@Article{chd.12634,
AUTHOR = {Katharina Niedermayr, Gerhard Pölzl, Sabine Scholl‐Bürgi, Christine Fauth, Ulrich Schweigmann, Edda Haberlandt, Ursula Albrecht, Manuela Zlamy, Wolfgang Sperl, Johannes A. Mayr, Daniela Karall},
TITLE = {Mitochondrial DNA mutation “m.3243A>G”—Heterogeneous clinical picture for cardiologists (“m.3243A>G”: A phenotypic chameleon)},
JOURNAL = {Structural and Congenital Heart Disease},
VOLUME = {13},
YEAR = {2018},
NUMBER = {5},
PAGES = {671--677},
URL = {http://www.techscience.com/schd/v13n5/39048},
ISSN = {3071-1738},
ABSTRACT = {Objective: In general, a mitochondrial disorder is diagnosed on the basis of symptom
combinations and confirmed by genetic findings. However, patients carrying the
m.3243A>G mutation in the mitochondrial tRNA leucine 1 (MT‐TL1) do not always
meet all the proposed criteria for the most frequently encountered mitochondrial
syndrome “MELAS,” an acronym for Mitochondrial Encephalomyopathy, Lactic
Acidosis, and at least one Stroke‐like episode. We here present various phenotypic
characteristics of the mitochondrial mutation m.3243A>G with particular focus on
cardiac manifestations.
Methods and Results: We followed nine patients (1 month to 68 years old; median
42 years; four female and five male) from nine different families with this m.3243A>G
mutation in the MT‐TL1. The classical “MELAS” criteria are met by only three of these
patients. Electrocardiography (ECG) shows preexcitation pattern with short PR intervals and delta waves (Wolff‐Parkinson‐White) in three patients and sick sinus syndrome plus atrioventricular block I in one patient. Hypertrophic cardiomyopathy was
found in eight patients with moderate to severe regurgitation of various valves.
Conclusion: Cardiac manifestation can encompass hypertrophic or dilated cardiomyopathy, as well as preexcitation syndromes or conduction delay. In general, the
clinical presentation to meet the “MELAS” criteria varies due to heteroplasmy. Thus,
cardiologists should screen patients with unexplained cardiac features in the context
of deafness, short stature and learning disabilities for mtDNA mutations, especially
the m.3243A>G mutation. A clear diagnosis is essential as a basis for prognostic advice concerning the disease course and clinical impact on family testing.},
DOI = {10.1111/chd.12634}
}