Developing an Amplification Refractory Mutation System-Quantitative Reverse Transcription-PCR Assay for Rapid and Sensitive Screening of SARS-CoV-2 Variants of Concern

The current stage of the pandemic, led by SARS-CoV-2 variants of concern (VOCs), underscores the necessity to develop a cost-effective and rapid molecular diagnosis assay to differentiate the VOCs. In this study, over 1 million SARS-CoV-2 genomic sequences of high quality from GISAID were analyzed and a network of the common mutations of the lineages was constructed.

Preimplantation Genetic Diagnosis in Hereditary Hearing Impairment

Sensorineural hearing impairment is a common sensory deficit in children and more than 50% of these cases are caused by genetic etiologies, that is, hereditary hearing impairment (HHI). Recent advances in genomic medicine have revolutionized the diagnostics of, and counseling for, HHI, including preimplantation genetic diagnosis (PGD), thus providing parents-to-be with better reproductive choices. Over the past decade, we have performed PGD using the amplification refractory mutation system quantitative polymerase chain reaction (ARMS-qPCR) technique in 11 couples with a history of HHI, namely eight with GJB2 variants, one with OTOF variants, one with SLC26A4 variants, and one with an MITF variant. We demonstrated that PGD can be successfully applied to HHI of different inheritance modes, namely autosomal dominant or recessive, and phenotypes, namely syndromic or non-syndromic HHI. However, certain ethical concerns warrant scrutiny before PGD can be widely applied to at-risk couples with a history of HHI.

Association of BTNL2 gene single nucleotide polymorphism with knee osteoarthritis

Relevance. Osteoarthritis (OA) is one of the chronic debilitating condition mostly seen in the aged population. The etiology behind the OA is multifactorial and the exact cause of the disease often remains uncertain. Apart from the conventional risk factors, there are the speculations of role of genetics playing a pivotal role in the causation of OA. The available literature showed BTNL2 gene polymorphism association with risk of Osteoarthritis whether the same relation is present in north Indian population needs to be elucidated. Objective. To find the association between single nucleotide polymorphism (SNP) (rs10947262) in BTNL2 gene and the susceptibility in knee Osteoarthritis (OA) subjects from northern Indian population. Materials and Methods. Blood samples of 100 patients of knee osteoarthritis and 100 healthy subjects were collected after institutional ethical clearance and participants consent. The BTNL2 gene fragment was amplified using Amplification Refractory Mutation System (ARMS-PCR) with predesigned primers after DNA extraction. The corresponding product bands were identified on the gel electrophoresis for 200 samples and the results were statistically analyzed. Results and Discussion. The genotypic distribution of the SNP followed Hardy-Weinberg Equilibrium. The genotype frequency analysis of the polymorphism was statistically significant (2=7.788; P=0.005) with Odds Ratio of CT+TT/CC: OR=2.303; P=0.008 revealing association of BTNL2 polymorphism with risk of Knee Osteoarthritis. Conclusion. The SNP (rs10947262) in the BTNL2 gene region is associated with risk of knee osteoarthritis.

Universal probe-based intermediate primer-triggered qPCR (UPIP-qPCR) for SNP genotyping

Background The detection and identification of single nucleotide polymorphism (SNP) is essential for determining patient disease susceptibility and the delivery of medicines targeted to the individual. At present, SNP genotyping technology includes Sanger sequencing, TaqMan-probe quantitative polymerase chain reaction (qPCR), amplification-refractory mutation system (ARMS)-PCR, and Kompetitive Allele-Specific PCR (KASP). However, these technologies have some disadvantages: the high cost of development and detection, long and time consuming protocols, and high false positive rates. Focusing on these limitations, we proposed a new SNP detection method named universal probe-based intermediate primer-triggered qPCR (UPIP-qPCR). In this method, only two types of fluorescence-labeled probes were used for SNP genotyping, thus greatly reducing the cost of development and detection for SNP genotyping. Results In the amplification process of UPIP-qPCR, unlabeled intermediate primers with template-specific recognition functions could trigger probe hydrolysis and specific signal release. UPIP-qPCR can be used successfully and widely for SNP genotyping. The sensitivity of UPIP-qPCR in SNP genotyping was 0.01 ng, the call rate was more than 99.1%, and the accuracy was more than 99.9%. High-throughput DNA microarrays based on intermediate primers can be used for SNP genotyping. Conclusion This novel approach is both cost effective and highly accurate; it is a reliable SNP genotyping method that would serve the needs of the clinician in the provision of targeted medicine.

