(1) Family history: Special attention should be paid to the accuracy of the family history due to the patient’s and surrogate’s lack of accuracy or incompleteness in the description of symptoms and signs due to literacy, memory, thinking ability, judgment and mental status, or due to false information provided by the patient or surrogate. (2) Marital history: focus on understanding the age of marriage, the number of times, the health of the spouse and whether the marriage is consanguineous. (3) Birth history: chromosomal abnormalities account for 50% of miscarried embryos, 8‰ of stillbirths, 6‰ of neonatal deaths, and 5-10‰ of newborn babies, so it is very important to ask about birth history, focusing on the age of birth, number of children and health status, and whether there is a history of miscarriage, stillbirth and preterm birth. If there is a newborn death or a child, in addition to the above-mentioned information of parents and family members, we should also find out whether the child has any birth injury, asphyxia, toxic diseases and exposure to teratogenic factors in early pregnancy, such as history of taking teratogenic drugs or exposure to ionizing radiation or chemical substances. 2. Symptoms and signs: Routine physical examination. (1) Common clinical manifestations of autosomal disorders are: congenital non-progressive intellectual abnormalities, growth retardation, often accompanied by malformations of the five senses, limbs, internal organs, etc. (2) The common clinical features of sex chromosome syndromes are: hypogonadism or hermaphroditism, with some patients showing only reduced fertility, secondary amenorrhea, slightly poorer intelligence, and abnormal behavior. (3) Since most of the genetic diseases have signs and symptoms in infancy or childhood, in addition to the physical characteristics, we should also pay attention to the speed of physical development, the rate of weight gain, the improvement of intelligence, the development of sexual organs and secondary sex characteristics, the strength of muscle tone and the abnormal sound of crying. (4) To make a preliminary diagnosis of chromosomal disorders and the type of chromosomal disorders they may belong to by comparing the phenotypic characteristics of chromosomal disorders and the human chromosome group disease chart. 3. Laboratory diagnosis: Chromosome examination: Chromosome examination, also known as karyotype analysis, is the main method to confirm the diagnosis of chromosomal disorders. With the application of banding technology and the emergence and improvement of high-resolution chromosomal banding technology, more chromosomal number and structure abnormalities syndromes can be more accurately determined and detected, and new microalteration syndromes can also be detected. It is important to note that chromosomal examination should be analyzed in conjunction with clinical manifestations to arrive at a correct diagnosis. The source of chromosome examination specimens is mainly taken from peripheral blood, chorionic villi, fetal shed cells in amniotic fluid and various tissues such as umbilical cord blood and skin.