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 phenotye 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 asssociated 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 inspite of gross left ventricular enlargement and dysfunction [6].

MOGE(S) nomenclature system has 5 atttributes:

  • M: Morphofunctional characteristic

  • O: Organ involvement

  • G: Genetic or familial inheritence 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.

MD stands for dilated cardiomyopathy, MH for hypertrophic cardiomyopathy, MA for arrhythmogenic right ventricular cardiomyopathy, MR for restrictrive cardiomyopathy and MLNVC for left ventricular noncompaction.

OH stands for heart only, OH+M for heart and skeletal muscle, OH+A for heart and nervous system and so on.

GAD stands for autosomal dominant, GAR for autosomal recessive, GXL for X-linked and so on.

EG stands for genetic etiology with sub groups like EG-MYH7[p.?Arg403Glu] for one variety of hypertrophic cardiomyopathy.

Adding the functional status, MHOHGADEG-MYH7[p.?Arg403Glu]SB-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 classsified on these lines if all the informations 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 et al. 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. Sahan E et al. The MOGE(S) classification : A TNM-like classification for cardiomyopathies. Herz. 2016 Jan 25. [Epub ahead of print].
  4. Sorajja P, Elliott PM, McKenna WJ. The molecular genetics of hypertrophic cardiomyopathy: prognostic implications. Europace. 2000;2:4-14.
  5. 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.