1. Baldness
The creator seems to favor women, so that baldness is passed on only to men. For example, if a father is bald, the probability of passing it on to his son is 50%. Even a mother’s father will leave 25% of his bald head to his grandchildren. This genetic tendency of passing on male to female makes men helpless.
Scientists from the University of Bonn, Germany, after studying some families with baldness, concluded that baldness is related to genetic factors, and to a large extent comes from the genetic factors of mothers. The findings are published in the July issue of the American Journal human genetics. Scientists have long suspected that genetic factors are an important cause of hair loss.
Men usually inherit an X chromosome from their mother, while women inherit an X chromosome from both parents. So, when heredity is associated with hair loss, men are likely to inherit grandfather’s hair loss.
2. Hemophilia
Hemophilia is a disease only passed on to boys. With this disease, the blood is not easy to coagulate due to the lack of a clotting substance. Therefore, slight injury will cause more than bleeding, even no injury, but also subcutaneous and intra-articular bleeding. If cerebral hemorrhage occurs, it will be fatal.
Hemophilia is a group of congenital coagulation factor deficiency, resulting in hemorrhagic disease. Congenital factor VIII deficiency is a typical sex linked recessive inheritance, which is transmitted by women and developed by men. The gene controlling the synthesis of coagulation components of factor VIII is located on the X chromosome.
The marriage between the sick man and the normal woman, the male children are normal, and the female is the carrier; Half of the children were male patients and half of the children were female carriers; Half of the boys were born with hemophilia, half of the girls were born with hemophilia and half of the carriers were born with hemophilia. About 30% of them have no family history, and the disease may be caused by gene mutation.
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