Objective—To evaluate the coding region of the cardiac
actin gene in Doberman Pinschers with dilated
cardiomyopathy (DCM) for mutations that could be
responsible for the development of the condition
Animals—28 dogs (16 Doberman Pinschers with
DCM and 12 mixed-breed control dogs).
Procedure—Ten milliliters of blood was collected
from each dog for DNA extraction.
Polymerase chain reaction (PCR) primers were
designed to amplify canine exonic regions, using the
sequences of exons 2 to 6 of the cardiac actin gene.
Single-stranded conformational polymorphism analysis
was performed for each exon with all samples.
Autoradiographs were analyzed for banding patterns
specific to affected dogs. The DNA sequencing was
performed on a selected group of affected and control
Results—Molecular analysis of exons 2 to 6 of the
cardiac actin gene did not reveal any differences in
base pairs between affected dogs and control dogs
selected for DNA evaluation.
Conclusions—Mutations in exons 5 and 6 of the cardiac
actin gene that have been reported in humans
with familial DCM do not appear to be the cause of
familial DCM in Doberman Pinschers. Additionally,
evaluation of exons 2 to 6 for causative mutations did
not reveal a cause for inherited DCM in these
Doberman Pinschers. Although there is evidence that
DCM in Doberman Pinschers is an inherited problem,
a molecular basis for this condition remains unresolved.
Evaluation of other genes coding for
cytoskeletal proteins is warranted. ( Am J Vet Res
Objective—To evaluate the potential importance of
dystrophin, α-sarcoglycan (adhalin), and β-dystroglycan,
by use of western blot analysis, in several breeds
of dogs with dilated cardiomyopathy.
Sample Population—Myocardial samples obtained
from 12 dogs were evaluated, including tissues from
7 dogs affected with dilated cardiomyopathy, 4 control
dogs with no identifiable heart disease (positive control),
and 1 dog affected with Duchenne muscular dystrophy
(negative control for dystrophin). Of the affected
dogs, 4 breeds were represented (Doberman
Pinscher, Dalmatian, Bullmastiff, and Irish
Procedure—Western blot analysis was used for evaluation
of myocardial samples obtained from dogs
with and without dilated cardiomyopathy for the presence
of dystrophin and 2 of its associated glycoproteins,
α-sarcoglycan and β-dystroglycan.
Results—Detectable differences were not identified
between dogs with and without myocardial disease in
any of the proteins evaluated.
Conclusions and Clinical Relevance—Abnormalities
in dystrophin, α-sarcoglycan, and β-dystroglycan proteins
were not associated with the development of
dilated cardiomyopathy in the dogs evaluated in this
study. In humans, the development of molecular biological
techniques has allowed for the identification of
specific causes of dilated cardiomyopathy that were
once considered to be idiopathic. The use of similar
techniques in veterinary medicine may aid in the identification
of the cause of idiopathic dilated cardiomyopathy
in dogs, and may offer new avenues for therapeutic
intervention. ( Am J Vet Res 2001;62:67–71)