Monday, 23 September 2013

The gene genie (Part 1)

When it comes to genetics, there really is nowhere to hide. Your genes speak more eloquently about you than a Times obituary. Everything that makes you you and me me (sorry, this sounds like a giant panda mating) is encoded in our genes. They can even make educated guesses on how we live and die.

As my regular readers know, I have had Parkinson's for the last seven years. I was diagnosed at the age of 49 which, although not in any way unique, is still a relatively young age. Young enough that you might reasonably suspect some predisposing factor to be at play. Such as genetics for instance.

Over the last decade or so, we've learnt a lot about genetic involvement in Parkinson's. Although the overwhelming majority of cases are classed as idiopathic, a fancy word meaning that we don't know the exact cause, a small proportion are less enigmatic. In a small proportion of cases, there is one or more genetic risk factors.

Current thinking, and I won't bore you with the scientific details here, suggests that there is somewhere in the region of 15 separate genes where mutations will increase the risk of developing Parkinson's or speed its progression. In the worst cases, mutant genes can treble the odds of developing Parkinson's. The resulting conditions are, in essence, forms of genetic Parkinson's. As I said, these subtypes are rare, affecting only the small proportion of people. But this proportion of genetic Parkinson's is higher among the young onset group of.

Now I don't delude myself for one second that forty nine is young or in any way in the first flush of youth. But it still, if I'm honest, rankles that I should have got Parkinson's ahead of the crowd. Let's face it -- this is not a queue that anyone wants to jump. So, at the back of my mind is the thought that there might be some genetic component to my Parkinson's.

Maybe, I reason, I have one of the genetic forms. The odds are against it but it is the least possible.

Does it matter? Well, in the grand scheme of things and if I was the only person concerned, it probably doesn't. You shrug your shoulders and get back to the Times crossword.

But it isn't just me. Genetics in this context touches two important aspects of life -- the genes that we receive from our parents, and the genes we pass on to our children. And to put the thing in a nutshell, my biggest worry is not whether I have a genetic form of Parkinson's. It's the kids.

When I 'came out' about my Parkinson's, all the children separately asked two questions:

"Are you going to die?"

"Will I get it?"

The first one is easy, maybe too easy. No, the Parkinson's will shorten my lifespan a little and certainly make it rather more challenging, but it will not kill me directly, at least not over the kind of timeframe they feared.

The second question is harder to answer and, in the absence of any definitive reply, I trotted out the old statistics -- that fewer than one in 10 have a genetic form of Parkinson's and therefore a form that can be inherited. In other words, it was highly unlikely that they would 'catch' Parkinson's from me.

For a long time that seemed a satisfactory response. Either the children were satisfied or wanted to be satisfied. Or reassured. And in 2006, that seemed a reasonable position to take.

But that's the problem with truth -- it's an absolute. Truth doesn't deal in probabilities. At the end of the day 'highly unlikely' is not the same as 'definitely not'.

And truth gnaws.

What starts out as a vague feeling that it would be nice to know one way or the other becomes, in the fullness of time, an overwhelming need to be certain. A need to find unequivocal reassurance or to know with certainty how deep is the abyss.

I've always believed in serendipity. And I was thinking on the subject of genetic testing a couple of months ago when I stumbled across an ad for 23andme. As many know, they offer a service, for a price, that will tease your genome apart and look for these dodgy genes, in amongst the other genetic dross of course.

The service comes to around £100 per genome, the price of three quarters of a tank of petrol for the Jag, a week's shopping or maybe a dozen CDs. So, in relation to the amount of information to be gathered, a trifling sum. And such is the speed of progress in this field of science that projects to sequence the entire human genome, initiated in 1990, were projected to take around 15 years and cost about as much in real terms as putting a man on the moon. It tied up huge research laboratories and occupied some of the finest minds in science for a decade. It was Big Science.

Now, a little over a decade after the sequence was announced, the technology exists to offer it as a simple test, in the same way you would test blood cholesterol for instance. Even as little as five years ago this would have necessitated a second mortgage. The speed of progress is breathtaking. And at the risk of sounding like a commercial, it's piffly easy. The company sends a plastic container, you spit in it, seal it and send it back to them. 4 to 6 weeks later, you get an e-mail saying your results are available online. And you also receive a much longer preparatory explanation to the effect that this is big league stuff. You might not like the answers provided by your genes. It's a case of 'open at your own peril'. And bearing in mind that we are potentially looking at life changing illnesses, the caveat is probably necessarily sobering.

There is no counselling offered. Nothing to sweeten the pill if necessary. You are very much on your own. They say as much.

My e-mail arrived three weeks ago. I read the disclaimer and thought for a second or two whether to login or not. What would the report show? Was I even remotely prepared?

In any case, you can never get the genie back in the bottle.

I took a gulp of coffee and clicked the link.

[Check into the next blog to read about the results].

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