Is dementia hereditary?
The majority of dementias are not inherited, but this depends very much on the particular cause of dementia.
Many people with dementia are concerned that their disease may have been inherited and that they may pass it on to their children.
Family members of people with dementia are sometimes concerned that it might be more likely to develop dementia themselves.
The majority of dementia is not inherited, but this depends very much on the particular cause of dementia.
Some (rare) causes of dementia are very clearly 'inherited', for example, Huntington's disease. This is an 'autosomal dominant' disease which means that only one faulty copy of the gene is needed in order to inherit the disease. In the case of frontotemporal dementias, 30 to 50 per cent of cases are inherited.
If you have inherited the gene, you will get the disease if you live long enough. It does not skip a generation. Some other dementias have both inherited and non-inherited forms.
Is Alzheimer's disease inherited?
Many people fear that Alzheimer's disease in the family may be passed on to children and grandchildren. In the vast majority (99 per cent) of cases, this is not so.
Like many conditions, having Alzheimer's disease in the family does very slightly increase the chance of people in later generations getting the disease.
The most important risk factor for Alzheimer's disease is age. Because Alzheimer's disease is so common in people in their late 70s and 80s, having a parent or grandparent with Alzheimer's disease at this age does not change your risk compared to the rest of the population.
Understanding risk factors for dementia
Find out how different factors, such as age, genetics, lifestyle choices and health conditions, can affect your dementia risk with our free tool.
In a very small number of families, Alzheimer's disease is inherited. The impact of these genes was first discovered more than 100 years ago and accounts for less than one per cent of all cases of Alzheimer's disease.
For these families, this is a devastating legacy. The disease usually develops at a much earlier age than usual, with individuals being affected as early on as their 30s. Three genes have been identified as causing this early-onset inherited form of Alzheimer's disease.
Defects in these genes can now be tested, and if the particular gene is known, individuals may choose to have predictive testing. Predictive testing is always preceded by careful genetic counselling.
National Dementia Helpline
Is there ongoing research into inherited dementia?
Inherited dementias have provided great insights into the causes of different dementias, largely through members of affected families generously volunteering to participate in research studies. Research is very active in many different centres around the world.
In 2008, an international consortium called Dominantly Inherited Alzheimer Network (DIAN) was set up to study familial Alzheimer's disease to try and understand more about the causes and earliest features of this devastating condition.
Take part in dementia research
Join Dementia Research is a UK-based service that allows people to register their interest in taking part in dementia research.