The Scottish Deerhound Club of America has had an osteosarcoma study going for a number of years at the U of TN. DNA samples were collected along with pedigrees and osteosarcoma status. Of special interest were DNA samples from dogs who had reached age 10 while remaining cancer-free.
The veterinarian conducting the research is:
Jeffrey Phillips DVM MSpVM PhD
Associate Professor of Oncology
C247 Veterinary Teaching Hospital
College of Veterinary Medicine
University of Tennessee at Knoxville
Knoxville, TN 37914
Phone: 865-974-8387
Fax: 865-974-5554
From one of Dr. Phillips's interim reports:
The pedigree information has expanded to approximately 3000 dogs, which includes approximately 400 dogs that developed osteosarcoma.
The male:female ratio of affected dogs is about 1:2, suggesting that females are more likely to be affected than males. This mirrors our findings in the Deerhound Health Survey done in the 1990s, which included data from about 400 dogs.
The average age of onset is about 8 years old. Again, this mirrors prior results from various surveys, including ones done by the Deerhound Club in the UK and our own Deerhound Health Survey. This late age of onset may indirectly explain the difference in osteosarcoma risk between males and females. If males are more likely than females to die of other causes at a relatively young age, then that would leave more older females than males at risk for osteosarcoma. The Deerhound Health Survey suggested that males are more likely than females to die of cardiomyopathy at a relatively young age.
Analysis of inbreeding and marriage loops reveals a strong inter-sibling correlation, which suggests a high likelihood that osteosarcoma risk is governed by a single gene in Deerhounds. There is also a strong mother-son correlation, but the father-son correlation is much weaker. Taken together, these findings suggest that the mode of inheritance may be more complicated than a simple dominant or recessive. In other words, the story of how osteosarcoma risk is inherited is not as simple as hoped.
Further DNA analysis is not prudent until the mode of inheritance can be pinned down with more certainty. If the mode of inheritance is known, then it probably would take only a small number of additional DNA analyses to identify a genetic marker. If the mode of inheritance is unknown, one can still search for a marker, but doing so requires a large number of additional DNA analyses and a correspondingly larger amount of time and money. Indeed, our database, large as it is, may be inadequate to identify a genetic marker unless we can work out the mode of inheritance.
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