ADDISON'S Disease

ADDISON’S Disease RESEARCH
© LeoLetter Vol. 14, No. 3, 1998 / LCA
Submitted by Health-Comm. LCA

WHAT IS ADDISON’S Disease ?
Addison’s Disease is an immune system disorder, develops when the Adrenal Gland becomes non-functional. If not diagnosed and treated properly it will be fatal. Unfortunately, it can’t be diagnosed until it’s „full blown“,
usually in mid-life. It is often accompanied by Hypothyroidism.

It appears

In humans ... 1 : 100.000 (Pres. Kennedy had it)
In the dog ... 1 : 1.000 = 100 times more than in humans
In the Leonberger ... 1 : 100 and potentially climbing quickly
In the Bearded Collie ... 1 : 20 – 1 : 10 in several others

Study/research see Information Letter below.

Marker-Identification – Dr. Wagner is interested to find DNA-markers for AD -
Identification of the markers on the DNA will mean that a simple blood draw from puppies, before they leave the breeder, can be coded to indicate if the puppy will be free, a carrier or will get the Disease when it ages. AD will then be quickly eliminated forever!
Today it’s a guessing game since the mode of inheritance is unknown.

 

Informative letter on Addison’s Study in Leonbergers by Dr. Ry Wagner
© Professor of Biology, Institut of Molecular Biology, University of Oregon, submitted by Mrs. W. Zieher,
Health-Comm. LCA, taken from LeoLetter Vol. 14, No. 4, 1998/LCA

The study of Addison’s Disease is based on the scientific principles of modern genetics that permit the analysis of complex traits, even with very few affected individuals involved in the study.

Question: Is there a genetic basis for Addison’s Diseasee in the Leonberger, and is there a real risk to the breed from the spread of Addison’s Diseasee ?

The existing data from other breeds strongly supports the conclusion that Addison’s D. is inherited in the dog as a polygenic (i.e. multiple gene) trait, however only a fraction of animals predisposed to A.D. display the Disease.
What environmental or physiological factors determine this „threshold of appearance“ is unclear but one possiblity discussed in the literature is stress.

Polygenic traits have been a difficult area for study until very recently. The creation and use of molecular (DANN) markers for the inheritance of specific chromosomal regions, combined with the development of powerful mathematical models for polygenic inheritance, has allowed the determination of the genetic basis of many complex traits.
Advances in this area of research include the genetic basis of many types of cancer and the genetic basis of several behaviors, as well as the genetic basis of Diseases.