Orphanet rare-disease nomenclature identifier Orphanet_324723 (Hereditary cerebral hemorrhage with amyloidosis, Arctic type) can be described as follows. Hereditary cerebral hemorrhage with amyloidosis (HCHWA), Arctic type is a form of HCHWA (see this term) characterized by an age of onset of 54-61 years and progressive Alzheimer's disease-like dementia, without intracerebral hemorrhages. Also known as: HCHWA, Arctic type.