An Early-Onset Advanced Rectal Cancer Patient With Increased KRAS Gene Copy Number Showed A Primary Resistance to Cetuximab in Combination With Chemotherapy: A Case Report

Mutations in KRAS (codon 12/13), NRAS, BRAFV600E, and amplification of ERBB2 and MET account for 70–80% of anti-epidermal growth factor receptor (EGFR) monoclonal antibody primary resistance. However, the list of anti-EGFR monoclonal antibody primary resistance biomarkers is still incomplete. Herein, we report a case of wild-type RAS/BRAF metastatic colorectal cancer (CRC) with resistance to anti-EGFR monoclonal antibody and chemotherapy. Initially, mutation detection in postoperative tumor tissue by using amplification-refractory mutation system polymerase chain reaction indicated wild-type RAS/BRAF without point mutations, insertion deletions, or fusion mutations. Therefore, we recommended combined therapy of cetuximab and FOLFIRI after failure of platinum-based adjuvant chemotherapy, but the disease continued to progress. Next generation sequencing analysis of the postoperative tumor tissue revealed that KRAS copy number was increased and detected SMAD4, RNF43, and PREX2 mutations. This is the first case of advanced CRC with increased copy numbers of KRAS resistant to cetuximab and chemotherapy, which results in poor patient survival, and other mutated genes may be associated with the outcomes. Our findings indicate KRAS copy number alterations should also be examined, especially with anti-EGFR monoclonal antibody therapy in CRC, since it may be related with the primary resistance to these drugs.

Effect of APOB polymorphism rs562338 (G/A) on serum proteome of coronary artery disease patients: a “proteogenomic” approach

In the current study, APOB (rs1052031) genotype-guided proteomic analysis was performed in a cohort of Pakistani population. A total of 700 study subjects, including Coronary Artery Disease (CAD) patients (n = 480) and healthy individuals (n = 220) as a control group were included in the study. Genotyping was carried out by using tetra primer-amplification refractory mutation system-based polymerase chain reaction (T-ARMS-PCR) whereas mass spectrometry (Orbitrap MS) was used for label free quantification of serum samples. Genotypic frequency of GG genotype was found to be 90.1%, while 6.4% was for GA genotype and 3.5% was for AA genotypes in CAD patients. In the control group, 87.2% healthy subjects were found to have GG genotype, 11.8% had GA genotype, and 0.9% were with AA genotypes. Significant (p = 0.007) difference was observed between genotypic frequencies in the patients and the control group. The rare allele AA was found to be strongly associated with the CAD [OR: 4 (1.9–16.7)], as compared to the control group in recessive genetic model (p = 0.04). Using label free proteomics, altered expression of 60 significant proteins was observed. Enrichment analysis of these protein showed higher number of up-regulated pathways, including phosphatidylcholine-sterol O-acyltransferase activator activity, cholesterol transfer activity, and sterol transfer activity in AA genotype of rs562338 (G>A) as compared to the wild type GG genotype. This study provides a deeper insight into CAD pathobiology with reference to proteogenomics, and proving this approach as a good platform for identifying the novel proteins and signaling pathways in relation to cardiovascular diseases.

