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Charles on… anything that comes along

Tuesday 28 February 2006

Filed under: — Charles @ 11:42 pm

Strictly speaking, it’s Catch-26: of deafness, syndromes and DNA

baby3 had to go for a minor op the other day - to have grommets put in (because his middle ears seemed blocked). It takes general anaesthetic, so it’s just faintly scary. But we’d managed to get ourselves to feeling calm about it.

Then just before we signed the consent form, one of the doctors explained that they’d like also to take an ECG (electrocardiogram - monitoring the heart’s electrical activity) to, well, because, um, sometimes there can be heart problems associated with deafness. Very rare. But they’d like to know. To rule it out.

And were there higher risks in him having an anaesthetic if he did have this condition? Ah, well, yes, but they needed him to be asleep before they could take the ECG. We never expected to be bitten by Catch-22 in a hospital.

We felt more than a little blindsided by this. Couldn’t they have mentioned this quite some time ago? Yes, they could have. But what I realised after a little online digging is that there’s a huge amount that they haven’t been saying to us. There are all sorts of conditions that they think baby3 might have, but which they don’t want to mention to us. Charitably, one would say that it’s because they don’t want to worry us. Less charitably, one would say they don’t think we know how to handle the information.

See, when someone is born deaf for no apparent reason - no deafness in the family, not a premature birth (”prems” can suffer deafness because there’s insufficient time for ear organ development), not through infection of the mother during pregnancy - then it’s pretty surely a genetic cause. There are lots of potential causes of deafness; one of the most common is a flaw in connnexin-26 (”Cx26 has a carrier rate of 3%, similar to that for cystic fibrosis, and it causes about 20% of childhood deafness”. And more: the protein it makes is one of the main proteins involved in potassium homeostasis - that is, keeping the levels of potassium ions steady - in the cochlea’s supporting cells, fibrocytes of the spiral ligament and cells of the spiral limbus - hey, this all comes from a doctor who’s really called House!). But in many of them, you don’t get deafness on its own. You get a syndrome, a collection of symptoms that are all linked back to the misbehaving gene, or genes.

This is where it starts to get scary for a parent. You start Googling “deafness syndrome” and looking around and find things like this page about genetics and hearing loss which has such jolly entries as

Examples of associated abnormalities include vision loss due to retinal degeneration (Usher syndrome), enlarged thyroid (Pendred syndrome), and sudden fainting attacks caused by a heart defect (Jervell and Lange-Nielsen syndrome). Unlike WS, which is usually autosomal dominant, these three syndromes all show an autosomal recessive pattern of inheritance.

Autosomal recessive is the class of deafness that baby3 has. Seeing Usher syndrome gave me the experience that the cliche calls “chilled to the marrow”. It’s a cold start, a real glimpse of horror. The child is born deaf. Then in their teenage years, they go blind.

Fortunately - another bullet avoided - baby3 doesn’t fit Usher syndrome. He’s got good balance (he’s almost walking, a week from his first birthday); disturbed balance is a sign of Usher in infants with profound deafness. We’ll wait to hear about the heart defect (JLN syndrome; it’s indicated by a long QT cycle, which I amazed myself by having heard of before) and Pendred.

But seeing that page means it’s suddenly difficult just to see the deaf children of hearing parents only as “deaf”. Instead they suddenly seem like a timebomb that might be armed, that you can’t defuse because we can’t reach into our DNA; even if we could, we don’t even know which wires do what, which to cut, which to leave alone. I have the impression that every individual’s DNA is a complex of errors and mistakes, where the human within somehow stumbles through. None of us is genetically “clean”; it’s all relative.

Then in the children’s play centre the other day I saw some parents with a small(er) baby who noticeably had two hearing aids. Ah, fellow union members. I got talking. They said he had been diagnosed as severely to moderately deaf at about three months; not earlier, because he’d been in hospital for ages with hyperinsulinism - the opposite of diabetes, where the body produces too much insulin.

They were nice and the child was lovely. But having previously had the electric jolt of wondering whether baby3 might go blind some time in his teens through retinitis pigmentosa, I had a quick Google in a spare moment later: hyperinsulinism deafness syndrome yields rather a lot of Usher-related noise. Not definite. But suspicious. He was their first child. He might be blind by the time he’s 20, in which case all the effort teaching him to lip-read in primary school will be wasted. A charming couple with their first, lovely, child.

So tell me again about Intelligent Design. I already didn’t need to be persuaded that was a load of crap; the existence of parasitic wasps that paralyse their prey and lay eggs in them (so their young get to feast on the paralysed, living flesh) proves that if there were a God then he’d be a vicious bugger whom you’d never, ever want to meet. I’d rather have the randomness of evolution. But even there, the collateral damage inflicted on us by our aching, beaten-up DNA is sometimes more than we’d ever choose to bear.

One Response to “Strictly speaking, it’s Catch-26: of deafness, syndromes and DNA”

  1. Rupert Says:

    Nothing much useful to say about your child, except that with Google it’s no longer really up to the doctors to decide what to tell us. I’ll hope for the best, of course, because that’s all there is to be done from this end.

    But the more I read about genetics, biochemical pathways and like — an education I’m receiving mostly through paying attention in the sorry business of ID — the more it seems incredible that the stuff works at all, let alone well enough to create and sustain consciousness. There have been times when I’ve been overtaken with the conviction that such a jury-rigged, superlatively complex set of flaky chemical reactions cannot possibly work for five minutes more, let alone have got here through four billion years of continuous development. Quite, quite terrifying. The flip side is that if something so unimaginably baroque can be demonstrably so robust, it’ll have to be a dark day on Earth indeed to really mess things up for good.


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