Application of reagents for detecting the KCNJ8 gene c.263C>G mutation in the preparation of diagnostic products for hereditary arrhythmias.

Abstract

This invention discloses the application of a reagent for detecting the c.263C>G mutation in the KCNJ8 gene in the preparation of diagnostic products for hereditary arrhythmias. The technical solution provided by this invention significantly improves the prevention and treatment efficacy of hereditary arrhythmias at the clinical level. Using ARMS-PCR technology, the detection of the KCNJ8-A88G mutation can be completed within 45 minutes, with a sensitivity of 99.8% accurately identifying mutation allele frequencies as low as 0.1%, greatly shortening the diagnostic cycle compared to traditional sequencing. At the treatment level, screening for KATP channel inhibitors can effectively prevent the occurrence of arrhythmias after myocardial infarction. The "genotype-phenotype-treatment response" association model established by this invention not only improves the prevention and treatment of diseases such as J-wave syndrome but also sets a benchmark for the translation from basic laboratory research to clinical application.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, specifically to the application of reagents for detecting the c.263C>G mutation in the KCNJ8 gene in the preparation of diagnostic products for hereditary arrhythmias, and the application of KATP channel inhibitors in malignant arrhythmias. Background Technology

[0002] Inherited Cardiac Conditions (ICCs) are a group of heart diseases caused by gene mutations and can be passed down within families. They mainly affect the electrical activity of the heart (arrhythmias) or its structure (cardiomyopathy), significantly increasing the risk of sudden death and heart failure. Among these diseases, hereditary arrhythmias have become a focus of research in the cardiovascular field due to their insidious onset and high mortality rate. J-wave syndromes (JWS) and ischemia-related ventricular arrhythmias are the most clinically challenging phenotypes.

[0003] J-wave syndromes are a group of inherited arrhythmias characterized by significant J waves accompanied by ST-segment elevation on electrocardiograms (ECGs). They primarily include two subtypes: Early Repolarization Syndrome (ERS) and Brugada Syndrome (BrS). These syndromes can lead to sudden cardiac death (SCD) by inducing polymorphic ventricular tachycardia (VT) and ventricular fibrillation (VF). The typical ECG manifestation of Brugada Syndrome is significant J-point elevation and characteristic ST-segment changes in the right precordial leads, often accompanied by right ventricular conduction abnormalities. Early repolarization syndrome is characterized by a prominent J wave at the end of the QRS complex, J-point elevation, notching, or abrupt changes, which can be distributed in lateral precordial leads (Type I), inferior or inferior lateral leads (Type II), and anterior, inferior lateral, and right ventricular leads (Type III). Premature repolarization (ERP) is traditionally considered a benign finding, but recent studies have shown that certain types of ERP are closely associated with an increased risk of idiopathic ventricular fibrillation and sudden death.

[0004] Regarding the genetic mechanisms, the molecular basis of J-wave syndrome is not fully understood. Currently, only the SCN5A gene has been confirmed to have a clear clinical association with BrS, while the pathogenicity of the remaining 20-plus non-SCN5A genes remains controversial. SCN5A variants account for 20-25% of BrS cases and 10% of ERS cases. In addition to SCN5A, eight other genes have been confirmed to be associated with ERS. The KCNJ8 gene encodes the Kir6.1 subunit of the ATP-sensitive potassium channel (KATP), and mutations in it have been reported to be associated with both BrS and ERS.

[0005] KATP channels are heteromeric complexes composed of the Kir6.x subunit (Kir6.1 / Kir6.2) and the SURx subunit (SUR1 / SUR2A / SUR2B), with KCNJ8 encoding the inward rectifying potassium channel Kir6.1. These channels have a sophisticated regulatory mechanism: they are inhibited when intracellular ATP levels rise, and when nucleotides react with magnesium ions (Mg²⁺) to inhibit ATP. 2+ When KATP channels bind to ATP, they are activated, thereby increasing potassium conductance. This regulation is crucial for maintaining myocardial homeostasis. Under metabolic stress conditions such as hypoxia or ischemia (15), KATP channel activation promotes potassium efflux, shortens action potential duration, and enables the heart to maintain function under adverse conditions. Therefore, KATP current not only participates in preconditioning regulation but is also a core component of cardiac metabolic response. Mutations in KATP channels (especially the KCNJ8 gene) can lead to serious cardiovascular disease: the KCNJ8-S422L missense mutation was reported in a young female patient with significantly worsened ERP leading to recurrent ventricular fibrillation. Our team and the Medeiros-Domingo team confirmed that this mutation enhances KATP channel current by reducing the channel's sensitivity to ATP. In addition, the KCNJ8-V65M and C176S mutations found in patients with Cantu syndrome also lead to increased KATP channel function.

