Untersuchungen zu familiären und rassespezifischen ...

7 Evaluation of selective cobalamin malabsorption caused
by mutations in the amnionless gene as a part of the
lundehund-syndrome
Abstract
A gastroenteropathy (GE) of unknown etiology is prevalent in Norwegian lundehunds.
The frequent occurrence and familiarity suggest a genetic background of this
disease. A typical finding in GE-affected lundehunds is a deficiency of cobalamin.
Deficiencies of cobalamin can be caused by mutations in the AMN gene. We
scanned four GE-affected and 13 unaffected lundehunds for mutations in AMN.
Moreover, AMN flanking SNPs and microsatellites were tested for co-segregation
with GE, and coding sequences of AMN were scanned for mutations. We could not
identify any mutation in the coding sequence of AMN. Linkage and association test
statistics were not significant. Therefore, AMN can be excluded as a candidate gene
for the pathogenesis of GE in Norwegian lundehunds.
Introduction
In the Norwegian lundehund (also known as Puffin dog) a chronic form of
gastroenteropathy (GE; “lundehund-syndrome” or “lundehund-gastroenteropathy”) is
prevalent. This GE causes intestinal loss of proteins (Williams et al., 1997). There are
different possible causes for this kind of enteropathy discussed, such as
inflammatory bowel disease, mucosal lesions or primary and secondary
lymphangiectasia. Clinical signs are diarrhea, vomitus, ascites and subcutaneous
oedema (Peterson et al., 2003). Histopathological findings are chronic atrophic