Chromosome examination is mainly to check whether the number and structure of chromosomes are abnormal, such as whether there is 2 1 trisomy syndrome, that is, there is one more chromosome 2 1 or sex chromosome, that is, there is one more X chromosome and one more Y chromosome, which is called abnormal number. The elderly are prone to chromosomal abnormalities, or have given birth to children in poor health, or their immediate family members have given birth to similar children, or have repeated miscarriages or stillbirths after giving birth. To do chromosome examination, chromosomal mutation's duplication or deletion will lead to diseases.
2 1 trisomy syndrome is a mental retardation. If there is one more X or one less X, such as 45XO, it is Turner syndrome. If there is 47xxxxy or 47xxxxy, there may be chromosomal abnormalities such as super girl and super boy syndrome. In addition, there are some structures, such as the exchange, duplication or deletion of this chromosome with the long arm and short arm of another chromosome, which can also lead to diseases.