How is color blindness inherited?

How is color blindness inherited?

Red-green color blindness, the most common form by far, is a genetic mutation that is passed to children on the X chromosome. At conception, an egg carries an X chromosome and the sperm cell can carry either an X chromosome or a Y chromosome. If you have an XX chromosome pair, the resulting baby will be female. If you have an XY chromosome pair, the baby will be male. The gene responsible for color blindness is located on the X chromosome. In other words, red-green color blindness is an X-linked recessive condition. If a female inherits one normal color vision gene and one mutated gene, she won’t be red-green color blind, because it’s a recessive trait. If she inherits two mutated color vision genes, she’ll be color red-green blind.

Since boys have only one X chromosome, their chance of inheriting red-green color blindness is much greater. Boys always inherit their X chromosome from their mother. If mom has red-green color blindness, or if mom’s dad is red-green colorblind, her son will be too.