Cleft Palate

Cleft palate a craniofacial anomaly in puppies that causes clefts in the roof (palate) of the mouth and abnormal communication between the oral and nasal cavities.

Symptoms

Affected puppies have a cleft or fissure in the hard and soft palate from birth, which causes feeding difficulties and prevents them from growing at the same rate as their littermates. In addition, during feeding, milk can pass into the respiratory tract, increasing the risk of infections, which in some cases can compromise their survival.

Disease Management

In case your dog shows any symptoms, you should visit your veterinarian for evaluation. Both congenital and acquired cleft palate can be corrected by surgery, in the case of congenital cleft palate is indicated at an early age, preferably between 4-6 months, although in severe cases it may be earlier and puppies may need special care.

Genetic basis

This disease follows an autosomal recessive mode of inheritance. Autosomal recessive inheritance means that the dog, regardless of sex, must receive two copies of the mutation or pathogenic variant to be at risk of developing the disease. Both parents of an affected dog must carry at least one copy of the mutation. Animals with only one copy of the mutation are not at increased risk of developing the disease, but may pass the mutation on to future generations. Breeding between dogs carrying genetic variants that can cause disease, even if they do not show symptoms, is not recommended.

Technical report

The DLX6 gene produces a transcription factor that is expressed during development and is involved, together with DLX5, in the formation of craniofacial structures, the inner ear, limbs and brain. This gene is important in the differentiation of chondrocytes (cartilage cells) and osteoblasts (cells that produce the extracellular matrix of bones). In the study by Wolf et al. it was observed that this defect could be caused by a 2056 bp (base pair) insertion in a highly conserved region of the DLX6 gene that causes a premature stop codon to be produced.

Most affected breeds

Nova Scotia Duck Tolling retriever

Bibliography

Fiani N, Verstraete FJ, Arzi B. Reconstruction of Congenital Nose, Cleft Primary Palate, and Lip Disorders. Vet Clin North Am Small Anim Pract. 2016 Jul;46(4):663-75.

Wolf ZT, Leslie EJ, Arzi B,et al. A LINE-1 insertion in DLX6 is responsible for cleft palate and mandibular abnormalities in a canine model of Pierre Robin sequence. PLoS Genet. 2014 Apr 3;10(4):e1004257.