Heredity, which generally belongs to autosomal recessive inheritance and dominant inheritance, has the following three modes: 1. Parents have normal phenotype, but they all have deaf-mute genes. Parents have deaf-mute genes and will give birth to a deaf-mute child. If one parent is a deaf-mute gene carrier and not deaf-mute, then the next generation may also be a deaf-mute gene carrier, but not deaf-mute. 2. Then all the children born are deaf and dumb, regardless of gender. Childbearing is not allowed in this situation. One parent is born deaf and dumb, and the child born may be half sick and half normal, which is calculated according to the genetic law.