Detection method of SNP site of SMA gene

Abstract

The invention provides a detection method of an SNP (single nucleotide polymorphism) site of an SMA gene. The method comprises the following steps of (S10) performing a polymerase chain reaction (PCR), and amplifying a nucleic acid fragment including an SNP site; (S20) performing a dephosphorylation reaction on the nucleic acid fragment; (S30) performing an extension reaction on the nucleic acid fragment, wherein an extension primer is used for identifying the position of the SNP site, and single nucleotide which is in base complementarity with the SNP site is extended at a 3' end of the extension primer so that an extended extension primer is obtained; (S40) performing a purifying reaction to purify the extended extension primer; and(S50) detecting the size of the molecular weight of theextended extension primer, and according to the size of the molecular weight, determining the kind of bases of the extended single nucleotide, so that according to the kind of the bases of the SNP site in the SMA gene (including an SMN1 gene and an SMN2 gene), determining whether SMN1 gene homozygosis deletion occurs or not.

Description

technical field [0001] The invention relates to a detection method for gene defect, especially a detection method for SNP (single nucleotide polymorphism) site of SMA gene. Background technique [0002] The cause of Spinal Muscular Atrophy is the decline and degeneration of the motor nerves in the anterior horn of the spinal cord due to genetic defects, resulting in gradual weakness and paralysis of the muscles, accompanied by symptoms of muscle atrophy. The muscle atrophy is symmetrical, The lower extremities are more severe than the upper extremities and the proximal end of the body is more susceptible than the distal end. So far there is no treatment. It is divided into three types according to the severity: [0003] Severe spinal muscular atrophy (Werdnig-Hoffmann Disease, SMA type I): About one in every 20,000 babies is the most common type. In the womb or within three months after birth, the baby will experience symptoms such as weakness of limbs, weak cry and difficu...

AI Technical Summary

Problems solved by technology

[0007] The current methods for detecting SMN1 gene defects are quantitative polymerase chain reaction (real-time PCR) or direct sequencing, but no matter which method is used, there are problems of low sensitivity, high cost and low efficiency.

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