Gene polymorphism directly leads to the selective diversity of transcription and translation in the process of biological reproduction, allowing the transmission of genetic code to maintain a certain accuracy and a certain degree of tolerance. This kind of moderate reproduction Flexibility is important to the stability and diversity of the biological world.

The substitution, deletion, and insertion of bases in genetic polymorphisms lead to changes in the nucleotide sequence of the coding sequence. In the process of transcription and translation to synthesize proteins, they cause changes in the genetic code and in the protein peptide chain. Fragment deletions, abnormal mRNA splicing, or mutations in promoters and non-transcribed regions. Some increase or decrease the transcription level or activity of genes, and affect the sequence of amino acids in the polypeptide chain. The biological effects of these genetic polymorphisms can be divided into: Nonsense mutation refers to a codon that originally translated a certain amino acid into a stop codon due to base substitution. For example, the transversion of UAU (amino acid) into UAA (stop codon) terminates the synthesis of the polypeptide chain, forming an incomplete polypeptide chain, which changes the biological activity and function of the protein. Transformations can also cause nonsense mutations.

Both nonsense mutations and deletions of DNA fragments can lead to the deletion of fragments in the peptide chain, causing the protein encoded by the gene to lose its original function. Frame-shifting mutation refers to the deletion or insertion of a single base or several bases in the coding sequence. The deletion or insertion of the fragment can change the reading frame of the triplet codon after the mutation site, making it impossible to code. The original normal protein.

Frameshift mutations not only change the amino acid sequence in the translated peptide chain, but also cause the deletion of large fragments in the peptide chain. Abnormal splicing refers to the deletion of several bases, fragment deletions, chromosomal mutations, etc., which may cause the deletion and abnormality of mRNA splicing sites, which can lead to incorrect splicing of mRNA, produce abnormal mRNA, and ultimately produce abnormal expression products.

If a point mutation occurs at the splicing site of an intron, it will affect the splicing of mRNA: either the original splicing site will disappear, or a new splicing site will be generated.