TREM2 and Nasu-Hakola disease: Homozygous TREM2 mutations, including early stop codons (E14X, Q33X, W44X, W78X) [24–27] and missense mutations in the immunoglobulin-like ectodomain (Y38C, W50C, T66M, V126G) [24, 28, 29], are primarily linked to NHD, a rare disorder characterized by early-onset dementia, demyelination, and bone cysts.