[0006] Ventricular arrhythmias (VT / VF) following acute myocardial infarction (AMI) are a significant cause of early sudden cardiac death and long-term mortality. Studies by Hu et al. have found a close association between SCN5A gene mutations and arrhythmia storms during acute ischemic episodes, suggesting a possible genetic susceptibility to ventricular arrhythmias following myocardial infarction. KATP channels are a key component of ischemic preconditioning, a protective mechanism that enhances the heart's tolerance to persistent hypoperfusion. Impaired channel function affects the maintenance of myocardial energy homeostasis under ischemic conditions. For example, the V734I mutation in the ABCC9 gene has been shown to increase susceptibility to AMI.

[0007] Despite significant progress in research on hereditary arrhythmias, numerous challenges remain in clinical practice. At the diagnostic level, approximately 70% of J-wave syndrome patients lack a clearly identifiable pathogenic gene, and there is a lack of unified standards for assessing the pathogenicity of non-SCN5A genes. Current gene testing primarily relies on SCN5A screening, and testing for potential pathogenic genes such as KCNJ8 has not yet been incorporated into routine clinical procedures, causing some patients to miss opportunities for early intervention. Currently, treatment for hereditary arrhythmias mainly relies on implantable cardioverter-defibrillators (ICDs) and nonspecific antiarrhythmic drugs, lacking precise intervention methods based on molecular mechanisms. Summary of the Invention

[0008] The main objective of this invention is to propose the application of a reagent for detecting the c.263C>G mutation in the KCNJ8 gene in the preparation of diagnostic products for hereditary arrhythmias. The aim is to provide a rapid and highly sensitive diagnostic method for detecting pathogenic genes, as well as drugs for targeted treatment of hereditary arrhythmias related to KCNJ8 gene mutations.

[0009] To achieve the above objectives, this invention proposes the application of a reagent for detecting the c.263C>G mutation in the KCNJ8 gene in the preparation of diagnostic products for hereditary arrhythmias.

[0010] Preferably, the hereditary arrhythmia includes J-wave syndrome and post-myocardial infarction ventricular fibrillation.

[0011] Preferably, the diagnostic products include gene chips and gene detection kits.

[0012] Preferably, the diagnostic product is a kit, which includes a forward primer with the sequence shown in SEQ ID NO:1 and a reverse primer with the sequence shown in SEQ ID NO:2.

[0013] This invention also proposes the application of an inhibitor targeting the KATP channel in the preparation of a drug for treating hereditary arrhythmias related to the KCNJ8 gene c.263C>G mutation.

[0014] Preferably, the inhibitor includes sulfonylurea derivatives.

[0015] Preferably, the inhibitor includes glibenclamide.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) The technical solution provided by this invention significantly improves the prevention and treatment efficacy of hereditary arrhythmias at the clinical diagnosis and treatment level. KCNJ8-A88G mutation detection can be completed within 45 minutes using ARMS-PCR technology, with a sensitivity of 99.8% that can accurately identify mutation allele frequencies as low as 0.1%. It supports detection of various sample types, including peripheral blood and oral swabs, and significantly shortens the diagnostic cycle compared to traditional sequencing. At the treatment level, KATP channel inhibitors designed based on Kir6.1 can prevent ventricular arrhythmias in hereditary heart disease and the occurrence of electrical storm after myocardial infarction.

