View previous topic | View next topic

Dyslexia

Page 3 of 5
Goto page Previous  1, 2, 3, 4, 5  Next

Jenny
49861.  Wed Feb 08, 2006 7:46 pm Reply with quote

According to the books I've read about it Celebaelin, it's more common in boys than girls, but that's true of dyslexia too I think.

 
Celebaelin
49863.  Wed Feb 08, 2006 7:55 pm Reply with quote

I've read that of dyslexia (and doubted it 'cos...aaaaaanyway) but I've not found anything about dyspraxia and sex-linkage etc.

 
Tas
49910.  Thu Feb 09, 2006 6:51 am Reply with quote

Quote:
According to the books I've read about it Celebaelin, it's more common in boys than girls, but that's true of dyslexia too I think.


I wonder if that works in the same way as the sex-link to colour blindness, then?

*Just a random thought from a random mind*

:-)

Tas

 
Celebaelin
49921.  Thu Feb 09, 2006 7:18 am Reply with quote

Not wanting to be too blunt but no, it doesn't. If it did then female dyslexics/dyspraxic could only arise if both parents were dyslexic/dyspraxic. There might be a sex-linked contribution but it's not, can't be, the whole story.

 
Gray
49936.  Thu Feb 09, 2006 8:16 am Reply with quote

Girls concentrate and learn things a lot more effectively than boys. This is true even of chimpanzees.

 
Tas
49960.  Thu Feb 09, 2006 10:13 am Reply with quote

Quote:
Not wanting to be too blunt but no, it doesn't. If it did then female dyslexics/dyspraxic could only arise if both parents were dyslexic/dyspraxic. There might be a sex-linked contribution but it's not, can't be, the whole story.


I was not aware that colour-blindness was heriditary. Neither of my parents nor as far as we are aware any of grandparents were, and yet both my brother and I are.

I thought that colour-blindness was more prevalent in males due to the brain being unable to diferentiate between colours, and it was hypothesised that this was linked to the hunter ability from pre-history.

:-)

Tas

 
Jenny
50028.  Thu Feb 09, 2006 1:24 pm Reply with quote

I think some of the styles of teaching and learning that are adopted nowadays tend to favour the strengths of girls more, too.

 
Kevino7
50030.  Thu Feb 09, 2006 1:32 pm Reply with quote

Tas wrote:


I thought that colour-blindness was more prevalent in males due to the brain being unable to diferentiate between colours, and it was hypothesised that this was linked to the hunter ability from pre-history.

:-)

Tas

Females also have an extra cone in their eyes to distinguish colours.

 
DELETED
50037.  Thu Feb 09, 2006 2:05 pm Reply with quote

DELETED

 
Anachronism
50127.  Fri Feb 10, 2006 4:17 am Reply with quote

Pedantic Spice wrote:
I had to be assessed outside school as no-one realised there was a problem.


Oh, I wasn't assessed at school. I go to a grammer school, any type of learning difficulty is practically taboo here!

 
Celebaelin
50129.  Fri Feb 10, 2006 4:45 am Reply with quote

Tas wrote:
I was not aware that colour-blindness was heriditary. Neither of my parents nor as far as we are aware any of grandparents were, and yet both my brother and I are.

I thought that colour-blindness was more prevalent in males due to the brain being unable to diferentiate between colours, and it was hypothesised that this was linked to the hunter ability from pre-history.

:-)

Tas

There are different sorts of colour-blindness but the one that's talked about most is a sex-linked recessive trait. The affected gene is carried on the X chromosome and since females get one X from their mother and one from their father then for them to carry two copies of the 'colour blind' gene then the father would have to be colour blind and the mother would have to be at least a carrier.

Lets use Xc as the symbol for an X chromosome with the mutation so a colour blind male is XcY (rather than boring old XY for non colour blind males). Colour blind females have to be XcXc female carriers are XcX and normal females are XX. There can be no male carriers as males only have one X chromosome; they're either affected or their not.

(I've just realised that I was wrong in an earlier post about both parents having to be affected for a female to be affected - apologies if anyone believed me earlier, it was an error on my part)

The chances of both you and you brother being colour-blind when your mother is not (but is a carrier) are one in four. The father is irrelevant to this discussion as far as male offspring are concerned as he provides the Y chromosome in that instance. I didn't intend this to sound personal but it's unavoidable when talking about a condition which you do, in fact, have.

Seeing an old friend tonight who is, by co-incidence, red-green colour-blind. We were walking through Brum one time and I asked him if he could see a gate in the iron fence on the other side of the road. He told me that he could just make it out as a different shade to the rest - it was painted red and the rest of it was green. It's surprising how often this method of making things "contrast" is used, presumably unthinkingly. I handed him my house keys so he could let himself in just the other week not considering at the time that one has a green tab and one red. Doh!


Last edited by Celebaelin on Fri Feb 10, 2006 5:08 am; edited 1 time in total

 
Gray
50132.  Fri Feb 10, 2006 5:01 am Reply with quote

Briefly returning to colour blindness - there are various genetic conditions for having it (as opposed to acquiring it non-genetically). These are well covered here:

http://en.wikipedia.org/wiki/Color_blindness#Classification_of_color_deficiencies

Basically, they result from a mutation in one or more of the genes that code for the effectiveness of one or more of the colour receptors in our eyes.
Quote:
Genetic red-green color blindness affects men much more often than women, because the genes for the red and green color receptors are located on the X chromosome, of which men have only one and women have two. Such a trait is called sex-linked.

Genetic females (46, XX) are red-green color blind only if both their X chromosomes are defective with a similar deficiency, whereas genetic males (46, XY) are color blind if their only X chromosome is defective.

 
Gray
50133.  Fri Feb 10, 2006 5:02 am Reply with quote

Hah - Celebaelin beat me to it! :-D

 
Tas
50151.  Fri Feb 10, 2006 6:50 am Reply with quote

Quote:
Genetic red-green color blindness affects men much more often than women, because the genes for the red and green color receptors are located on the X chromosome, of which men have only one and women have two. Such a trait is called sex-linked.

Genetic females (46, XX) are red-green color blind only if both their X chromosomes are defective with a similar deficiency, whereas genetic males (46, XY) are color blind if their only X chromosome is defective.


I wonder causes my green-brown and blue-purple problems then...

:-)

Tas

 
Jenny
50247.  Fri Feb 10, 2006 11:02 am Reply with quote

Celebaelin - you're not the only one to be 'blind' (doh!) to the consequences of colour blindness in others. My first husband was slightly red-green colour blind, and when he was doing A level Chemistry he had to do a titration which involved a colour change that was very subtle and he just couldn't see. Of course in the sixties nobody made a fuss about things like that...

 

Page 3 of 5
Goto page Previous  1, 2, 3, 4, 5  Next

All times are GMT - 5 Hours


Display posts from previous:   

Search Search Forums

Powered by phpBB © 2001, 2002 phpBB Group