Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum left-handedness gene

An article in molecular psychiatry titled "LRRTM1 on chromosome 2p12 is a maternally suppressed gene that is associated paternally with handedness and schizophrenia". The full article seems only available to subscribers but there is a summary here:

http://anthropology.net/2007/08/01/lrrtm1-a-possible-gene-for-left-handedness/

From this site:

"LRRTM1 is not essential for left-handedness, but it can be a strong contributing factor."

Seems it's not only left-handedness it causes. The gene also has a "possible link to schizophrenia".

From the abstract at this site:

http://www.nature.com/mp/journal/vaop/ncurrent/abs/4002053a.html

"We found significant association of a haplotype upstream of the gene LRRTM1 (Leucine-rich repeat transmembrane neuronal 1) with a quantitative measure of human handedness in a set of dyslexic siblings, when the haplotype was inherited paternally (P=0.00002). While we were unable to find this effect in an epidemiological set of twin-based sibships, we did find that the same haplotype is overtransmitted paternally to individuals with schizophrenia/schizoaffective disorder in a study of 1002 affected families (P=0.0014). We then found direct confirmatory evidence that LRRTM1 is an imprinted gene in humans that shows a variable pattern of maternal downregulation."

I wonder if this gene has anything to do with ambidextrity.

That would be interesting wouldn't it. The same gene might be involved. As a guitar teacher I am aware there is a gradation of handedness. Some people are strongly one or the other but many are relatively comfortable either way, usually with a preference though.

My husband is strongly left handed and my oldest kid is comfortable either way though he writes right handed. He plays guitar very well and types about 136/wpm.

I'm ambidextrous; equally clumsy with both hands. I make lots of mistakes when I type, and have to look at what I'm typing from time to time. I type equally poorly with both hands. I'm very good at tying knots. In fact I helped my son learn to tie knots for Scouts. He said I was a better teacher than the scout master. I sign my name lefthanded, but I can write with my right, just not as well. Less practice. I have adapted to a right side mouse pad, but prefer to use left handed. I broke my left wrist recently and came to understand just how dependent I am on both hands. You never know what you use until you lose it. I'm glad it's temporary. :-)

Amaranth, I think you are onto something here, "Less practice."
I think ambidexterity would be more common if encouraged in children. When I was a child parents tended to push their child into using their right hand if there was any hint of left-handedness.

Well then you have to wonder about people like my brother-in-law who was born with only one arm. Would he have been right handed naturally or a lefty like his brother?

Scpg02. Did your brother-in-law take up paperhanging by any chance?

No comment re-paperhanging.

Left-handedness is an interesting phenomena. Supposedly due to the right hand side of the brain exercising more control than the left?

Prior to 40 years ago, Children who wanted to write with their left hand, were encouraged/forced to use their right hand.
But not today, since some children developed a stutter/or were slower learners.
True lefthanders can be spotted early in life with the following signs.
Drawing with the left hand, kicking a football with the left foot. Throwing, using the left arm .Possibly peering thru a kaleidoscope/telescope/microscope with the dominant eye, might be a pointer?

Its an interesting fact that the ancient Isralites built up a large army, entirely composed of left-handed men, who seemed to excel in warfare.
The Book of Judges contains the record of 700 men in the Tribe of Benjamin, all left-handed.
Judges 20:16...states that "everyone could sling stones highly accurately, and not miss" The left-handed marksmen in the Tribe of Benjamin rarely if ever fell short of their target.

I think its probable, even today, that a "lefty wrestler or boxer, could have a slight advantage? Since the average right handed sportsman only gets to train against similar right handed persons.
So I suppose when coming up against a left-hander for the first time, they might well feel disadvantaged?

My only claim to being lefthanded is my writing, kicking and throwing.
In everything else, I seem "normal"? (No jokes please)
I have noticed that if I ever went to the cinema with a girl, I prefered her to sit on my right side!
Anyone else have that perculiarity?

Mike: "I have noticed that if I ever went to the cinema with a girl, I prefered her to sit on my right side!"

Which suggests that ambidextrous men prefer to have a girl on each side?

LOL. Top of the class for that one Rede.

Mike Kremer