

Results

The DNA test verifies the presence of the grey mutation and presents results as one of the following:

N/ – Non-grey horse. Negative for grey. Horse will not turn grey.
G/N - Grey horse. Positive for dominant grey gene, carrying a single inherited copy. Carrier’s coat modified and will eventually become de-pigmented. Heterozygous grey horses are statistically likely to pass the gene to 50% off their progeny when bred.
G/ - Grey horse. Positive for dominant grey gene, carrying two inherited copies. Carrier’s coat modified and will eventually become de-pigmented. Homozygous grey horses are genetically bound to pass the gene to 100% of their progeny when bred, so all foals will receive grey and fade-out.

Additional information

Grey is the dominant gene responsible for the gradual and progressive de-pigmentation (fading) of the carrying horse. Grey cannot be considered a base-color, or a dilution, but rather a gene which slowly removes pigment from the coat.

This gene is considered to be the ‘strongest’ of all coat modifiers, and acts upon any base-color regardless of the carrying horse’s phenotype. The fading process itself may last for years, but once hair is de-pigmented, the horse’s original colouring will never return.

Since grey is a dominant gene, where it is present it is expressed. However, the final phenotype of the carrier will vary from horse to horse.

Some grey horses fade to full de-pigmentation (almost pure white) whereas others may be ‘fleabitten’. Fleabitten refers to grey horses with tiny non-faded spots or ‘fleabites.’

Equine melanomas occur most often in grey horses, and it is expected that at least 80% of grey horses will develop melanoma.

FAQs

What does this test detect?

The test detects the dominant Grey (G) mutation responsible for progressive coat depigmentation.

Can a foal test positive before becoming grey?

Yes. Foals carrying the Grey gene are born with their base coat colour and may not begin to grey until several months or even years later.

What is the difference between G/N and G/G?

A G/N horse carries one copy of the Grey gene and has a 50% chance of passing it to each foal. A G/G horse carries two copies and will pass the Grey gene to all offspring.

Does the Grey gene determine the horse's original coat colour?

No. The Grey gene only causes progressive fading. The underlying base coat colour is determined by other genes such as Extension, Agouti, Cream, and Dun.

Why is Grey testing useful for breeders?

DNA testing allows breeders to predict whether foals will eventually become grey and to make informed breeding decisions when selecting for or against the Grey trait.