Wake up at the back

Living with someone of the opposite sex, or getting married as it used to be known, is an interesting experience. One of the things you rapidly discover that your Mum never warned you about is that women are a distinct species.  You missed that revelation in your biology classes? Serves you right for snoozing on the back row but, as a recap of the evidence, consider the following. Species often show major differences in sensory perception – thus our cat is much better than I am at seeing in the dark, though he misses out a bit in daylight as cats don’t have colour vision. When it comes to hearing it’s a bit the other way round: most of the time you can shout at him til you’re hoarse with absolutely no effect – but one faint clink of a food bowl at the back door and, yet again, he’ll set a new Feline Fifty metres Steeplechase record from the front garden. And dogs, as is well known, hear frequencies way beyond what we can pick up.

Not in my lectures!!

The gentle sex has similarly evolved beyond what mere man can manage. Take colour, for example, at which men are, as we’ve noted, quite good – compared to cats. But, as you discover the first time you are taken ‘clothes shopping’ by your wife, other half, inamorata, partner, mistress or whatever, women have evolved far beyond merely spotting that blue is different from red and being able to recite Richard Of York (to remind themselves of the rainbow sequence). They see ‘combinations’ – so you are curtly informed that what has taken your fancy ‘just doesn’t go together’ in the sort of voice that adds ‘any nitwit can see that’ without the need to expend breath on the last seven syllables.

They’re at a similarly lofty level of evolution when it comes to sound. My lady wife avers that I snore – all the time (when asleep, that is) and very loudly. So much so that she tends to use a bed at the opposite end of the house for sleeping and only ventures within sonar range for other purposes. I’d always explained this behaviour as a manifestation of the amazing imagination possessed of the female that us boys are, of course, completely lacking. However, I’ve now come to appreciate that, like Fido (who sleeps in the kitchen), she simply has exquisitely sensitive aural apparatus. So maybe I do snore – but only very quietly or at ultra high frequency, so that I would be undetectable at rest to my own species and only my beloved and the dog would know what was going on (oh, and the cat because he can see the heaving chest).

Which is very reassuring since some fellows at the Universities of Wisconsin and Barcelona have got together to discover that snoring makes you nearly five times more likely to develop cancer. Strictly the problem is sleep disordered breathing (SDB) – which happens when there’s some kind of blockage of the upper airway and, apart from disrupting sleep, it can make you snore. Of course, there’s evidence that sleep disruption can contribute to all sorts of problems from heart disease to car crashes but this is the first study making a link to cancer.

No problem for me (discounting the wife’s super sonar) but should real, habitual snorers panic? Please don’t for most of the usual reservations to this type of study apply – relatively small numbers (1522) for example. The volunteers came from an alluringly named body of men and women called the Wisconsin Sleep Cohort, set up in 1988 for prospective studies of sleep disorders. In fact the interesting ones here are what we might call the Winsomniacs – the 365 of the Cohort who can’t do it rather than the majority of Badger State dreamers. Split in this case into sub-groups of SDB severity – the strongest association being with the most severe SDB. Although the authors did their best to allow for other factors (obesity – a common cause of SDB – diabetes, smoking, etc.) it’s almost impossible in this type of study to eliminate everything bar the one factor you’re focussing on.

The most frequent linked cancer was of the lung, followed by bowel, ovary, endometrial, brain, breast, bladder, and liver. And the cancer risk was up to four-fold greater for the worst afflicted.

Do the boffins have any helpful suggestions? Not really. Those unlucky enough to be severely affected can try a gadget called a continuous positive airway pressure device but, for the rest, console yourselves that the risk is small and the data so far are very preliminary. Put another way, you have more important things to think about – like finding a partner (preferably with sub-standard sonar detection capability) who loves you so much they’re willing to poke you in the ribs whenever you become aurally intrusive.

References

http://www.telegraph.co.uk/health/healthnews/9278214/Snoring-can-raise-cancer-risk-five-fold.html

Javier Nieto, F.J. et al. (2012). Sleep-disordered Breathing and Cancer Mortality: Results from the Wisconsin Sleep Cohort Study. American Journal of Respiratory and Critical Care Medicine 186, Iss. 2, pp 190–194.

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A Sinister Side to Sequencing

As a youngster I naturally imbibed everything I was taught about sex. By the time I emerged from the British university system this amounted to precisely two things: babies come from ladies and there is a really exciting moment just after one pops out when somebody says “It’s a boy!” or, as a variant, “Congratulations Mrs. Miggins, you have a lovely daughter!”

 

Many years and a career in science later, I now know a little more including the fact that out of every 100 babies born one will have an error in their genetic material that will give rise to a disease. There are more than 3,000 of these diseases, each caused by mutation of a single gene. For some only one of the two copies of a gene need be mutated: for others both copies must be abnormal for the disease to show itself, an example of the latter being cystic fibrosis that occurs in 1 in 2,000 of live births.

Many of these conditions are life threatening and those who have followed my recent eulogies about the wonders of DNA sequencing might have thought that a bit of its fire-power might be turned in their direction. Well, now it has been by a combination of several of the leading genetic disease groups in the USA. Their approach uses the fact that floating in the blood of pregnant women is a significant amount of DNA that has come from her developing baby. This can be easily isolated from a small blood sample (so the procedure is ‘non-invasive’). Repeated sequencing is then used to compare the entire DNA code from junior with that of both his Mum and Dad. This is essential to obtain the accuracy required for reliable detection of mutations carried by the fetus.

Hitherto it has been possible to detect conditions such as Down syndrome because that arises from a gross abnormality – an extra copy of an entire chromosome. However, this work means it is now feasible to do comprehensive, non-invasive, prenatal screening for all genetic disorders. The methods need to be refined and the cost lowered before this becomes generally available but you can be sure this will happen sooner rather than later. A by-product will, of course, be an accounting of X and Y chromosomes, but the suspense of that unknown has been long banished from delivery rooms with the coming ultrasound scans. It might also be noted that inherited mutations in major ‘cancer genes’ would also be picked up – though they contribute only about 10% of cancers.

Whilst this is yet another remarkable scientific advance that in due course will affect many lives, it comes with some serious strings attached. Knowing that an infant will be born with a given defect will mean that the best way of dealing with the condition can be planned in advance. However, it also means that parents may opt not to have afflicted children. This presents serious social and legal challenges that will be magnified if we begin to define genetic variants that associate with, say, intelligence, ball skills or whatever.

For neither the first nor the last time, the wonders of science present mankind with both riches and conundrums.

Reference

Kitzman, J.O., Snyder, M.W., Ventura, M., Lewis, A.P., Qiu, R., Simmons, L.E., Gammill, H.S., Rubens, C.E., Santillan, D.A., Murray, J.C., Tabor, H.K., Bamshad, M.J., Eichler, E.E. and Shendure, J. (2012). Noninvasive Whole-Genome Sequencing of a Human Fetus. Sci Transl Med 4, 137ra76 (2012); DOI: 10.1126/scitranslmed.3004323

http://www.nytimes.com/2012/06/07/health/tests-of-parents-are-used-to-map-genes-of-a-fetus.html?_r=1&pagewanted=all