Dilated Cardiomyopathy 2 (DCM2)
Dilated Cardiomyopathy, DCM
Dilated Cardiomyopathy (DCM) causes the heart to dilate to improve output which prevents heart muscle cells from contracting normally. The dilation seen during disease progression leads to increased pressure within the heart and eventual heart failure. Almost half of dogs diagnosed with this disease do not survive beyond a few months. DCM1 was the first mutation determined to lead to this disease. A second mutation called DCM2 has been identified. Dogs carrying both the DCM1 and DCM2 mutations are at highest risk for the disease. Although testing for the DCM1 and DCM2 mutations can be used as a guide for diagnosing the disease, it is recommended to use echocardiogram testing at 1 – 2 years along with a baseline Holter monitor test to confirm disease presence and progression. It is also recommended that dogs in breeding programs be physically tested every six months to determine disease status. It is important to note that both the DCM1 and DCM2 mutations are autosomal dominant with variable penetrance which means that only one copy of the mutated gene is necessary to cause DCM but due to its variable penetrance some positive dogs may never develop signs of the disease. It has been shown that dogs carrying a copy of both mutations (DCM1 and DCM2) are at the highest risk for disease progression.
Reading Your Results
A. (CLEAR/NORMAL):
These dogs have two copies of the normal gene and will neither develop Dilated Cardiomyopathy nor pass this mutation to their offspring.
B. (CARRIER/AFFECTED):
These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They can develop Dilated Cardiomyopathy and will, if bred, pass the mutation to 50% of its offspring, on average.
C. (AT RISK/AFFECTED):
These dogs have two copies of the mutation associated with this disease which can result in Dilated Cardiomyopathy. It is important to note that the presence or absence of the additional DCM1 mutation can affect a dog’s chances of disease progression.
Additional Details
Inheritances
Autosomal Dominant With Incomplete Penetrance
Affected gene
TTN (Aka TITIN)
Chromosome
Ch. 36
Mutation
G.22321955 C>T (CanFam 3.1)
Publication:
Meurs KM, Friedenberg SG, Kolb J, Saripalli C, Tonino P, Woodruff K, Olby NJ, Keene BW, Adin DB, Yost OL, DeFrancesco TC, Lahmers S, Tou S, Shelton GD, Granzier H. A missense variant in the titin gene in Doberman pinscher dogs with familial dilated cardiomyopathy and sudden cardiac death. Hum Genet. 2019 May;138(5):515-524. [PubMed: 30715562]
