MOGE(S) classification for cardiomyopathies

MOGE(S) classification for cardiomyopathies

MOGE(S) classification for cardiomyopathies: Conventionally cardiomyopathies have been classified into hypertrophic, restrictive and dilated varieties [1]. This classification is based on the phenotype rather than the genotype. With advances in genetic studies, several genes related to cardiomyopathies have been described. Hence in 2013, World Heart Federation proposed a classification including the genotype and phenotype of cardiomyopathies called as MOGE(S) classification [2]. This system of classification resembles the TNM classification for malignant neoplasms [3].

The reason for adding genotype information to the classification was the difference in risks associated with various genetic patterns. Arrhythmic risk was higher in troponinopathies even without severe left ventricular wall thickness [4]. In laminopathies arrhythmic risk may manifest even before severe left ventricular dysfunction [5]. But dystrophinopathies have lower arrhythmic risk in spite of gross left ventricular enlargement and dysfunction [6].
MOGE(S) nomenclature system has 5 attributes:

• M: Morphofunctional characteristic

• O: Organ involvement

• G: Genetic or familial inheritance pattern

• E: Etiological annotation

• S: Functional status using stages A-D of American College of Cardiology/American Heart Association (ACC/AHA) staging, and classes I-IV using New York Heart Association (NYHA) functional classification.

M_D stands for dilated cardiomyopathy, M_H for hypertrophic cardiomyopathy, M_A for arrhythmogenic right ventricular cardiomyopathy, M_R for restrictive cardiomyopathy and M_LNVC for left ventricular noncompaction.
O_H stands for heart only, O_H+M for heart and skeletal muscle, O_H+A for heart and nervous system and so on.
G_AD stands for autosomal dominant, G_AR for autosomal recessive, G_XL for X-linked and so on.
E_G stands for genetic etiology with sub groups like E_{G-MYH7[p. Arg403Glu]} for one variety of hypertrophic cardiomyopathy.
Adding the functional status, M_HO_HG_ADE_{G-MYH7[p. Arg403Glu]}S_B-I would stand for a variety of hypertrophic cardiomyopathy in heart failure stage B and functional class I. Other varieties of cardiomyopathies can be comprehensively classified on these lines if all the information required are available for a particular patient.

References

1. Goodwin JF, Oakley CM. The cardiomyopathies. Br Heart J. 1972 Jun;34(6):545-52.
2. Arbustini E, Narula N, Dec GW, Reddy KS, Greenberg B, Kushwaha S, Marwick T, Pinney S, Bellazzi R, Favalli V, Kramer C, Roberts R, Zoghbi WA, Bonow R, Tavazzi L, Fuster V, Narula J. The MOGE(S) classification for a phenotype-genotype nomenclature of cardiomyopathy: endorsed by the World Heart Federation. J Am Coll Cardiol. 2013 Dec 3;62(22):2046-72.
3. Şahan E, Şahan S, Karamanlıoğlu M, Gul M, Tufekcioğlu O. The MOGE(S) classification : A TNM-like classification for cardiomyopathies. Herz. 2016 Sep;41(6):503-6.
4. Sorajja P, Elliott PM, McKenna WJ. The molecular genetics of hypertrophic cardiomyopathy: prognostic implications. Europace. 2000;2:4-14.
5. van Rijsingen IA, Arbustini E, Elliott PM, Mogensen J, Hermans-van Ast JF, van der Kooi AJ, van Tintelen JP, van den Berg MP, Pilotto A, Pasotti M, Jenkins S, Rowland C, Aslam U, Wilde AA, Perrot A, Pankuweit S, Zwinderman AH, Charron P, Pinto YM. Risk factors for malignant ventricular arrhythmias in lamin a/c mutation carriers a European cohort study. J Am Coll Cardiol. 2012;59:493-500.
6. Diegoli M, Grasso M, Favalli V, et al. Diagnostic work-up and risk stratification in X-linked dilated cardiomyopathies caused by dystrophin defects J Am Coll Cardiol. 2011;58:925-934.