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. 2020 Mar 2;6(2):e402.
doi: 10.1212/NXG.0000000000000402. eCollection 2020 Apr.

Mitochondrial diseases in North America: An analysis of the NAMDC Registry

Affiliations

Mitochondrial diseases in North America: An analysis of the NAMDC Registry

Emanuele Barca et al. Neurol Genet. .

Abstract

Objective: To describe clinical, biochemical, and genetic features of participants with mitochondrial diseases (MtDs) enrolled in the North American Mitochondrial Disease Consortium (NAMDC) Registry.

Methods: This cross-sectional, multicenter, retrospective database analysis evaluates the phenotypic and molecular characteristics of participants enrolled in the NAMDC Registry from September 2011 to December 2018. The NAMDC is a network of 17 centers with expertise in MtDs and includes both adult and pediatric specialists.

Results: One thousand four hundred ten of 1,553 participants had sufficient clinical data for analysis. For this study, we included only participants with molecular genetic diagnoses (n = 666). Age at onset ranged from infancy to adulthood. The most common diagnosis was multisystemic disorder (113 participants), and only a minority of participants were diagnosed with a classical mitochondrial syndrome. The most frequent classical syndromes were Leigh syndrome (97 individuals) and mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (71 individuals). Pathogenic variants in the mitochondrial DNA were more frequently observed (414 participants) than pathogenic nuclear gene variants (252 participants). Pathogenic variants in 65 nuclear genes were identified, with POLG1 and PDHA1 being the most commonly affected. Pathogenic variants in 38 genes were reported only in single participants.

Conclusions: The NAMDC Registry data confirm the high variability of clinical, biochemical, and genetic features of participants with MtDs. This study serves as an important resource for future enhancement of MtD research and clinical care by providing the first comprehensive description of participant with MtD in North America.

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Figures

Figure 1
Figure 1. Genes mutated in the canonical mitochondrial syndromes studied
Gene pathogenic variants in North American Mitochondrial Disease Consortium Registry participants with canonical syndromes. cPEO = chronic progressive external ophthalmoplegia; LHON = Leber hereditary optic neuropathy; MELAS = mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes; MERRF = myoclonus epilepsy with ragged red fibers; mtDNA = mitochondrial DNA.
Figure 2
Figure 2. Nuclear gene pathogenic variant frequency in the North American Mitochondrial Disease Consortium Registry
Each square represents 1 participant.

References

    1. DiMauro S, Davidzon G. Mitochondrial DNA and disease. Ann Med 2005;37:222–232. - PubMed
    1. McFarland R, Taylor RW, Turnbull DM. A neurological perspective on mitochondrial disease. Lancet Neurol 2010;9:829–840. - PubMed
    1. Chinnery PF. Mitochondrial disorders overview. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews®. Seattle, WA: University of Washington, Seattle; 2014.
    1. Gorman GS, Schaefer AM, Ng Y, et al. . Prevalence of nuclear and mitochondrial DNA mutations related to adult mitochondrial disease. Ann Neurol 2015;77:753–759. - PMC - PubMed
    1. Thompson R, Robertson A, Lochmüller H. Natural history, trial readiness and gene discovery: advances in patient registries for neuromuscular disease. Adv Exp Med Biol 2017;1031:97–124. - PubMed