What is HCHWA-D?

The disease in short

"HCHWA-D is a hereditary form of cerebral haemorrhaging. The abbreviation stands for: Hereditary Cerebral Haemorrhage with Amyloidosis  - Dutch type. Doctors sometimes refer to it as Amyloid Angiopathy.

The disease is characterized by an accumulation of proteins (amyloid) in the blood vessels of the brain which causes brain haemorrhages."

The development of the disease

The first outward sign of the disease is the initial ‘stroke’- which usually occurs between the ages of 45 and 65 (average age is 50). Strokes have been recorded as early as age 39 and as late as 76. Reoccurring attacks, varying in frequency and severity can occur. The progression of HCHWA-D after the initial stroke is different for each individual patient (the reason for this is unknown):

• About one third of HCHWA-D patients die as a result of the effects of the first stroke.
• Patients who survive the initial haemorrhage, are often affected by recurring strokes. On average, 3 recurring strokes with a maximum of 10 recorded strokes.
• These haemorrhages can result in severe brain damage.
• The average life expectancy of a patient with HCHWA-D after the initial stroke is approximately 10 years (ranging up to 20 years).
• HCHWA-D can also be associated with dementia (vascular dementia).
• The number of haemorrhages and the age at which they initially occur can vary greatly- even within one family. 

Treatment for HCHWA-D

Unfortunately HCHWA-D is not curable and there is no known treatment (neither symptomatic nor preventive). Following a healthy lifestyle is recommendable but a connection between, for example, high blood pressure, food, smoking or drinking and HCHWA-D has never been established. Any factors that may have an effect on the development of the disease are still unknown.

How many people have HCHWA-D ?

HCHWA-D has been recorded in a number of families in the Netherlands but the number of carriers is as yet unknown. The Medical Centre of the University of Leiden, in collaboration with the Dutch CAA Foundation has recently rolled out a new research project to try and bring to light more information about this rare disease.

Research on HCHWA-D is also important because of the connection it shares with the (much more common) Alzheimer's disease.

HCHWA-D under the microscope.

Human chromosomes are made up of genetic material (DNA). The disease HCHWA -D is an abnormality of one of these chromosomes. 

The above-mentioned ‘abnormality’ causes an accumulation of proteins (amyloids) in the vessel walls of the brain, which in turn causes the blood vessels leading to the brain to become vulnerable and more susceptible to haemorrhages. Specifically, the smooth muscle cells are affected. This can lead to circulatory disorders in the brain- even before the first stroke. MRI scans can be used to detect these disorders.

The reason that an amyloid build up in blood vessels hardly occurs anywhere else in the body is as yet unknown.