 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Medical Forum / General / Vision / July 2007Heredity and Colorblindness
My maternal grandfather is colorblind, my mother is colorblind, I'm colorblind, but my brother is not. My father is also not colorblind. I don't know of anyone colorblind on my dad's side. One of my friends told me that in some science class they discussed heredity and found out that if your mom is colorblind you are definitely color-blind. But my brother is not color-blind. Is one of us adopted, or does that teacher need some more lessons themselves? Regards, Joe (from MN) > My maternal grandfather is colorblind, my mother is colorblind, I'm > colorblind, but my brother is not. My father is also not colorblind. [quoted text clipped - 6 lines] > Regards, > Joe (from MN) Ha! The funny thing is I had a biology lesson about this in school just yesterday. I think it has something to do with recessive and dominant genes; If your mother had the dominant gene, but your father had the recessive form, and you end up with the dominant form, then you will be colour blind. Likewise if you brother ended up with two pairs of the recessive form, then he wouldn't be colour blind. Well, I think that's how it works anyway! -KH On Jun 29, 12:33 pm, Kisame Hoshigaki <absolutelyinvinci...@hotmail.com> wrote: > > My maternal grandfather is colorblind, my mother is colorblind, I'm > > colorblind, but my brother is not. My father is also not colorblind. [quoted text clipped - 19 lines] > > -KH guess you didn't pay attention in class Revival (or Zetsu, or whatever the name-of-the-day is). colorblindness is X-linked. if a mother has it, then there is virtually no way one son can have it and the other son can't. do you understand the concept of sex-linked traits? do you know how many X chromosomes males and females have? do you know how many affected X chromosomes a color-blind woman has? i know, why not make up a different name and post tomorrow as a genetics expert who claims to know everything on this topic? yesterday you already posted twice under two different names to some guy who asked about the visual effects of prozac and you tried to act like you really were an expert on the subject. tell me, which do you like better in your internet forum role playing games-- the role of the naive 12 year old student, or the expert authoritative adult? did you ever play dolls as a child? has anyone ever suggested you get professional counseling? pclar, >guess you didn't pay attention in class Revival (or Zetsu, or whatever >the name-of-the-day is). [quoted text clipped - 3 lines] >chromosomes males and females have? do you know how many affected X >chromosomes a color-blind woman has? Yes admittedly, I wasn't really paying much attention in that lesson -- And yesterday was the first time I even heard about genes and alleles and so forth, so exc-*Use* me if I'm not suddenly an expert in that field! You don't have to go berserk, man. >tell me, which do you like better in your internet forum role playing >games-- the role of the naive 12 year old student, or the expert >authoritative adult? Actually I am 15 years old. >some guy who asked about the visual effects of prozac and you >tried to act like you really were an expert on the subject. No, I didn't. I just happened to know a little bit about the effects of Prozac -- I wasn't trying to act like an expert on the subject. Anyway, that's why I wrote 'but check with your eye doc' at the end. Jeeze! Thanks everyone for the postings, but I still don't seem to know the answer to this question. I'll ask my eye doctor (which was suggested by a 15-year-old and is probably the best answer here!) > Thanks everyone for the postings, but I still don't seem to know the > answer to this question. I'll ask my eye doctor (which was suggested > by a 15-year-old and is probably the best answer here!) I don't think he'll know whether you're adopted or not. There are too many varieties and degrees of "colorblindness" to draw that conclusion without lots more information. -MT On 7/2/07 7:31 AM, in article l4udnaZP58jHkRTbnZ2dnUVZ_ternZ2d@giganews.com, > I don't think he'll know whether you're adopted or not. There are too many > varieties and degrees of "colorblindness" to draw that conclusion without > lots more information. What are the most common, although probably rare, types of colorblindness that are not X linked? Even so, what kind of colorblindness of a mother could possibly not show up in a son? Bill -- Support the troops. Impeach Bush. Oh, I forgot about Cheney. > What are the most common, although probably rare, types of colorblindness > that are not X linked? Even so, what kind of colorblindness of a mother > could possibly not show up in a son? From the example, it could be autosomal dominant. If it's the typical XLR, there has to be another line of inheritance we don't know about. Also clouding the question are variable expression, incomplete penetrance, and mosaicism. I'm just not ready to say his brother is adopted. -MT On 7/2/07 12:09 PM, in article 