Monday, 25 April 2011

Increasing parental age and autism

I am trying to pitch at two proverbial birds with this stone of an entry. The title is quite ambiguous on purpose in that I am discussing both the suggestion of a link between advancing parental age at conception and 'risk of autism' but also the very important issue of aging parents and the provision of care for their children with autism. We will see how successfully this dual task is accomplished.

Reading through the research literature of 'risk factors' for autism, one thing outside of the sex ratio thing seems to crop up time and time again - how old parents were at the time of conception. In these times of more people having children later in life (the owness, rightly or wrongly, seemingly falling more on women than men), there is quite a lot of interest in what effects this may or may not be having on children born under such circumstances.

Whether it is mum's age or dad's age, several pieces of research have indicated a role of advancing parental years and later health and developmental outcomes. This quite large study for example, suggested that children of older dads did slightly worse on various cognitive measures compared to younger dads. Indeed, father's age has been the most interesting area when it comes to risk and conditions like autism - dare I say very strong evidence that crosses different populations?

At this point I think we have to be quite careful and remember my mantra about probability (not absolutes) and science. Yes, the results confirm a strong trend; but this by no means implies that every man in his late 40's+ fathering a child is 'predestining' that child towards autism. There are lots of other factors to consider, not least genetic influences, environment, etc; lest we start going back to the parental blame-game of times gone by.

The proposed mechanism for older dads and autism? Well there are several theories, many of which are explored on this blogsite, including methylation of DNA (something covered in my previous post on MTHFR), point mutations (SNPs), environmental factors, etc. It may be that other 'knock-on' factors such as low birth weight also come into play. Interestingly also, the calculations on what contribution older dads (and mums) have had to the rise in autism prevalence (at least in California) is not estimated to be massive. The bottom line: being an older dad carries a statistically significant association with childhood autism but lots of other factors are also potentially involved.

So then to the issue of aging parents and provisions of care for their children. This is a real issue and in years to come will, no doubt, become even more of an issue. Many parents have asked quite publicly 'what will happen to my child when I am old or when I am gone'?

Whilst appreciating that autism is a spectrum and that there are different types of presentation and different ability patterns within that spectrum, the issues of 'concern' and 'care' is pretty much a universal one given that even those at the high-functioning end of the spectrum have parents who still want to ensure the best for their child.

Many parents have blogged about this - one example is here. I read this entry and found it raised several important issues. Questions about a role for siblings in 'taking the reins'; questions about a role for 'social care'; and a very uncomfortable question about mortality. Although not by any means the same thing, similar questions have been asked about lots of other conditions not generally affecting life duration. There are no easy answers to this issue.

Assuming that there are siblings, one might expect them to take some "responsibility" if required, may be even assuming some kind of guardianship role where informed consent may not be easily given by a person with autism for example. Siblings are in a unique position because not only do they get an up-close look at autism, they follow the growth of their brother/sister and hence know more about them as a consequence.

The added benefit also being that siblings will have the best interests of their brother/sister at heart from a personal perspective rather than a social or financial ("what can the State afford") perspective. As this scenario becomes more of a reality, I expect to see many more brothers and sisters of people with autism becoming more vocal about such issues.

Some parents have talked about drawing up a personal plan of care of their child. Others have discussed drawing up wills and planning for the financial future of their child (which itself can have implications for benefits, etc). Planning seems all important to ensure that parental wishes are at least indicated.