polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), presenile dementia with bone cysts; Nasu-Hakola disease

Epidemiology

• ~160 cases, mainly in Finland & Japan
• onset third decade

Pathology

• basal ganglia calcification
• gliosis
• white matter demyelination
• senile plaques
• neurofibrillary tangles Clinical features:
• skeletal changes
  • epiphyseal bone cysts, restricted to ankle & wrist
  • polycystic osteodysplasia
  • fracture predisposition
• neurologic
  • dementia
  • impairment of memory
  • hyperreflexia
  • euphoria
  • agnostic-apractic-aphasic symptoms
  • myoclonic twitches
  • seizure
• psychosis

Genetics

• autosomal recessive
• mutations in TREM2 gene
• defects in TYROBP

Differential diagnosis

• Alzheimer's disease
• fibrous dysplasia of bone

More general terms

• genetic disease of the central nervous system
• neurodegenerative disease

Additional terms

• triggering receptor expressed on myeloid cells 2; triggering receptor expressed on monocytes 2 (TREM2)

Database

• OMIM: https://mirror.omim.org/entry/221770
• OMIM: https://mirror.omim.org/entry/604142