International Campaign for genetic research on early-onset aggressive melanoma in grey Connemara ponies

Melanoma is a prominent issue in grey Connemara ponies, and its management can become especially challenging when it develops in young horses.

Goal: By studying the link between early-onset aggressive forms of the disease, which is defined in our study as melanoma onset in ponies under 6 years of age, and the mutation causing grey, our research aims at developing reliable and accurate genetic testing tools that could help preserve the grey coat color within the Connemara breed, while lowering their predisposition to melanoma.

Advancements in genetic technologies have recently established that not one, but two mutations on the same gene (syntaxin-17, or STX17) can lead to their hair greying. Three versions of this gene therefore coexist:

- “G1”, which is the unmutated version of the gene = non grey coat color

- “G2” two copies of the gene = grey

 -“G3”, three copies of the gene = grey

Each horse has alleles (one inherited from the dam and one from the sire), which means that a horse can possess any of the combinations made from G1, G2 and G3.

- G1/G1 = all non-grey horses (N/N genotype on test result)

- G1/G2, G2/G2, G2/G3 or G3/G3 combinations can be found in grey horses (N/G or G/G genotype on test results)

Melanoma Association: Preliminary research indicates that the G3/G3 combination is associated with a higher risk of developing such early-onset forms of the disease, while the risk is lowered in horses with G1/G2.

Further research is needed however to understand the impact of the other combinations on early-onset aggressive melanoma risk. With this, the Finno Laboratory at the UC Davis School of Veterinary Medicine would greatly appreciate your contribution to our research by providing additional samples.

Should you own a grey Connemara pony that developed melanoma before the age of six or is melanoma free and over the age of 15, we would be interested in collecting a hair sample for analysis at the UC Davis Veterinary Genetics Laboratory. If interested in supporting our study, please reach out to Anushka Panjwani ([email protected]) for US-based samples, and Oceane Soussiel ([email protected]) for international samples.

Thank you very much for your time and consideration!