Biallelic mutations in TMEM126B cause severe complex I deficiency with a variable clinical phenotype

Alston, CL; Compton, AG; Formosa, LE; Strecker, V; Olahova, M; Haack, TB; Smet, J; Stouffs, K; Diakumis, P; Ciara, E; Cassiman, D; Romain, N; Yarham, JW; He, L; De Paepe, B; Vanlander, AV; Seneca, S; Feichtinger, RG; Ploski, R; Rokicki, D; Pronicka, E; Haller, RG; Van Hove, JL; Bahlo, M; Mayr, JA; Van Coster, R; Prokisch, H; Wittig, I; Ryan, MT; Thorburn, DR; Taylor, RW

Author(s): Alston, CL; Compton, AG; Formosa, LE; Strecker, V; Olahova, M; Haack, TB; Smet, J; Stouffs, K; Diakumis, P; Ciara, E; Cassiman, D; Romain, N; Yarham, JW; He, L; De Paepe, B; Vanlander, AV; Seneca, S; Feichtinger, RG; Ploski, R; Rokicki, D; Pronicka, E; Haller, RG; Van Hove, JL; Bahlo, M; Mayr, JA; Van Coster, R; Prokisch, H; Wittig, I; Ryan, MT; Thorburn, DR; Taylor, RW;
Details: Publication Year 2016-07-07,Volume 99,Issue #1,Page 217-27
Journal Title: Am J Hum Genet
Publication Type: Journal Article
Abstract: Complex I deficiency is the most common biochemical phenotype observed in individuals with mitochondrial disease. With 44 structural subunits and over 10 assembly factors, it is unsurprising that complex I deficiency is associated with clinical and genetic heterogeneity. Massively parallel sequencing (MPS) technologies including custom, targeted gene panels or unbiased whole-exome sequencing (WES) are hugely powerful in identifying the underlying genetic defect in a clinical diagnostic setting, yet many individuals remain without a genetic diagnosis. These individuals might harbor mutations in poorly understood or uncharacterized genes, and their diagnosis relies upon characterization of these orphan genes. Complexome profiling recently identified TMEM126B as a component of the mitochondrial complex I assembly complex alongside proteins ACAD9, ECSIT, NDUFAF1, and TIMMDC1. Here, we describe the clinical, biochemical, and molecular findings in six cases of mitochondrial disease from four unrelated families affected by biallelic (c.635G>T [p.Gly212Val] and/or c.401delA [p.Asn134Ilefs( *)2]) TMEM126B variants. We provide functional evidence to support the pathogenicity of these TMEM126B variants, including evidence of founder effects for both variants, and establish defects within this gene as a cause of complex I deficiency in association with either pure myopathy in adulthood or, in one individual, a severe multisystem presentation (chronic renal failure and cardiomyopathy) in infancy. Functional experimentation including viral rescue and complexome profiling of subject cell lines has confirmed TMEM126B as the tenth complex I assembly factor associated with human disease and validates the importance of both genome-wide sequencing and proteomic approaches in characterizing disease-associated genes whose physiological roles have been previously undetermined.
Publisher: Cell Press
Research Division(s): Population Health And Immunity
PubMed ID: 27374774
Publisher's Version: https://doi.org/10.1016/j.ajhg.2016.05.021
Open Access at Publisher's Site: http://www.sciencedirect.com/science/article/pii/S0002929716301562
NHMRC Grants: NHMRC/1102971, NHMRC/1054618,
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2016-08-10 04:12:48

Last Modified: 2016-08-10 04:22:17