Xiao Li went to her cousin’s house to play, accompanying her cousin’s son Tian Tian to build blocks. Tian Tian is already one year and nine months old and is very lively and cute. Xiao Li finds that Tian Tian Tian is very good at learning the shapes and sizes of the blocks, but he can’t distinguish the colors clearly and talks nonsense. Remembering that her father and uncle were both red-green colorblind, Xiao Li suspected that Tian Tian was also colorblind and suggested that her cousin go to the hospital to have Tian Tian tested as soon as possible. Remembering her baby plan again, Xiao Li started to collect information about color blindness online. After learning that she was a carrier, she was even more worried that her future baby would be like Tian Tian. Can color blindness be hereditary? Will Xiao Li have a healthy child? Let’s find out what color blindness is and how it is inherited and how to avoid it. What is color blindness? The scientific name for color blindness is congenital color vision disorder, which is the inability to distinguish between various colors or a certain color in the natural spectrum. Color blindness is divided into total color blindness and partial color blindness. Red-green color blindness is the most common form of partial color blindness, with a prevalence of about 5% in men and 0.6% in women. Some people can see the colors that normal people see, but have poor color discrimination, which is called color blindness. Etiology of color blindness Color blindness is divided into congenital color blindness and acquired color blindness. Red-green colorblindness is a recessive form of congenital colorblindness that is inherited in a consanguineous manner. Scientists have found that red-green color blindness depends on two pairs of genes on the X chromosome, namely the red-blind gene and the green-blind gene. Since these two pairs of genes are closely interlocked on the X chromosome, red and green colorblindness often appear at the same time, manifesting as red-green colorblindness. Given that red-green colorblindness is recessive, it only manifests as color blindness when both X chromosomes carry the color blindness gene in females. If only one X chromosome carries the color blindness gene, the woman behaves normally. However, because she carries the disease-causing gene, she is called a carrier. A male with only one X chromosome, on the other hand, will show color blindness if he carries the color blindness gene. Therefore, males are far more likely to have color blindness than females. From the above theory, if a normal female marries a colorblind male, the male’s colorblind gene can be passed on with the X chromosome to their daughter (i.e., a carrier), producing a son who is normal. The daughter then passes on the colorblind gene from her father to her son, a phenomenon known as crossover inheritance. If a colorblind woman marries a normal man, both sons will be colorblind and the daughters will be carriers. Xiao Li’s father is colorblind, so Xiao Li is a carrier. If Xiao Li is married to a normal male, there is a 1/2 chance that Xiao Li will have a son with red-green colorblindness; if she has a girl, there is a 1/2 chance that she will be a carrier and a 1/2 chance that she will be normal, neither of which will show red-green colorblindness. As you can see, it may be wise to have a girl in cases where one parent carries the color blindness gene. Impact of color blindness on life Red-green color blindness is a common disorder. Patients grow up without normal color discrimination and should not be noticed, often only during medical examinations. Because red-green colorblind patients cannot distinguish red from green, they are not suitable for jobs that require high color vision, such as art, textile, printing and dyeing, and chemical industry. Other than that, there is no significant impact on the patient’s normal life, just a lesser perception of the colorful world. Because red-green color blindness is a non-fatal lesion, prenatal diagnosis is not recommended.