Chromosomal abnormality

Chromosome abnormalities, also known as chromosome dysgenesis, refer to abnormal numbers of chromosomes and structural aberrations. The chromosome consists of DNA and proteins, and most genes are located in the DNA of the chromosome. The chromosome is the basic substance that makes up the nucleus of cells, and is the carrier of genes. Chinese American Jiang Youxing (1956) identified 46 human chromosomes, and Caspersson et al. (1970) first published photographs of human chromosomal bands. Since the Paris International Chromosome Naming Conference in 1971, more than 3,000 human chromosomal abnormalities and structural aberrations have been discovered. At present, more than 100 chromosome disease syndromes have been identified. Mental retardation and growth retardation are common characteristics of chromosome diseases.