A greater severity of TREM2 dysfunction is associated with TREM2 variants pathogenic for both NHD and FTD: nonsense p.Q33X variant introduces a premature stop codon, halting TREM2 expression; p.T66M and p.Y38C variants, residing in the Ig fold, lead to deficits in TREM2 protein folding, maturation, and expression (145, 146). This evidence concerns the gene TREM2 and frontotemporal dementia.