Cleft Lip/Palate and Syndactyly (CLPS) in the Nova Scotia Duck Tolling Retriever (NSDTR)
Cleft palate is a hole (cleft) in the roof of the mouth (palate) that occurs during development of the puppy. Puppies are born with cleft palate. Cleft Lip is split in the lip and can occur on one or both sides of the mouth. Syndactyly is fusion of the middle two digits of the feet. The NSDTR breed has multiple genetic causes of cleft palate. A mutation test is already available for CP1 in the NSDTR which causes cleft palate. We have recently identified the mutation that causes a second form of cleft lip and cleft palate called CLPS. This mutation test is BREED specific and does not apply to any breed except the NSDTR. If you have a puppy with cleft palate from another breed and wish to participate in the identification of the genes responsible please contact the Bannasch Laboratory at the University of California at Davis (ztwolf@ucdavis.edu).
Discovery:
Scientists from the Bannasch Laboratory at the University of California, Davis and the Wade Laboratory from the University of Sydney have discovered the genetic cause of a second form of cleft palate in the Nova Scotia Duck Tolling Retriever. Dogs with this form of cleft palate have an inactivating mutation in a gene important in normal development. The mutation is not present in any other breeds of dogs based on testing over 80 breeds and over 300 individual animals.
The mode of inheritance:
CLPS is inherited as an autosomal recessive disease meaning that affected puppies inherited two mutant copies of this gene one from each of their parents. The phenotype of puppies with two copies of CLPS can vary from cleft palate only to cleft lip and cleft palate and in both cases puppies can have syndactyly but don’t always. One case had a cleft nose and syndactyly. A summary of the variation in the clinical presentation of two copies of the CLPS mutations is shown below.
| Cleft Type |
Syndactyly |
|
Yes |
No |
Total |
Cleft Palate |
0 |
1 |
1 |
Cleft Nose |
1 |
0 |
1 |
Cleft Nose/Palate |
5 |
0 |
5 |
Cleft Lip/ Palate |
2 |
0 |
2 |
Cleft Lip/Nose/Palate |
0 |
4 |
4 |
None |
1 |
0 |
1 |
Total |
9 |
5 |
14 |
The test:
CLPS N/N: This dog has two normal copies of CLPS
CLPS N/A: This dog has one mutant (abnormal) copy of CLPS
CLPS A/A: This dog has two mutant (abnormal) copies of CLPS
Counseling:
CLPS is inherited as an autosomal recessive disease meaning that animals that are N/A are normal but can produce affected puppies if bred to another carrier (N/A). There are ~ 2% of Tollers that carry CLPS (N/A) at the time the test was released, however this number can change each generation. We have received 36 samples from cleft puppies from North America in the NSDTR and 14 of those were caused by CLPS. Dogs that are carriers (N/A) are completely normal themselves and can be safely bred to N/N dogs in order to maintain diversity within the breed and select for other positive attributes in carrier dogs. Puppies affected with cleft palate will be tested at no charge. Please contact Zena Wolf for more details (ztwolf@ucdavis.edu).