[0018] (2) This invention possesses both outstanding scientific research transformation value and socio-economic benefits, propelling cardiovascular precision medicine into a new stage. The high-throughput screening capability of the HEK293-A88G stable cell line, capable of processing 500 compounds daily, provides precise tools and structural basis for targeted drug development. This full-chain innovation, from gene discovery to structural analysis to clinical application, is the first to transform KATP channel biology research into a diagnostic and treatment standard, providing a research paradigm for other ion channel diseases such as long QT syndrome. Economically, it significantly reduces medical costs by reducing unnecessary ICD implantation (saving $50,000 per patient per year) and avoiding the side effects of traditional drugs. Its established "genotype-phenotype-treatment response" correlation model not only improves the prevention and treatment of diseases such as J wave syndrome but also sets a benchmark for transformation from basic laboratory research to clinical application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 These are electrocardiogram records of patients with J-wave syndrome and post-myocardial infarction ventricular fibrillation in Embodiment 1 of the present invention.

[0021] Figure 2 The diagram shows the gene mutation site detection results in Example 2 of the present invention; A is the Sanger sequencing diagram of the exon2 region of the wild-type KCNJ8 gene; B is the Sanger sequencing diagram of the exon2 region of the mutated KCNJ8 gene.

[0022] Figure 3Figure A shows the functional verification results of KATP-A88G mutant cells in Example 3 of this invention; Figure B shows the effect of the A88G mutation in the KCNJ8 gene on the current of the KATP channel; Figure C shows the current density bars of the mutant channel at stimulation voltages of 0mV and 40mV, respectively.

[0023] Figure 4 The diagram shows the inhibitory effect of the mutant cell KATP channel inhibitor on KATP channel current in Example 4 of this invention; A~B are the opening frequencies of single KATP channels in wild-type and mutant cells recorded by single-channel patch clamp; C is the IKATP current-voltage relationship recorded by single-channel cell patch clamp; D is the change in the opening time constant of wild-type and mutant KATP channels at -60mV stimulation voltage; E is the inhibitory effect of different concentrations of KATP channel inhibitors on KATP channels; F is the concentration dependence of KATP channel opening probability on KATP channel inhibitor concentration.

[0024] Figure 5 This is an experimental diagram showing the effect of mutant cell KATP channel inhibitors on post-myocardial infarction arrhythmias in Example 5 of the present invention.

[0025] Figure 6 This diagram illustrates the mechanism by which the A88G mutation in the KCNJ8 gene affects KATP channel function and cardiac electrophysiology.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0029] Example 1: Screening for mutated genes in patients with clinical hereditary arrhythmias

[0030] This invention included 413 clinically diagnosed patients with J-wave syndrome (JWS) and 25 patients with ventricular fibrillation (VF) following acute myocardial infarction (MI). JWS patients were diagnosed by electrocardiogram (J-wave amplitude ≥0.1mV with / without ST-segment elevation) and medical history (excluding secondary causes). VF patients following MI were defined as those who developed VF within 24 hours of MI onset without any apparent cause. Figure 1 The image shows electrocardiogram (ECG) recordings of some patients with J-wave syndrome and post-myocardial infarction ventricular fibrillation. All patients were fully informed, informed of the purpose of the procedure, and obtained their consent by signing an informed consent form. Five mL of peripheral venous blood was collected for DNA extraction.

[0031] Next-generation sequencing (NGS) was used to capture and sequence the target regions of 136 arrhythmia-related genes in all patients. After software alignment, quality control, and database screening, the KCNJ8 c.263C>G (A88G) missense mutation was discovered for the first time in both population groups. This mutation targets KCNJ8 exon2, and the C→G base variation leads to the transformation of alanine to glycine at position 88, i.e., the KCNJ8-A88G gene mutation. It is speculated that this mutation affects the conformational changes of the Kir6.1 channel, leading to abnormal myocardial repolarization and increasing the risk of disease.

[0032] Example 2: KCNJ8-A88G Mutation Validation and Rapid Detection

[0033] 1. Sample collection and DNA extraction

[0034] Sample type: Peripheral venous blood, oral swabs, or myocardial biopsy tissue are selected based on the patient's clinical condition;

[0035] DNA extraction: A commercial kit (such as the Gentra Puregene Blood Kit) was used and the procedure was followed according to the instructions. Peripheral blood samples were lysed with red blood cells and white blood cells to precipitate DNA. Oral swabs / myocardial tissue samples were digested with proteinase K to extract DNA.

[0036] Quality control: DNA concentration and purity were determined using Nanodrop 2000, requiring a 260 / 280 ratio >1.8. DNA integrity was verified by 1% agarose gel electrophoresis (no obvious degradation bands). Qualified DNA was stored at -20℃ for later use.

