I
idocsteve
Guest
So yeah. I know colour blindness isn't that common but it's one in seven.
Closer to 1 in 10. Males only.
This is because the gene for Red/Green Color deficiency is transmitted via the X Chromosome and is recessive, the term is "recessive X-linked genetic disorder" and is responsible for Hemophilia A, Duchenne muscular dystrophy, red-green color blindness, Muscular dystrophy and Androgenetic alopecia (yes I cheated and Googled this part).
A woman would have to be double recessive to be colorblind and that's extremely rare, a fraction of a percent.
All colorblind men will give the gene to their daughters who will be carriers, and of children born to those daughters, half of their sons will be colorblind and half of their daughters will be carriers. A father cannot pass the gene to his son because he gives the son his Y chromosome.