A novel three-round multiplex PCR for SNP genotyping with next generation sequencing.

Owing to the high throughput and low cost, next generation sequencing has attracted much attention for SNP genotyping application for researchers. Here, we introduce a new method based on three-round multiplex PCR to precisely genotype SNPs with next generation sequencing. This method can as much as possible consume the equivalent amount of each pair of specific primers to largely eliminate the amplification discrepancy between different loci. After the PCR amplification, the products can be directly subjected to next generation sequencing platform. We simultaneously amplified 37 SNP loci of 757 samples and sequenced all amplicons on ion torrent PGM platform; 90.5 % of the target SNP loci were accurately genotyped (at least 15×) and 90.4 % amplicons had uniform coverage with a variation less than 50-fold. Ligase detection reaction (LDR) was performed to genotype the 19 SNP loci (as part of the 37 SNP loci) with 91 samples randomly selected from the 757 samples, and 99.5 % genotyping data were consistent with the next generation sequencing results. Our results demonstrate that three-round PCR coupled with next generation sequencing is an efficient and economical genotyping approach. Graphical Abstract The schematic diagram of three-round PCR.

[The reason and treatment of portal vein thrombosis in patients with portal hypertension postoperation].

OBJECTIVE: To investigate reason and the management of portal vein thrombosis in patients with portal hypertension postoperatively. METHODS: 329 patients with portal hypertension in liver cirrhosis who had splenectomy was reviewed from 1992 to 2001. In whom 43 (13.1%) patients with portal vein thrombosis postoperative were analyzed. RESULTS: In these patients, except 1 died for portal vein phlebitis, all patients were recovered. There are 138 patients who underwent splenectomy or splenectomy and devascularization, 26 (18.8%) of them had thrombosis. 191 patients underwent splenectomy and portacaval or portasplenic shut, 17 (8.9%) of them had thrombosis. The data of these two groups have significant difference (chi(2) = 8.44, P < 0.01). CONCLUSIONS: Thrombocytosis postsplenectomy as well as the changes of portal hemodynamics is the main reason of portal vein thrombosis. Portal vein thrombosis is also in association with the operative ways. Operation standardization, dynamic examining platelet count, routine color ultrasonography examining and early anticoagulation therapy are the effective methods in preventing and managing portal thrombosis postoperation for portal hypertension.