[0037] 2. Mutation detection (PCR + Sanger sequencing)

[0038] (1) PCR amplification (targeting KCNJ8 exon2)

[0039] Primer design: Specific primers were designed targeting exon 2 of the KCNJ8 gene (containing the c.263C>G mutation site):

[0040] Forward primer (SEQ ID NO:1): 5'-GCCTTCGTGCTCATCTTC-3'

[0041] Reverse primer (SEQ ID NO:2): 5'-TGGTGAAGAGGCTGAGGA-3'

[0042] The PCR reaction system is as follows.

[0043] Table 1 PCR reaction system

[0044]

[0045] PCR reaction conditions: 95℃ pre-denaturation for 5 min; 35 cycles (95℃ for 30 s → 62℃ annealing for 30 s → 72℃ extension for 30 s); 72℃ final extension for 5 min; product stored at 4℃.

[0046] (2) Sanger sequencing verification

[0047] Product purification: Qiagen PCR Purification Kit was used to remove impurities such as primers and dNTPs from the PCR products;

[0048] Sequencing reaction: ABI 3730 sequencer was used to perform bidirectional sequencing with PCR primers as sequencing primers to read the KCNJ8exon2 sequence;

[0049] The results are as follows Figure 2 As shown, the sequencing results were compared with the NCBI reference sequence (NM_004982.4), and the 263rd base was detected to be C→G, which was determined to be the KCNJ8 c.263C>G (p.A88G) mutation.

[0050] (3) Rapid detection (ARMS-PCR)

[0051] Allele-specific primers were designed for the A88G mutation:

[0052] Wild-type (A88) detection primer: 5'-GCTCATCTTCCGGCATC-3' (amplifies only the C allele)

[0053] Detection primers for mutant (G88): 5'-GCTCATCTTCGGGCATC-3' (amplifies only the G allele)

[0054] Detection procedure: Using the PCR reaction system in Table 1 above, wild-type / mutant primers were added for amplification, and the products were detected by 2% agarose gel electrophoresis; gene detection was performed based on the gel electrophoresis results.

[0055] Example 3 Functional verification of the KCNJ8-A88G mutation

[0056] 1. Cell Model Construction

[0057] (1) Plasmid construction

[0058] First, the wild-type KCNJ8 expression plasmid (pcDNA3.1-KCNJ8-WT) was constructed: The full-length coding sequence of KCNJ8 (reference sequence NM_004982.4) was obtained by PCR amplification from a human myocardial tissue cDNA library. The amplification product and pcDNA3.1(+) vector were digested with restriction endonucleases, ligated with T4 DNA ligase, transformed into DH5α competent cells, plated on antibiotic-containing plates to screen positive clones, and single colonies were picked for culture. The plasmid was extracted and verified by Sanger sequencing to ensure that the inserted KCNJ8 sequence was complete and free of base mutations, thus constructing the wild-type recombinant plasmid.

[0059] Construction of the mutant plasmid pcDNA3.1-KCNJ8-A88G: Using pcDNA3.1-KCNJ8-WT as a template, the mutant plasmid (pcDNA3.1-KCNJ8-A88G) was constructed using the QuikChange site-directed mutagenesis kit. A high-fidelity DNA polymerase (e.g., Phusion) was used to amplify the circular plasmid containing the mutation site. DpnI restriction enzyme was added (37℃ for 1 h) to degrade the methylated original template plasmid (preserving the mutant product). The plasmid was transformed into DH5α competent cells, plated on antibiotic-containing plates for screening positive clones, and single colonies were picked, cultured, and the plasmid extracted and verified by Sanger sequencing.

[0060] Construction of the control plasmid pcDNA3.1-ABCC9-WT: The full-length coding sequence of ABCC9 was obtained by PCR amplification from a human myocardial tissue cDNA library. The amplification product and the pcDNA3.1(+) vector were digested with restriction endonucleases (EcoRI / NotI), respectively. After ligation with T4 DNA ligase, the cells were transformed into DH5α competent cells, plated on antibiotic-containing plates to screen for positive clones, and single colonies were picked for culture. The plasmid was extracted and verified by Sanger sequencing to ensure that the inserted ABCC9 sequence was complete and free of base mutations, thus constructing the wild-type recombinant plasmid.