9M6dnXUA9OXt0BTbnZ2dnUVZ_jqdnZ2d@giganews.com, "Mike Tyner" <mtyner@mindspring.com> wrote: > From the example, it could be autosomal dominant. If it's the typical XLR, > there has to be another line of inheritance we don't know about. Also > clouding the question are variable expression, incomplete penetrance, and > mosaicism. Are you saying that there are some dominant autosomes that will overcome ordinary color defective X chromosomes? That sounds mighty far fetched. Similarly, it is very difficult for me to believe that there would be a defective X mutation producing a mosaic X without the defect. My guess of a brother that is an XX with some defect in sexual development (excessive testosterone for example), far fetched as it is, is less far fetched than a mosaic mutation that corrects a gene defect. An adoptive brother seems the most likely possibility so far. A DNA test ought to establish kinship. Bill  SignatureIraq: About three Virginia Techs a month > Thanks everyone for the postings, but I still don't seem to know the > answer to this question. I'll ask my eye doctor (which was suggested > by a 15-year-old and is probably the best answer here!) hi Revival > My maternal grandfather is colorblind, my mother is colorblind, I'm > colorblind, but my brother is not. My father is also not colorblind. Most "colorblindness" is inherited as X-linked recessive, but there are several variations, and no reason two independent genetic problems can't exist in the same family. Yours may not be the typical x-linked recessive pattern. It isn't unusual for real-life bloodlines to deviate from the simple rules you learn at first. -MT > > My maternal grandfather is colorblind, my mother is colorblind, I'm > > colorblind, but my brother is not. My father is also not colorblind. [quoted text clipped - 8 lines] > > -MT Mike, is it possible to acquire colourblindness? My grandfather became colourblind recently, which he wasn't before. On Jun 29, 10:02 am, Kisame Hoshigaki <absolutelyinvinci...@hotmail.com> wrote: > > > My maternal grandfather is colorblind, my mother is colorblind, I'm > > > colorblind, but my brother is not. My father is also not colorblind. [quoted text clipped - 12 lines] > > My grandfather became colourblind recently, which he wasn't before. Mike, Please recall the sage words of this very same poster: [quote] Dear Mike, I don't understand: What does this squabbling accomplish? We have established that Otis refuses to answer valid questions: Yes. We have established that Otis refuses to leave this newsgroup: Yes. But why continue this same argument year after year after year? How does it benefit this newsgroup? [/quote] > On Jun 29, 10:02 am, Kisame Hoshigaki > [quoted text clipped - 34 lines] > How does it benefit this newsgroup? > [/quote] Mike seems like a wise man; all I did was ask him a question! > Mike, is it possible to acquire colourblindness? > > My grandfather became colourblind recently, which he wasn't before. It won't be the same as genetic colorblindness. In grandfathers, it's usually cataract that causes color distortion. In grandmothers, it causes them to dye their hair blue. -MT > > Mike, is it possible to acquire colourblindness? > [quoted text clipped - 7 lines] > > -MT Oh, I understand now. Thank you, Mike! In fact, my grandfather has perfectly normal vision, apart from the colourblindness -- so I guess he must have inherited it. -- >color I have always found it funny how Americans spell colour as color LOL. It's so confusing! Oh, I understand now. Thank you, Mike! In fact, my grandfather has perfectly normal vision, apart from the colourblindness -- so I guess he must have inherited it. Off-topic: I have always found it funny how Americans spell colour as color LOL. It's so confusing! -KH > Oh, I understand now. Thank you, Mike! > > In fact, my grandfather has perfectly normal vision, apart from the > colourblindness -- so I guess he must have inherited it. No. Ordinary colorblindness (the genetic kind) isn't acquired. It's there from birth or it isn't there. Your granddad got nuclear sclerosis. > Off-topic: I have always found it funny how Americans spell colour as > color LOL. It's so confusing! That was Daniel Webster. Don't worry. We'll understand if you want to include "u". -MT On 6/29/07 9:53 AM, in article sKKdnX-AMvixpBjbnZ2dnUVZ_tqnnZ2d@giganews.com, "Mike Tyner" <mtyner@mindspring.com> wrote: >> My maternal grandfather is colorblind, my mother is colorblind, I'm >> colorblind, but my brother is not. My father is also not colorblind. [quoted text clipped - 8 lines] > > -MT There is always the possibility of a new kind of colorblindness that is not carried on an X chromosome. Aside from the possibility suggested by the OP that his brother is adopted rather than biologically related, there is the far out chance that his brother has not developed properly from a YY genotype. If that is the case than his father would have contributed one Y which is dominant and normal. Bill -- Support the troops. Impeach Bush. Oh, I forgot about Cheney. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.