A genome-wide association study of mitochondrial DNA copy number in two population-based cohorts

Table 1 Description of study groups and analysis structure in this paper

Cohort	Group	% female	Source of DNA	Age at DNA assay	Site of assay	Covariates in baseline model	Cell proportions source	Cell proportions included in sensitivity model	N (N [CC]) main analysis	N (N [CC]) by subgroups	Meta-analyses (MA) in which each group features
ALSPAC	Mothers^a(antenatal)	100%	White cells or whole blood [phenol-chloroform extracted]	16–43 years	Bristol	Age, DNA concentration, PC1, PC2, sample type (white cell or whole blood)	Estimated for a subset from Illumina 450 k methylation data	Lymphocytes and neutrophils	5461 (546) (All DNA sources)	2056 (245) [Whole blood samples] 3405 (301) [White cell samples]	MA1 [main] all mothers MA2 [sensitivity] white cell mothers only
	Children^b	49%	Whole blood [salt-extracted]	6–9 years	Bristol	Age, sex, DNA concentration, PC1, PC2		Lymphocytes, monocytes, and neutrophils	NA	2102 (80)	–
	Neonates^b	44%	White cells [phenol-chloroform extracted]	0 years	Bristol	Sex, DNA concentration, PC1, PC2		Lymphocytes, monocytes, and granulocytes	NA	3647 (606)	–
UKBS	Female^a	50%	White cells [guanidine-chloroform extracted]	17–69 years	Newcastle	Age, PC1–PC4	Derived from full blood counts^c	Lymphocytes and neutrophils	1338 (1138) [Females only]	–	MA1 [main] females only MA2 [sensitivity] females only
UKBS	Male	50%	White cells [guanidine-chloroform extracted]	17–69 years	Newcastle	Age, PC1–PC4	Derived from full blood counts^c	Lymphocytes and neutrophils	NA	1333 (1122) [Males]	–

CC cell composition adjusted model
^aGroup used in the main meta-analyses
^bChildren and neonates in these secondary analyses are unrelated to each other at IBD > 0.125, but some are related to the ALSPAC mothers (see ‘Genotype data’ in the ‘Participants and methods’ section)
^cSee Nalls et al. [27]; Gieger et al. [46]

ISSN: 1479-7364