What is color vision deficiency and how is it inherited?
Approximately 8% of men and 0.4% of women have a color vision deficiency which is commonly referred to as “color blindness”. In the most common type individuals have a hard time distinguishing between certain shades of red and green. Color vision deficiency is most often inherited as an X-linked trait. X-linked inheritance means that the gene causing this condition is located on the X chromosome. Women have two X chromosomes. If a woman inherits an X chromosome with a gene that does not work properly, she usually has a working copy on her other X chromosome and will have normal color vision. However, men have one X chromosome and one Y chromosome. The Y chromosome does not carry the same genes as the X chromosome, so men only have one copy of the gene that is responsible for color vision. Therefore, if a man inherits an X chromosome that is not working, the man would not have a back-up copy and will have a color vision deficiency. A donor who has color vision deficiency passes his Y ch
About 8-10% of all men have difficulty distinguishing between certain colors. This does not mean that affected individuals see only black and white, or that colors are invisible to them. In the most common type of color vision deficiency, commonly known as color blindness, individuals have a hard time distinguishing certain shades of red and green. This type of color vision deficiency is inherited as an X-linked trait. X-linked inheritance means that the gene causing the trait is located on the X chromosome. Women have two X chromosomes and men have one X chromosome and one Y chromosome. The Y chromosome predominantly carries genes that are responsible for male development and it does not contain genes that are responsible for color vision. If a man inherits an X chromosome with a gene on it that causes color blindness, that man will be affected. If a woman inherits an X chromosome with a gene on it that causes color blindness, she will likely have a working copy of that same gene on h
