Cleft Palate Nova Scotia Duck Tolling Retriever Type
Cleft Palate Nova Scotia Duck Tolling Retriever type, also known as Cleft Lip / Palate and Syndactyly (CLPS) is a genetic disorder specific to affect Nova Scotia Duck Tolling Retrievers. It is a craniofacial birth defect characterized by a hole (cleft) in the roof of the mouth (palate) developed in a puppy during embryonic development. The disorder occurs also in human patients, and it is a most commonly occurring craniofacial human birth defect. Usually, it is accompanied with a hearing loss, difficulties with speech and eating, and increased risk for neurological disorders. In dogs, cleft palate most commonly affects beagles, dachshunds, cocker spaniels, German shepherds, Labrador retrievers, and short-nosed breeds, such as Pekingese. Although genetic heritage is the primary cause of occurrence of this disorder, nutritional deficiencies, viruses, and poisons exposure during pregnancy may also increase the risk. The genetic cause of the disorder has been identified in Nova Scotia Duck Tolling Retrievers.
Characteristics and Symptoms
The palate is the roof of the mouth in mammals. Anatomical structure that divides the nasal cavity from the oral cavity is known as the secondary palate. When there is a failure in any of the pathways of the development of the secondary palate, cleft palate occurs. CP can be divided as nonsyndromic (no other anomalies accompany the disorder) and syndromic (there are other abnormalities present as well).
Affected Nova Scotia Duck Tolling Retrievers can be recognized by a cleft palate, shortened mandible, and posteriorly placed tongue, which makes their CP a syndromic type since there are other abnormalities present next to cleft palate.
Symptoms may include a runny nose, coughing, aspiration pneumonia (pneumonia caused by milk and food contents entering the cleft and infecting the lungs, lack of appetite, slow growth and weight loss. Puppies show difficulties while drinking and nursing.
The disorder is caused by a mutation within the regulatory region of the DLX6 gene, which play an important role in the embryological development. The disorder is inherited in an autosomal recessive pattern. Healthy parents of an affected dog are obligate heterozygotes and therefore carry one mutant allele. Heterozygotes have no symptoms. At conception, each cub has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
Wolf, Z. T. et al. (2014): 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. doi: 10.1371/journal.pgen.1004257. eCollection 2014 Apr.