2.2 |. ADNI demographics and haplogroups

We used the ADNI cohort as a replication cohort. The ADNI was launched in 2003 as a public-private partnership, led by Michael W. Weiner, MD. The primary goal of ADNI has been to test whether serial magnetic resonance imaging (MRI), positron emission tomography (PET), other biological markers, and clinical and neuropsychological assessment can be combined to measure the progression of MCI and early AD. Descriptive and demographic characteristics of ADNI participants are recorded and accessible. Like the KUADC cohort, the ADNI cohort is longitudinal by design and group assignment can change over time. Only ADNI participants with an available complete mtDNA sequence were used in the present study. This subset of ADNI participants have undergone complete mtDNA sequencing and those sequences were used to assign mtDNA haplogroups.³⁷ There was no overlap between KUADC and ADNI subjects in this study.

ADNI participants are classified as AD, MCI, or CN. For this study, we considered only ADNI subjects who were AD or CN at the time of their initial visit, or AD or CN at the time of the last available diagnosis indicated in the publicly accessible database.