Exon Sequencing Of The Budd-chiari Syndrome

Background and purposePathogenesis and etiology of primary Budd-Chiari syndrome(BCS) are complex and there are obvious regional differences between eastern and western countries. In the US and Europe and other western countries, the etiology of primary BCS is associated with the formation of venous thrombosis. The current research has found that the gene mutations of JAK2 V617F、FⅤL、FⅡG20210A、MTHFR are associated with primary BCS. These genes are risk factors for thrombosis, which together with a variety of external factors cause that the patient’s blood is in a hypercoagulable state, and the formation of hepatic vein thrombosis leads to hepatic vein obstruction and eventually evolves into the primary BCS; however, in Japan, China and India and other Asian regions, related genes with high expression in the western countries are less expressed, so the related genes of primary BCS in eastern countries are still in an unknown state.With the rapid development of molecular biology techniques, next generation of sequencing technology with its unique advantage of high-throughput and low-cost, makes the human whole genome sequencing possible, and also brings new hope for the research of primary BCS related genes. Traditional Sanger sequencing is widely used in the research of gene structure, but its low data output flux, high cost, complicated operation defects make it limited in a deeper level of gene research. Compared with Sanger sequencing, NGS sequencing flux is thousands of times or even tens of thousands of times higher, but its cost is only one thousandth of the former. Relying on NGS platform, many scholars have found gene mutation that had never found before, showing its unlimited potential for future field of genetic research.Through genome-wide exome sequencing technology, all exons of patients with primary BCS were screened in order to find specific gene mutations, for further discussing the pathogenesis and etiology of primary BCS.Primary BCS is a rare clinical syndrome, but in Henan Province, Anhui Province and other regions in China, the incidence was significantly higher with obvious geographical and familial aggregation phenomenon. Finding the possible pathogenic genes, primary BCS can be early detected and prevented for high-risk groups in the early stage. Method 1. Case collectionA Primary BCS family is in long-term follow up. The family consists of 8 people(5 men, 3 women), all received inferior vena cava ultrasonography and CT imaging, and 3 are diagnosed with primary BCS. Peripheral venous blood samples are collected. 2. exome sequencingAccording to the standard process of exome sequencing, extract the genomic DNA, establish the library, sequence the exons, sequence the exons by machine, analysis the biological information, and confirm the candidate genes. 3. data analysisThrough literature review, protein function prediction and mutation frequency, summarize the candidate genes of interest. 4. The candidate gene validationCandidate gene PCR / sanger sequencing. ResultThe results of exome sequencing and bioinformatics analysis showed that 2 patients had a total of 53 gene mutations, in which screened out two mutations: HSPG2 c.C4508TGPR126 c.T3242 G. These two mutations have been verified positive validation results. ConclusionTwo newly discovered gene mutations(HSPG2 c.C4508 T and GPR126 c.T3242G) may be closely associated with inferior vena cava diaphragmatic type of Budd-Chiari syndrome.