FRM1 gene CGG sequence repeat detection method and application

Abstract

The invention discloses an FRM1 gene CGG sequence repeat detection method and application. The FRM1 gene CGG sequence repeat detection method is characterized by including the following implementation steps that two pairs of primers are designed and respectively internal reference primers and detection primers, one pair of internal reference primers are located at the 5' end of a CGG repeat region, and the other pair of detection primers cross over the whole GGG repeat region; when the number of CGG repeats in the region covered with the detection primers ranges from 0 to 200, a (470+3n)bp fragment is added, wherein n is the number of the CGG repeats; when the number of CGG repeats in the region covered with the detection primers is larger than 200, the reaction is limited by the experiment condition, no fragment is added. By the adoption of the technology, two different products are added in the same reaction system, and sample genetypes are identified through comparison of the products with DNA markers. The method can be used for detecting the FRM1 gene CGG sequence repeats, can assist people in rapidly and conveniently finding carriers and patients with fragile X syndrome disease genes, and can be applied to prenatal diagnosis, make pregnant women abort infants with a fragile X syndrome, and reduce morbidity of the fragile X syndrome.

Description

technical field [0001] The invention belongs to the fields of biotechnology and medicine, especially molecular biology and polymerase chain reaction. Background technique [0002] The FMR1 gene is located at q27.3 of the X chromosome, with a sequence length of about 38kb, consisting of 17 exons and 16 introns, encoding the Fragile X mental disability gene protein (FMRP). The FMR1 gene is a highly conserved gene, and there is a (CGG)n trinucleotide tandem repeat sequence in the untranslated region of its 5' end exon, and the (CGG)n fragment has a polymorphism in the repeat pattern, And can be inherited, there is a CpG island about 250bp upstream of it. The value of n in normal FMR1 gene (CGG) n ranges from 7 to 54. When n increases to 54 to 200, although the carrier phenotype is normal, it is prone to further expansion during the passage process. This FMR1 gene mutation is called a pre-mutation of the FMR1 gene. The CpG islands in the premutated FMR1 gene are generally not...

AI Technical Summary

Problems solved by technology

Fragile X syndrome has a high incidence rate, complicated clinical manifestations, and clear genetic rules. At present, there is no effective treatment method. child born

[0004] At present, the detection methods for FMR1 gene mainly include RFLP linkage analysis, DNA hybridization analysis, PCR amplification and other methods, but due to the high content of CG in the CGG sequence repeat region and CpG island of FMR1 gene, the DNA melting of FMR1 gene and the extension of primers are difficult. become very difficult

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