Cleft lip with or without cleft palate in Nova Scotia Duck Tolling retriever

Cleft lip is a genetic disorder that occurs during the embryonic development of a puppy. Cleft lip may or may not extend to cleft palate. Clinical signs occur with cleft palate and include nasal discharge of fluid, sneezing, snorting, coughing, impaired ability to accept food and associated slowed growth and poor weight gain. Due to possible inhalation of food, pneumonia may develop.

Cleft in Nova Scotia Duck Tolling Retrievers can be caused by two different mutations - in the DLX6 gene or ADAMTS20. Genomia offers a test to detect the c.1358_1359del mutation in the ADAMTS20 gene.

The mode of inheritance of the mutation is autosomal recessive. This means that only individuals who inherit the mutated gene from both parents will develop the disease. Carriers of the mutated gene are clinically healthy but pass the mutation on to their offspring. In the case of a mating between two heterozygous individuals, theoretically 25% of the offspring will be completely healthy, 50% of the offspring will be carriers and 25% of the offspring will inherit the mutated gene from both parents and will therefore be affected by the disease.

The genetic test can clearly reveal the genotype of the animal and is a useful tool for breeders to prevent unintentional breeding of affected puppies.

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Reference:

Wolf, Z.T., Brand, H.A., Shaffer, J.R., Leslie, E.J., Arzi, B., Willet, C.E., Cox, T.C., McHenry, T., Narayan, N., Feingold, E., Wang, X., Sliskovic, S., Karmi, N., Safra, N., Sanchez, C., Deleyiannis, F.W., Murray, J.C., Wade, C.M., Marazita, M.L., Bannasch, D.L. : Genome-wide association studies in dogs and humans identify ADAMTS20 as a risk variant for cleft lip and palate. PLoS Genet 11:e1005059, 2015. Pubmed reference: 25798845