ABeta amyloidosis, Dutch type, (Hereditary cerebral hemorrhage with amyloidosis, Dutch type) is a special type of HCHWA and is a group of familial disorders of the central nervous system characterized by amyloid deposits in the main blood vessels. This results in focal neurological deficits, continuous cognitive decline leading to dementia and strokes.
The age of onset is between 39 and 76 years, and the disease begins with a hemorrhagic stroke. As a result of the first seizure, about 1/3 of the patients die. The remaining 2/3 often suffer severe disabilities, with strokes being relapsing. The cognitive decline usually begins after the first or later attacks and reaches in most patients from the age of 40 dementia. Half of the patients suffer from epilepsy following a previous attack.
The cause was a mutation in the APP gene at the 21q21.2 locus, which encodes the beta-amyloid precursor protein. In the meningocortical arterioles, there is an increased deposition of amyloid-beta, which weakens them and ultimately leads to a rupture.
The disease has so far only been manifested in Dutch families, most of them near Katwijk. However, some cases have occurred in the US and Australia by immigrant families.
The disease is often fatal from the first onset of symptoms until 10 years later.