Annual Review of Genetics
Posted online as a Review In Advance on 22 April 2003.
Genetics of Hair and Skin Color
Jonathan L. Rees
Abstract Differences in skin and hair color are principally genetically determined and are due to variation in the amount, type, and packaging of melanin polymers produced by melanocytes secreted into keratinocytes. Pigmentary phenotype is genetically complex and at a physiological level complicated. Genes determining a number of rare Mendelian disorders of pigmentation such as albinism have been identified, but only one gene, the melanocortin 1 receptor (MCR1), has so far been identified to explain variation in the normal population such as that leading to red hair, freckling, and sun-sensitivity. Genotype-phenotype relations of the MC1R are reviewed, as well as methods to improve the phenotypic assessment of human pigmentary status. It is argued that given advances in model systems, increases in technical facility, and the lower cost of genotype assessment, the lack of standardized phenotype assessment is now a major limit on advance.
Posted by Dienekes at October 3, 2003 10:15 PM | PermaLinkA question.
How far are we from (White -- caucasian) parents being able to "engineer" their offspring in terms of hair and eye pigmentation?
For e.g., we have a White couple who would like for their prospective child to have a specific phenotype: light skin, brow hair and blue eyes (I don't know...whatever). While using the genetic material of the parents in question.
Could something like this be feasable, i.e., designer babies, etc. (I mean is the technology far way into the future or just around the corner?)
For e.g., my aunt was very upset when my little cousin's eyes turned hazel (from light blue -- just like hers) -- I'm sure that if she could have decided on the matter, she would have liked for my cousin to have her eye colour. It was a big deal for her. My cousin is blond and has hazel eyes -- almost everyone else in my immediate family is blond and blue-eyed, so he kind of sticks out.
Posted by: friedrich braun at October 4, 2003 07:38 PMDNAPrint Genomics apparently is trying to patent a procedure that genetically determines eye color with high probability. This may be the first step to genetically engineering eye color. Of course things are not likely to be simple since eye color correlates with psychological variables.
Thank you for the info.
When you say that eye colour "correlates with psychological variables" what do you mean?
It's quite common for eye colour to change in White children.
Posted by: friedrich braun at October 4, 2003 10:33 PMSearch for "eye color" there's a bunch of studies in the blog.
Posted by: Dienekes at October 4, 2003 10:48 PMhope this doesn't sound too snarky dienekes-but f.b., contacts would go a long way wouldn't it?
Posted by: razib at October 5, 2003 01:21 AMIf we would discuss about the possibilities of genetic engineering, I would say there are much more important things than that. (what does not have to mean that this is totally unimportant to many people)
At the moment I would just be happier if more parents would look that there childrem are absolutely desease-free from the genetical point of view.
But especially in the German-speaking countries even this is disputed.
Dienekes:
I think Razib should be banned.
Regards,
Friedrich
Posted by: friedrich braun at October 5, 2003 11:43 AM>> I think Razib should be banned.
Thanks for the suggestion, but I keep my own counsel on who is to be banned.
Posted by: Dienekes at October 5, 2003 02:59 PMI was obviously kidding!
Posted by: Friedrich Braun at October 5, 2003 03:29 PM"MadScienceType" has a good answer:
You can do all that now, it would just be horribly expensive, not to mention the ethics of what happens to all the zygotes you don't want.
Certainly eye color, hair color and markers for various genetic diseases can all be selected for. You can do fun things with immune system markers, too. I'd be interested in finding out what genes are responsible for cancer development. I'm not sure about genes for intelligence or musical ability, though. The intelligence gene is an interesting concept, but work on it is probably not being done openly, for the obvious PC reasons.
It is possible to take a random zygote and introduce the genes you want, but it's a very iffy proposition that the genes you want will "take" and be expressed. Also, your offspring might be a chimera, in that some cells will express the desired gene(s) and some won't. Your hope there would be that the gene would be passed through gametes to the following generation, so if you want to engineer some grandkids, better start planning now!
http://forums.originaldissent.com/showthread.php?t=10260
Posted by: Friedrich Braun at October 5, 2003 07:01 PMChris, I don't understand what you say in your post. What is disputed in German-speaking countries?
Posted by: Unadorned at October 5, 2003 09:30 PMTo allow testing for genetical diseases and the possible abortion at a time after the 3rd months if the parents want so.
F.e., if you do in vitro fertilization in Germany its not allowed to select specific zygots even if you can think that the child could be suffering from a serious genetical disease.
This is totally absurd to me and has no justification.
That would like to build a house with all you need for it, with all the investment, but you know the plan for the house is wrong. This house will never be stabile or be able to house people.
The logical way would be to erase the old plan and to make a new plan for the house, and to use the material and energy to build a better one.
But not to use praenatal diagnostic is like building a house after a wrong plan which will never work, and will just take the place of a better and more useful house.
Praenatal humans are nothing else than such a plan, they are no human personalities.
Posted by: Chris at October 6, 2003 11:17 AM...the possible abortion at a time after the 3rd months if the parents want so = I meant if the foedus has a clear defect, not if the foedus has brown and not blond hair etc.
Is it possible for white parents to have a dark-skinned (olive) baby if the mothers great great grandmother was a very dark native american?
Posted by: Beverly Rush at June 14, 2004 11:27 AMI am trying to get some information on how to determine if my partner and I would have a redheaded child. I have a basic red hair color (not bright or nearly brown) and he has light brown, blonde if he gets out in the sun... I hope that you can help. Thanks!
Posted by: Ashley at July 15, 2004 08:37 AM