Small amplicons high resolution melting analysis (SA-HRMA) allows successful genotyping of acid phosphatase 1 (ACP1) polymorphisms in the Italian population

High resolution melting profiles (HRMPs) obtained by magnetic induction cycler (MIC) have been used to monitor the BRCA2 status highlighted by next generation tumor sequencing (NGTS): a combined approach in a diagnostic environment

Resistance can be the result of secondary tissue variants (STVs), which restore the open reading frame of the germline BRCA allele, producing functional BRCA protein in germline BRCA1/2 (BRCA) pathogenic variant (PV) carriers, treated with platinum-based chemotherapy or poly-(ADP-ribose) polymerase inhibitors (PARP-1). We reported recently a BRCA2 mutant high grade serous ovarian cancer (HGSOC) patient with acquired resistance to the PARP-1 olaparib due to a STV detected by next generation tumor sequencing (NGTS). The aim of this study was to evaluate the versatility of the high-resolution melting analysis (HRMA) obtained by magnetic induction cycler (MIC) to monitor the BRCA2 status in formalin-fixed paraffin-embedded (FFPE) tissue samples of this patient and to compare the results obtained by NGTS. HRMA highlighted the BRCA2 STV previously detected in the IIIrd HGSOC recurrence following the tissue BRCA2 tissue status comparing the high resolution melting profiles (HRMPs). HRMPs differentiate not only BRCA2 alleles, but also their different allele abundance. We underline that (1) the MIC uses a latest generation technology guaranteeing temperature uniformity and maintenance in each well allowing high and accurate performance to obtain reported results and (2) the HRMA maintains a high sensitivity and specificity when it is performed on FFPE samples. Finally, this study represents an additional use of the HRMA, confirming its extreme versatility in the diagnostic environment.

High-resolution melting combines with Bayes discriminant analysis: a novel hepatitis C virus genotyping method

Current hepatitis C virus (HCV) genotyping techniques are often highly technical, costly, or need improvements in sensitivity and specificity. These limitations indicate the need of novel methods for HCV genotyping. The present study aimed to develop a novel genotyping method combining high-resolution melting (HRM) analysis with Bayes discriminant analysis (BDA). Target gene fragment including 5'-untranslated and core region was selected. Four or five inner amplicons for every serum were amplified using nested PCR, HRM was used to determine the melting temperature of the amplicons, and HCV genotypes were then analyzed utilizing BDA. In initial genotyping (HCV genotypes were classified into 1b, 2a, 3a, 3b, and 6a), both the overall accuracy rate and the cross-validation accuracy rate were 92.6 %, external validation accuracy rate was 95.0 %. To enhance the accuracy rate of genotyping, HCV genotypes were firstly classified into 1b, 3a, 3b, and 2a-6a, followed by a supplementary genotyping for 2a-6a. Both the overall accuracy rate and the cross-validation accuracy rate reached 97.5 %, and external validation accuracy rate was 100 %. Comparing adjusted HRM genotyping with type-specific probe technique, the difference in accuracy rates was not significant. However, the limit of detection and cost were lower for HRM. Comparing with sequencing, the limit detection of HRM was the same as the former, but the cost of HRM was lower. Hence, HRM combined with BDA was a novel method that equipped with superior accuracy, high sensitivity, and lower cost and therefore could be a better technique for HCV genotyping.

Correlation between thyroglobulin gene polymorphisms and autoimmune thyroid disease

The aim of the present study was to detect thyroglobulin (Tg) gene polymorphisms in a Han Chinese population from the Northern regions of Henan province, China, and to study the correlation between Tg gene polymorphisms and autoimmune thyroid disease (AITD). A total of 270 patients with AITD and 135 healthy controls were enrolled. Genomic DNA was extracted and fluorescence polymerase chain reaction analysis was performed; high‑resolution melting curve analysis (HRMA) was used to detect single‑nucleotide polymorphisms (SNPs) in exons 10, 12 and 33 of the Tg gene. SNPs were then correlated with AITD. Han people from the Northern regions of Henan displayed four Tg exon SNPs: E10SNP24 T/G, E10SNP158 T/C, E12SNP A/G and E33SNP C/T. Several allele and genotype frequencies differed between the AITD group and the healthy control group (Tg E10SNP: Allele T, P<0.01; allele G, P<0.01; and Tg genotype GG, P<0.01; genotype TG, P<0.01. Tg E12SNP: Allele A, P<0.01; allele G, P<0.01; Tg genotype GG, P<0.01; genotype AG, P<0.01). A statistically significant difference in the frequency of selected Tg SNPs haplotypes was also present between AITD patients and healthy controls (P<0.05). There was no significant difference in haplotypes between various types of AITD (hypothyroidism, hyperthyroidism and Hashimoto's disease). The Tg SNP frequency distribution was significantly different between Han populations of the Northern regions of Henan province and the Xi'an regions of Shaanxi province. The results of the present study suggested that specific Tg gene alleles or genotypes were correlated with AITD; specific Tg SNP haplotypes were associated with hypothyroidism, hyperthyroidism and Hashimoto's disease, and the Tg SNP frequency distribution differed depending on the geographical location of the Han Chinese populations.