There are many genetic diseases, congenital, familial, and lifelong. According to the characteristics of heritability, they are basically divided into three categories: monogenic diseases, polygenic inheritance, and chromosomal abnormalities. Monogenic diseases are further divided into dominant, recessive, and sex-linked inheritance. Dominant inheritance means that one parent has a dominant gene, and once passed to the next generation, the disease will develop and be passed from generation to generation, such as having polydactyly, syndactyly, primary glaucoma, etc. Recessive inheritance means that both parents are normal in appearance but are carriers of disease-causing genes, such as congenital deafness, high myopia, albinism, etc. Sex-linked inheritance means that if the mother is a carrier of the disease-causing gene, it is passed on to the son; if the father is a carrier of the disease-causing gene, it is passed on to the daughter, such as hemophilia and red-green color blindness, which are more prevalent in males than females. Polygenic inheritance means that there are multiple genetic variations and influences causing them, such as length, body size, intelligence, skin color and blood pressure are polygenic, as well as cleft lip, cleft palate, asthma, schizophrenia, etc., which are more influenced by environmental factors. Chromosomal abnormalities, which are caused by abnormal number or arrangement of chromosomes, are most commonly seen in congenital dysmorphism, congenital heart disease, albinism, phenylketonuria, trisomy 21, gonadal dysgenesis, etc.