To know or not to know, the genetic factors of dementia

IMMEDIATE RELEASE
To: News/Health/Community Editors

Alzheimer Scotland has launched new information explaining the present knowledge about inherited risks of dementia. The leaflet is aimed at people who have a diagnosis of dementia, and close relatives who may be concerned about inheriting it.

Kate Fearnley, Policy Director for Alzheimer Scotland says, “A lot of people worry about dementia getting passed on down the family, and there is often confusion about the whether dementia is inherited. In fact, most cases of the illness are not inherited. The illness is so common that even having two close relatives is not evidence of a family link, although there are some rare forms of dementia which are caused by genetic faults. With most cases of dementia, your genetic make up may affect your risk of developing dementia in later life, but so do lots of other things, such as your environment and lifestyle. Having a close family member with the condition only increases your risk by a small amount.”

Familial early onset Alzheimer’s disease is caused by a faulty gene and is very rare. . A number of genes have now been identified that affect some families worldwide and cause early onset Alzheimer's disease, starting when the person is under 65 and sometimes affecting people as early as their 40s or 50s. On average, half the children of someone with one of these rare faulty genes will develop the illness. However it is important to be aware that most cases of early onset dementia are not inherited in this way.

The best known genetic risk factor for late onset Alzheimer's disease is a gene called Apolipoprotein (ApoE), which comes in three forms, one of which seems to increase the risk of developing Alzheimer's disease, but does not make it certain. Testing for this gene is not useful, as it does not predict whether someone will get the disease, and there is no special treatment for anyone who has the gene.

Kate Fearnley continues, “Anyone who would like to know more about genetics and dementia can call the 24 hour Dementia Helpline on 0808 808 3000 for an information sheet and a chance to talk over their concerns, or find it on our website, www.alzscot.org”

Contact details:

Sarah Bromley, PR & Marketing Manager, tel 0131 243 1453, mob 07904 624 696, sbromley@alzscot.org
Kate Fearnley, Policy Director, tel 0131 243 1453, kfearnley@alzscot.org

Notes to Editor:

The form of the ApoE gene which increases Alzheimer's disease risk is ApoE4, while ApoE2 seems to reduce the risk.

Some scientists think that ApoE4 does not affect whether a person will develop Alzheimer's disease but when, causing people with ApoE4 to develop the disease before people with ApoE2. As Alzheimer's disease is more common in older people, a later onset may mean someone does not develop the disease before their death.
Testing for the ApoE4 gene does not accurately predict whether people will develop dementia and is not available to patients and families.

Other forms of dementia are inherited such as Picks disease and fronto-temporal dementia. These are caused by genetic changes on the TAU gene but are very rare.

Pros and cons of testing for familial early onset dementia:

• Identify people who might benefit from drugs
• Help people plan for the future
• Help researchers to understand dementia better which may lead to improved treatment
• May incur problems with life insurance and mortgage in the future
• Causes increased anxiety without offering treatment

Dementia Facts

Dementia affects approximately 64,000 people in Scotland.
Alzheimer’s disease is the main form of dementia. The second most common is vascular dementia. As yet there is no cure.

Alzheimer Scotland is Scotland’s foremost voluntary organisation working for people with dementia and their carers. It:

• speaks out for the rights and concerns of people with dementia and their carers;
• operates services on over 60 sites throughout Scotland providing practical Services such as day, evening and weekend centres, home care and befriending and carers' support services;
• provides the 24 hour national freephone Dementia Helpline (0808 808 3000);
• provides the website www.alzscot.org;
• supports a network of over 40 carers' support groups;
• provides information to carers, professionals and people with dementia;
• publishes leaflets, booklets, reports and a quarterly newsletter keeping carers and professionals up-to-date
• has a research programme.