Analysis of beta globin gene mutations in Diyarbakir

Objectives Hemoglobin disorders are quite heterogeneous in the Turkish population. Up to now, more than forty different beta thalassemia mutations and 60 hemoglobin variants have been characterized in the country. The aim of this study was to investigate genetic heterogeneity of HBB gene mutations in patients and their parents at Southeastern Anatolia in Turkey. Methods Genomic DNA was isolated from 145 thalassemic patients’ blood samples and their parents in this study. Ten different HBB gene mutations HBB:c.-80T>A, HBB:c.17_18delCT, HBB:c.25_26delAA, HBB:c.92+1G>A, HBB:c.92+5G>C, HBB:c.92+6T>C, HBB:c.93-21G>A, HBB:c.135delC, HBB:c.315+1G>A, HBB:c.316-106C>G were screened by amplification refractory mutation system. Four Hb variants and some rare beta thalassemia mutation were characterized by DNA sequencing. Results In this study, 97 homozygous and 48 compound heterozygous thalassemic patients were diagnosed by molecular genetic analyses. As a results, 18 β-thalassemia mutations and four abnormal hemoglobins; HBB:c.20A>T, HBB:c.364G>C, HBB:c.34G>A and HBB:c.208G>A were detected at Dicle University Hospital. Conclusions In the results, HBB:c.93-21G>A is the most common mutation in the region. Three mutations [(HBB:c.93-21G>A), (HBB:c.25_26delAA) and (HBB:c.135delC)] account for about 58 per cent of all the point mutations. Except HBB:c.20A>T and HBB:c.364G>C, two silent Hb variants (HBB:c.34G>A and HBB:c.208G>A) were detected in this study. Hb Hamilton [β11 (GTT>ATT) Val>Ile] was seen first time in Turkey.

AURKC Gene Polymorphism (rs58264281) Associated with Idiopathic Male Infertility Risk in Northeast of Iran: A Case-Control Study

Background: Infertility is a major public health and social problem in human reproduction that is known as a multifactorial complex disorder. Genetic background and mutations and single nucleotide polymorphisms (SNPs) on the genes involved in sperm development are the important causes of male infertility. Objectives: In this study, we evaluated the association of AURKC gene polymorphism (rs58264281) and idiopathic male infertility in the Iranian Azeri population. Methods: This study was performed among 100 men with idiopathic infertility (case group) and 100 healthy men with successful fertility (control group) from East Azerbaijan, Iran. Genomic DNA extraction was carried out from peripheral blood samples by the proteinase K method. Genotype analysis was conducted by the tetra-primer amplification refractory mutation system-polymerase chain reaction (Tetra-ARMS PCR). SPSS version 21 was used for the analysis of the obtained data. Results: We observed that the CA and AA genotypes were significantly increased in patients with infertility as compared to healthy controls. Our results demonstrated that the mutant allele of AURKC gene polymorphism (rs58264281) was a significant risk factor in male infertility. Conclusions: We suggested a significant correlation between the AURKC gene rs58264281 polymorphism and male infertility in the Iranian Azeri population. However, further studies are required among other ethnicities, races, and geographic areas with larger sample sizes.

Genetic heterogeneity of beta thalassemia mutations in Kahramanmaraş province in Southern Turkey: preliminary report

Background: Beta thalassemia is one of the most common autosomal single-gene disorders in the world. The prevalence of the disease is in the “thalassemia belt” which includes the Mediterranean region of Turkey; throughout the country the gene frequency is estimated to be 2.1%, but in certain regions, this figure increases to 10%. Aim: In this first study, we aimed to determine the frequency of β-thalassemia trait and distrubition of mutations in Kahramanmaraş province, which is located in the southern part of Turkey. Materials and Methods: In this study; 5 ml blood samples was taken from 14 thalassemic patients and their relatives who were taking care of Sutcu Imam University Hospital at Kahramanmaraş. Also, we collected blood samples from 245 adults for screening beta thalassemia trait. Haematological data were obtained by cell counter.  HbA2 was determined by HPLC. Ten common mutations were screened by ARMS  (Amplification Refractory Mutation System) method. These β-thalassemia mutations are -30 (T>A), Fsc8 (-AA), Fsc8/9 (+G), IVS1-1 (G>A), IVS1-5 (G>C), IVS1-6 (T>C), IVS1-110 (G>A ), Cd 39 ( C>T), IVS2-1 (G>A), IVS 2-745 (C>G). A rare mutation; Fsc44 (-C) was charecterized by DNA sequencing. Results: Ten patients were detected as homozygous for IVS1-110 (seven cases), Fsc 44 (two cases) and IVS1-5 (only one case). Rest of the 4 patients were double heterozygous (two: IVS1-110/IVS1-6, one: Fsc8/Fsc8-9, one: IVS2-1/IVS1-5). In 245 adult, five  β-thalassemia trait were detected by screening survey.  Conclusion: Sixteen alleles were detected as IVS1-110 in 57.1%. It was seen the most common mutation in Kahramanmaraş. Seven different β-thalassemia mutations were found in this study. Each of 10 families have only one thalassemic patient, other two families have double thalassemic patient in total 12 family.