This report describes dilated cardiomyopathy 1NN (CMD1NN), which is a subtype of dilated cardiomyopathy; CMD1NN exhibits an autosomal dominant pattern of inheritance. The human gene implicated in this disease is RAF1, which encodes the Raf-1 proto-oncogene, serine/threonine kinase. RAF1 is also associated with the diseases Noonan syndrome with multiple lentigines 2 (OMIM:611554, FBhh0000132) and Noonan syndrome 5 (OMIM:611553, FBhh0000131).
This specific disease has not been modeled in flies. For information about a disease model for cardiomyopathy related to RAF, see the human disease model report 'cardiomyopathy, hypertrophic (postulated), RAF-related' (FBhh0000737).
[updated Aug. 2020 by FlyBase; FBrf0222196]
Nonsyndromic isolated dilated cardiomyopathy (DCM) is characterized by left ventricular enlargement and systolic dysfunction, a reduction in the myocardial force of contraction. DCM usually presents with any one of the following: (1) Heart failure with symptoms of congestion (edema, orthopnea, paroxysmal nocturnal dyspnea) and/or reduced cardiac output (fatigue, dyspnea on exertion); (2) arrhythmias and/or conduction system disease; (3) thromboembolic disease (from left ventricular mural thrombus) including stroke. [from Dilated Cardiomyopathy Overview, pubmed:20301486 2016.01.26]
Dilated cardiomyopathy (CMD) is characterized by cardiac dilatation and reduced systolic function. CMD is the most frequent form of cardiomyopathy and accounts for more than half of all cardiac transplantations performed in patients between 1 and 10 years of age. A heritable pattern is present in 20 to 30% of cases. Most familial CMD pedigrees show an autosomal dominant pattern of inheritance, usually presenting in the second or third decade of life (summary by Levitas et al., 2010, pubmed:20551992). [from OMIM:115200, 2016.01.27]
[CARDIOMYOPATHY, DILATED, 1NN; CMD1NN](https://omim.org/entry/615916)
[RAF1 PROTOONCOGENE, SERINE/THREONINE KINASE ; RAF1](https://omim.org/entry/164760)
Of 10 patients in whom age of onset was known, 8 presented in childhood or adolescence. The average age at presentation was 12.6 years, which the authors noted was younger than the approximate average of 20 years associated with CMD caused by sarcomeric gene mutations (Dhandapany et al., 2014, pubmed:24777450). [From OMIM:615916, 2016.01.28]
RAF1 is a serine-threonine kinase that activates MEK1 (OMIM:176872) and MEK2 (OMIM:601263). Ectopically expressed RAF1 mutants from the two hypertrophic cardiomyopathy (CMH; see OMIM:192600) hotspots (around ser259 or ser612) linked to LEOPARD syndrome 2 and/or Noonan syndrome 5 had increased kinase activity and enhanced ERK (see 176948) activation, whereas non-CMH-associated mutants were kinase impaired. (Pandit et al., 2007, pubmed:17603483). Mutations in the CR2 domain, but not the CR3 domain, of RAF1 are associated with hypertrophic cardiomyopathy (Razzaque et al., 2007, pubmed:17603482). [From OMIM:611553 and OMIM:164760, 2016.01.19]
Many to one: 3 human to 1 Drosophila.