Comments on Possible Mode of Inheritance of PLE/PLN
Following Dr. Giger's presentation at Soft Coated Wheaten Terrier Club of America dinner during MCKC 1999, questions arose from the audience about the possible mode of inheritance of PLE/PLN, Dr. Giger kindly agreed to have these email remarks placed on the SCWTCA web site.
Email 11-02-99 sent to Bonnie O'Connor
Published by permission of author
During the discussion after my presentation, it became evident that a large number of breeders are concerned with the offspring of Dockers [or any affected sire/dam]. In my presentation, I indicated that although PLE/PLN appears to be very common in the Soft Coated Wheaten Terrier, we do not know the mode of inheritance at the present time.
Potential modes of inheritance to consider include autosomal dominant, autosomal recessive, and complex inheritance. It is likely that external factors such as the environment and diet may affect the clinical presentation and onset of this disease. Because we do not know the mode of inheritance it is possible that Dockers' offspring might be affected, carriers, or clear.
- If this is a recessively inherited disease, then all offspring of Dockers would be carriers or affected depending on to whom they were bred.
- If this is a dominantly inherited disease, Dockers' offspring could be affected or clear. By definition, dominant trades do not have any carriers.
- If this is a complex inherited disease with one or more genes involved, Dockers' offspring may be affected, carriers, or clear.
The fact that the problem of PLE/PLN represents a genetic predisposition rather than a genetic disease complicates the situation as some animals may look like they are healthy but in fact carry the mutant gene(s) that will result in the disease when exposed to a particular carrier.
It is evident that there is a need for additional clinical investigation to further elucidate the mode of inheritance, to assess the validity of various diagnostic tests in predicting future disease, to study the disorder at the cellular and molecular levels, and to find ways to best manage affected Soft Coated Wheaten Terriers.