Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), or Nasu-Hakola disease is an autosomal recessive inherited disorder. It is characterized by repeated fractures occurring during adolescence and progressive presenile dementia in the fourth decade. The disease is caused by a mutation in the TREM2 or DAP12 gene that regulates osteoclast differentiation. TREM2-DAP12 is also expressed by microglia, thus neurological impairments seen in this disease are considered to be directly caused by microglial dysfunction.
