Yesterday was Rare Disease Day, although I missed the opportunity to write about it here. It does happen every year, in spite of it being on Leap Day this time.

But the report today that linked the Zika virus to an increased risk of developing Guillain-Barré syndrome has brought rare diseases back into the limelight. Rare diseases and disorders are defined as those which affect fewer than 1 in 2000 people, and there are over 6000 conditions that qualify.

And, counter-intuitively, a lot of people do suffer from rare diseases, just because there are so many of them. It is estimated that 3.5 million people in the UK have a rare disease, and half of them are children.

Eric Avebury was a great champion of rare diseases, and I enjoyed some stimulating email conversations with him about it after he wrote this post. He suffered, and eventually died from, a rare form of leukemia, which must have sparked his interest in rare diseases, although he was such a wonderful campaigner for all sorts of minority issues, from caste to gay asylum seekers.

Having a rare disease delivers a quadruple whammy. First, diagnosis takes a while because GPs will probably not have seen it before, and even specialists may only have seen one or two cases in the past. Second, rare diseases tend to be more complex than common diseases, and present in a variety of ways, which makes diagnosis difficult.  Third, because so few people suffer from any given rare disease there is, at most, only limited research – and then with a sample that is sometimes too small to yield useful results. As a result treatment may be a bit hit-and-miss and verge on the experimental. And finally, if drugs have been developed specifically for a rare condition then they are likely to be very expensive; sometimes patients and their families have to fight NHS bureaucracy to get them.

Last summer Greg Mulholland held a Westminster Hall debate on the provision of drugs for ultra-rare diseases after constituents explained to him how difficult it was for them to obtain treatment for their son.

My personal story is this. Some 25 years ago my husband was diagnosed with Guillain-Barré syndrome, which attacks the nervous system. It is pretty rare and affects only around 1200 people in the UK.  He was treated with infusions of immunoglobulin which halted the progression of the disease, but it was six months before he was well enough to go back to work. In otherwise healthy patients Guillain-Barré syndrome has a good long term prognosis, but it often leaves them with some weaknesses.

Then 5 years ago he developed the rarer chronic version of the syndrome, which means he has to have regular infusions, which are quite expensive, probably for the rest of his life, to keep him stable. And just last year he discovered that he had an even rarer variant, which has been found in around 30 people in the UK. He is getting excellent health care, but even so only one medical paper has been published on his variant, so not enough is known about it. He has had to decide whether to take a powerful drug which will have unpleasant side effects and which may, just may, improve his condition, or whether to stay on the infusions which do at least prevent it getting worse. The consultant has recommended the latter. Fortunately he has not had to fight to get the drugs he needs, although initially the local NHS watchdogs did need some persuading.

I do hope as a party we can keep up the initiatives pioneered by Eric Avebury and Greg Mulholland.

* Mary Reid is a contributing editor on Lib Dem Voice. She was a councillor in Kingston upon Thames, where she is still very active with the local party, and is the Hon President of Kingston Lib Dems.