TREM2 and Alzheimer disease: For example, an Alzheimer’s disease variant in the TREM2 gene (rs75932628) was also correlated with amyotrophic lateral sclerosis (Cady et al., 2014), while a variant in the MARK2 gene (rs10792421) was associated with Alzheimer’s disease and bipolar disorder (Drange et al., 2019).