TREM2 and Nasu-Hakola disease: TREM2 sequence variants are the genetic basis for an autosomal recessive disorder called polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), also known as Nasu‐Hakola disease (Bianchin et al., 2004; Guerreiro et al., 2013).