Hereditary cerebral hemorrhage with amyloidosis (HCHWA), Iowa type is a form of HCHWA (see this term) characterized by age of onset between 50-66 years of age, memory impairment, myoclonic jerks, expressive dysphagia, short-stepped gait, personality changes and lobar intracerebral hemorrhages.
It has been described in one American and one Spanish family.
HCHWA, Iowa type is due to a mutation in the APP gene on chromosome 21q21.2, encoding the beta-amyloid precursor protein. This mutation causes an increased accumulation of amyloid-beta protein in the walls of the arteries and capillaries of the meninges, cerebellar cortex and cerebral cortex, leading to the weakening and eventual rupture of these vessels.
Transmission is autosomal dominant.
Last update: February 2013
- Dr Joost HAAN
- Dr Gisela TERWINDT