A boy born to a mother with a genetic disease gene will have a 50% chance of getting sick, while a girl will become a carrier, and the child born to this girl may also get sick in the future. Give a few examples:
1, hemophilia, the pathogenic gene is located on the X chromosome, which belongs to a typical linked recessive inheritance. So if the mother carries the disease-causing gene, she will pass X on to her son, and his son will get sick. Daughters generally don't get sick because they accept their father's normal X.
2. Baldness (androgenetic alopecia) is a common hair disease, which is located on the X chromosome. Although the disease is related to the patient's age, local androgen level, mental factors, sleep, sebum secretion, diet and other factors, it is generally considered to be an androgen-dependent genetic disease. If the father is bald, the son is bald 50%. Grandpa is bald, and his grandson is bald 50% of the time. If grandpa and dad are bald, then
3, red and green color blindness, color blindness genes only exist on the X chromosome, but not on the Y chromosome. Therefore, the mother has a color blindness gene, and the son born accepted the mother's X and the father's Y, which is the color blindness gene. If the father has the color blindness gene, the daughter will have it and the son will not. The daughter born will be passed on to the grandson in the future.
Father's Y chromosome carries genetic disease gene, which belongs to Y chromosome genetic disease, and there is no obvious recessive difference. All the males in the offspring of patients are patients. There are the following diseases:
1, azoospermia and severe oligozoospermia, and the inheritance belongs to copy deletion of DAZ gene in AZFc region of Y chromosome.
2. hirsutism of external auditory canal is a y-linked genetic symptom recognized by scholars. This disease is common in Indians.
3. It is also proved that toe-webbed porcupine disease (a rare skin disease) belongs to Y chromosome inheritance.
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