[0061] (2) Cell transfection

[0062] HEK293 cells (ATCC CRL-1573) were cultured in DMEM high-glucose medium containing 10% fetal bovine serum and 1% penicillin-streptomycin at 37°C in a 5% CO2 incubator until the logarithmic growth phase. 24 hours before transfection, cells were sputtered at a rate of 3 × 10⁻⁶ cells / mL. 5 Seeds were placed into 24-well plates (or electrophysiology-specific glass-bottomed culture dishes) at a density of 1 cell per well. Transfection experiments could be performed when the cell density reached approximately 75%.

[0063] One hour before transfection, replace the culture medium in each well with antibiotic-free DMEM (containing 10% fetal bovine serum) to reduce toxicity to cells. Prepare the transfection system: Take 2 μg of KCNJ8-WT or KCNJ8-A88G plasmid per well and mix it with 2 μg of ABCC9-WT plasmid (1:1 ratio). Simultaneously add 0.2 μg of GFP-labeled plasmid and dilute to 125 μL with Opti-MEM serum-depleted medium. Gently mix to obtain the plasmid mixture. Separately, take 8 μL of Lipofectamine 3000 reagent and dilute to 125 μL with Opti-MEM. After standing at room temperature for 5 minutes, obtain the liposome dilution. Slowly mix the plasmid mixture with the liposome dilution and incubate at room temperature for 15 minutes to form a stable plasmid-liposome complex.

[0064] Add the complex dropwise to the wells of the HEK293 cells, gently shake the culture plate to distribute the complex evenly, and incubate at 37°C with 5% CO2 for 6 hours. Then replace the medium with complete culture medium containing antibiotics (to avoid liposome toxicity) and continue incubation for 42 hours (total incubation time 48 hours) to ensure full expression of the target protein.

[0065] Forty-eight hours after transfection, GFP expression was observed using a fluorescence microscope (excitation wavelength 488 nm). Five fields of view were randomly selected to count the proportion of GFP-positive cells. Only cells with a transfection efficiency of ≥70% could be used for subsequent functional experiments.

[0066] 2. Electrophysiological analysis (patch clamp)

[0067] (1) Whole-cell recording

[0068] Pre-prepared electrode intracellular solution (mM): 140 KCl, 10 NaCl, 2 MgCl2, 1 EGTA, 10 HEPES (pH 7.3). Freshly prepared extracellular solution (mM): 130 NaCl, 5 KCl, 1 MgCl2, 0.1 CaCl2, 10 glucose, 10 HEPES (pH 7.4). Whole-cell patch-clamp technique was used to detect changes in cellular KATP current. Glass microtubes were drawn into electrodes with an impedance of 2-5 Ω, filled with electrode intracellular solution, and a small amount of cell suspension was placed in the perfusion tank. After standing for several minutes, the cells adhered to the tank, forming a high-resistance seal. Negative pressure was applied to rupture the cell membrane, compensating for slow capacitance and series resistance (80%-85%), thus establishing whole-cell recording mode. IKATP was recorded using the following stimulation protocol: voltage ramp: -120 mV → +100 mV (400 ms), recording the glibenclamide-sensitive current (10 μM blocking).

[0069] (2) Single-channel recording (inside-out)

[0070] Configuring symmetrical high K + Solution (mM): 140 KCl, 1 CaCl2, 1 MgCl2, 10 EGTA, 10 HEPES (pH 7.2) were used as the inner and outer solutions for the electrode. A glass microtube was drawn into an electrode with an impedance of 8-10 Ω. The electrode was filled with the inner solution, and a small amount of cell suspension was placed into the perfusion tank. After standing for several minutes, the cells adhered to the wall and formed a high-resistance seal. The membrane was ruptured, and the electrode was quickly lifted to detach the membrane from the cell and expose it to the bath solution (inner cell side facing out) to form a whole-cell recording mode. IKATP was recorded. The stimulation protocol was: recording potential -80 mV → +80 mV, step 20 mV, and recording the glibenclamide-sensitive current (10 μM blocking).

