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A Gene Causing Dyslexia Found
Rovaani writes "A group of Finnish scientist have found a gene causing dyslexia. Dyslexia is the most common learning disorder among children and affects anywhere between 3 percent and 10 percent of the population."
But how can ageing cause dyslexia? I thought people had it when they were young?
Dyslexia is the most common learning disorder among children and affects anywhere between 3 percent and 10 percent of the population.
And in some cases, parents urge doctors to diagnose dyslexia so the child gets 'special' treatment (e.g. more time at exams) at school resulting in better grades...
Yes, I know, there are children that really suffer from dyslexia, and yes, there are doctors who refuse to give a false diagnosis. But sometimes I get the feeling that the percentage of kids suffering from dyslexia is somewhat higher than 10% -- or is this a local phenomenon or my misconception?
My cats ate my karma. They also wrote this comment.
I don't think you could be more wrong...unless you left out the bit about it being done in only one family.
Firstly, just because siblings sometimes share a problem doesn't prove that it's genetic. Siblings often share a bicycle, but that doesn't mean there's a gene for that. To really prove this sort of thing you need to look at twins who preferably have grown up apart. Researches are starting to realise that even this is not always enough. Changes in gene activation can be inherited without having anything to do with the genetic code. For example, lung size in tibetans takes several generations to return to normal after moving to lower altitude. It's thought that this is something to do with methelation of the chromosomes.
Secondly, finding a gene that causes a disease (even if there are others that remain undiscovered) does a LOT to combat the disease because you can start to target the cause. It's very little to do with proving that it's genetic rather than environmental.
Karma police, I've given all I can, it's not enough, I've given all I can, but we're still on the payroll.
1. In the first family, a gene called DYXC1 was disrupted. So if there is anything to this story, then the gene may help prevent dyslexia, rather than cause it.
2. "In a complex disorder, even a modest increase in genetic risk may be interesting," they wrote. "There is overwhelming evidence that dyslexia is a genetically complex condition." So if this is really a factor, then it is likely to one factor among many, rather than an accurate diagnostic tool.
3. To compare, the team studied 20 unrelated Finnish families, with 58 dyslexic and 61 non-dyslexic members. In the first family, a gene called DYXC1 was disrupted. In another, DYXC1 has a "stop sign" in the wrong place, which causes cells to produce a shortened version of the DYXC1 protein. So if DYXC1 is not a factor in the other 19 families, despite numberous dyslexic members, then it seems likely to be a small factor across the population.
Quite a long way from finding the sole cause of dyslexia, which is possibly the impression tomorrow's headlines will give. Dyslexia may turn out to be something that everyone has to a degree, and only those severely affected are diagnosed.