Men are much more likely to be colourblind (iRochromatic) than women because the genes responsible for the most common, inherited colour blindness are on the X chromosome.
Colour Blind Genetic Inheritance
Here’s the technical stuff – Males only have one X chromosome, while females have two X chromosomes. In females, a functional gene on only one of the X chromosomes is enough to compensate for the loss on the other. This kind of inheritance pattern is called X-linked, and primarily affects males. Inherited colour blindness can be present at birth, begin in childhood, or not appear until the adult years.
How Color blind Genetics are Inherited?
In X-linked inheritance, the mother carries the mutated gene on one of her X chromosomes and will pass on the mutated gene to 50 per cent of her children.
Because females have two X chromosomes, the effect of a mutation on one X chromosome is offset by the normal gene on the other X chromosome. In this case, the mother will not have the condition, but she can pass on the mutated gene and so is called a carrier. If a mother is a carrier of an X-linked condition, (and the father is not affected), there is a:
• 1 in 2 chance that a son will have the condition,
• 1 in 2 chance that a daughter will be a carrier of the condition,
• No chance that a daughter will have the v.
In autosomal recessive inheritance, it takes two copies of the mutant gene to give rise to the disease. An individual who has one copy of a recessive gene mutation is known as a carrier. When two carriers have a child, there is a:
• 1 in 4 chance of having a child with the condition,
• 1 in 2 chance of having a child who is a carrier,
• 1 in 4 chance of having a child who neither has the condition nor is a carrier.
In autosomal dominant inheritance, it takes just one copy of the mutant gene to bring about the condition, When an affected parent with one dominant gene mutation has a child, there is a 1 in 2 chance that a child will inherit the condition.