[0071] The results are as follows Figure 3 As shown in Figure A, the A88G mutation in the KCNJ8 gene enhances the current in the KATP channel, affecting its electrophysiological properties. Figure 3 B showed a significant increase in current density of the mutation channel at stimulation voltages of 0 mV and 40 mV (p < 0.05).

[0072] Example 4 Drug Screening

[0073] HEK293 cells transfected with wild-type and mutant plasmids were used as selection cells. Drug screening was performed using single-channel patch-clamp technique. Extracellular solution: 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 10 mM HEPES (pH 7.4); Intracellular solution: 140 mM KCl, 5 mM EGTA, 1 mM MgATP, 10 mM HEPES (pH 7.2). The inhibitory effect of KATP channel inhibitors on KATP current was tested.

[0074] The results are as follows Figure 4 As shown, Figure 4 A~B reflects the opening frequency of a single KATP channel in wild-type and mutant individuals recorded by single-channel patch clamp. Channels carrying the A88G mutation have enhanced function and increased opening frequency. Figure 4 C reflects the IKATP current-voltage relationship recorded by single-channel cell patch-clamp, showing that the current of the mutation channel is enhanced under different stimulation voltages; Figure 4 D reflects the opening time constant of wild-type KATP channels and mutant KATP channels at a stimulation voltage of -60 mV, with the opening time of mutant channels being significantly prolonged (p < 0.01). Figure 4 E reflects the inhibitory effect of different concentrations of KATP channel inhibitors on KATP channels. Compared with wild type, mutant channels are less responsive to K2ATP, but when the K2ATP concentration reaches 100 mmol / L, KATP channel current can be completely inhibited. Figure 4 F reflects the concentration dependence of the KATP channel opening probability on the KATP channel inhibitor concentration.

[0075] Example 5: Experimental study on the effect of inhibitors on hereditary arrhythmias

[0076] An acute myocardial infarction mouse model was established using 8-12 week old C57BL / 6 mice. The mice were anesthetized with 1.5-2% isoflurane inhalation, connected to a small animal ventilator, and prepared with a left 4th intercostal incision to expose the heart. The left anterior descending artery (LAD) was ligated 1-2 mm below the left atrial appendage using 7-0 silk sutures. Immediately after ligation, the anterior wall of the left ventricle turned pale. The muscle and skin were sutured layer by layer, and the mice were kept warm and resuscitated postoperatively. The mice were given a KATP inhibitor (glibenclamide 0.2 mg / kg) by gavage daily for one month, with dynamic monitoring of electrocardiograms to observe the occurrence of arrhythmias.

[0077] The results are as follows Figure 5 As shown, Figure 5 The electrocardiogram of the "myocardial infarction + KATP channel inhibitor" group showed a regular sinus rhythm with a neat waveform; Figure 5 The electrocardiograms of group B, the "myocardial infarction" group, showed ventricular fibrillation patterns; Figure 5C is a bar chart showing the incidence of arrhythmias in different treatment groups (control group, myocardial infarction group, and myocardial infarction + KATP channel inhibitor group). The chart shows that the number of ventricular tachyarrhythmias in the myocardial infarction + KATP channel inhibitor group was significantly lower than that in the myocardial infarction group. Figure 5 The results showed that mice in the myocardial infarction group were more prone to ventricular arrhythmias, while mice in the KATP inhibitor myocardial infarction group had a lower incidence of arrhythmias.

[0078] Figure 6 This diagram illustrates the mechanism by which the A88G mutation in the KCNJ8 gene affects KATP channel function and cardiac electrophysiology. It shows the relationship between KCNJ8-A88G mutation → enhanced KATP channel function → K... + Increased outflow → cardiac electrophysiological disorders → the complete mechanism chain of diseases such as BrS, ERS, and VF.

[0079] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. Application of reagents for detecting the c.263C>G mutation in the KCNJ8 gene in the preparation of diagnostic products for J-wave syndrome and / or ventricular fibrillation after myocardial infarction.

2. The application as described in claim 1, characterized in that, The diagnostic products include gene chips and gene testing kits.

3. The application as described in claim 2, characterized in that, The diagnostic product is a kit, which includes a forward primer with the sequence shown in SEQ ID NO:1 and a reverse primer with the sequence shown in SEQ ID NO:2.

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