Are gene microdeletions and microreplications necessarily pathogenic?

On the whole, yes. There are many kinds of gene mutation, and only one is nonsense mutation, which will not cause pathological changes. Other mutations are generally less harmful and can treat diseases. For example, microdeletion of Y chromosome will lead to male infertility, and the repetition of one base (CGG) on X chromosome greater than 45 will lead to congenital stupidity, that is, mental retardation, and so on. So now we advocate genetic testing. If there is a disease, targeted treatment can be guided according to genetic testing. If there is no disease, the risk of illness can be predicted and prevented in advance. It can also give birth to excellent children and ensure the quality of birth.