How is ataxia considered to be rare when there are (I think) over 100 different types?

[Nigel-2112]

I think that it is not how many types but the occurance, so for FA it is around 1-3 per 100,000 or 10 - 30 per million, so over the UK popultion of 66 million that means a total of around 2,000 or 0.003%

[HarryB Administrator]

Ataxia is an 'umbrella term' for lots of different diseases. Although it is debatable whether ataxia itself is a rare disease, all the different causes of inherited ataxia (there are over 100 genes known to cause ataxia) are rare diseases in their own right. The definition of a rare disease is one that affects no more than 5 per 100000 people in the general population.

Taking FA as an example, this is only one cause of ataxia and is also the commonest inherited form of ataxia. Its prevalence is about 1 in 500000. The population of the UK is around 62 000 000. Using these figures there are 2 people in 100000 people in the UK who have FA. This makes FA a rare disease. As FA is the commonest inherited form of ataxia it can be assumed that other inherited causes are rarer.

As Ataxia UK supports everyone and anyone affected by ataxia, whatever the cause, it could be said that Ataxia UK actually supports over 100 separate rare diseases.

[Hidden]

Thank you both for your replys. I understand much clearer now as to how ataxia is considered to be a rare disease. I feel a bit dumb for thinking ataxia as being one condition. However, the info you have provided above may be useful to others. Thanks again.