@article {9502,
	title = {Association Between Whole Blood-Derived Mitochondrial DNA Copy Number, Low-Density Lipoprotein Cholesterol, and Cardiovascular Disease Risk.},
	journal = {J Am Heart Assoc},
	year = {2023},
	month = {2023 Oct 07},
	pages = {e029090},
	abstract = {<p>Background The relationship between mitochondrial DNA copy number (mtDNA CN) and cardiovascular disease remains elusive. Methods and Results We performed cross-sectional and prospective association analyses of blood-derived mtDNA CN and cardiovascular disease outcomes in 27 316 participants in 8 cohorts of multiple racial and ethnic groups with whole-genome sequencing. We also performed Mendelian randomization to explore causal relationships of mtDNA CN with coronary heart disease (CHD) and cardiometabolic risk factors (obesity, diabetes, hypertension, and hyperlipidemia). <0.01 was used for significance. We validated most of the previously reported associations between mtDNA CN and cardiovascular disease outcomes. For example, 1-SD unit lower level of mtDNA CN was associated with 1.08 (95\% CI, 1.04-1.12; <0.001) times the hazard for developing incident CHD, adjusting for covariates. Mendelian randomization analyses showed no causal effect from a lower level of mtDNA CN to a higher CHD risk (β=0.091; =0.11) or in the reverse direction (β=-0.012; =0.076). Additional bidirectional Mendelian randomization analyses revealed that low-density lipoprotein cholesterol had a causal effect on mtDNA CN (β=-0.084; <0.001), but the reverse direction was not significant (=0.059). No causal associations were observed between mtDNA CN and obesity, diabetes, and hypertension, in either direction. Multivariable Mendelian randomization analyses showed no causal effect of CHD on mtDNA CN, controlling for low-density lipoprotein cholesterol level (=0.52), whereas there was a strong direct causal effect of higher low-density lipoprotein cholesterol on lower mtDNA CN, adjusting for CHD status (β=-0.092; <0.001). Conclusions Our findings indicate that high low-density lipoprotein cholesterol may underlie the complex relationships between mtDNA CN and vascular atherosclerosis.</p>},
	issn = {2047-9980},
	doi = {10.1161/JAHA.122.029090},
	author = {Liu, Xue and Sun, Xianbang and Zhang, Yuankai and Jiang, Wenqing and Lai, Meng and Wiggins, Kerri L and Raffield, Laura M and Bielak, Lawrence F and Zhao, Wei and Pitsillides, Achilleas and Haessler, Jeffrey and Zheng, Yinan and Blackwell, Thomas W and Yao, Jie and Guo, Xiuqing and Qian, Yong and Thyagarajan, Bharat and Pankratz, Nathan and Rich, Stephen S and Taylor, Kent D and Peyser, Patricia A and Heckbert, Susan R and Seshadri, Sudha and Boerwinkle, Eric and Grove, Megan L and Larson, Nicholas B and Smith, Jennifer A and Vasan, Ramachandran S and Fitzpatrick, Annette L and Fornage, Myriam and Ding, Jun and Carson, April P and Abecasis, Goncalo and Dupuis, Jos{\'e}e and Reiner, Alexander and Kooperberg, Charles and Hou, Lifang and Psaty, Bruce M and Wilson, James G and Levy, Daniel and Rotter, Jerome I and Bis, Joshua C and Satizabal, Claudia L and Arking, Dan E and Liu, Chunyu}
}
@article {9580,
	title = {Association analysis of mitochondrial DNA heteroplasmic variants: methods and application.},
	journal = {medRxiv},
	year = {2024},
	month = {2024 Jan 13},
	abstract = {<p>We rigorously assessed a comprehensive association testing framework for heteroplasmy, employing both simulated and real-world data. This framework employed a variant allele fraction (VAF) threshold and harnessed multiple gene-based tests for robust identification and association testing of heteroplasmy. Our simulation studies demonstrated that gene-based tests maintained an appropriate type I error rate at α=0.001. Notably, when 5\% or more heteroplasmic variants within a target region were linked to an outcome, burden-extension tests (including the adaptive burden test, variable threshold burden test, and z-score weighting burden test) outperformed the sequence kernel association test (SKAT) and the original burden test. Applying this framework, we conducted association analyses on whole-blood derived heteroplasmy in 17,507 individuals of African and European ancestries (31\% of African Ancestry, mean age of 62, with 58\% women) with whole genome sequencing data. We performed both cohort- and ancestry-specific association analyses, followed by meta-analysis on bothpooled samples and within each ancestry group. Our results suggest that mtDNA-Enco ded genes/regions are likely to exhibit varying rates in somatic aging, with the notably strong associations observed between heteroplasmy in the  and  genes (  <0.001) and advance aging by the Original Burden test. In contrast, SKAT identified significant associations (  <0.001) between diabetes and the aggregated effects of heteroplasmy in several protein-coding genes. Further research is warranted to validate these findings. In summary, our proposed statistical framework represents a valuable tool for facilitating association testing of heteroplasmy with disease traits in large human populations.</p>},
	doi = {10.1101/2024.01.12.24301233},
	author = {Sun, Xianbang and Bulekova, Katia and Yang, Jian and Lai, Meng and Pitsillides, Achilleas N and Liu, Xue and Zhang, Yuankai and Guo, Xiuqing and Yong, Qian and Raffield, Laura M and Rotter, Jerome I and Rich, Stephen S and Abecasis, Goncalo and Carson, April P and Vasan, Ramachandran S and Bis, Joshua C and Psaty, Bruce M and Boerwinkle, Eric and Fitzpatrick, Annette L and Satizabal, Claudia L and Arking, Dan E and Ding, Jun and Levy, Daniel and Liu, Chunyu}
}
