Development of a high-resolution melting method for the screening of TNFAIP3 gene mutations

Comparison Between Three Molecular Diagnostics for the Identification of Heterozygous Hemoglobin E

BACKGROUND AND OBJECTIVES

Hemoglobin E is a variant hemoglobin caused due to the base substitution G→A at codon 26 in the β-globin-coding gene that is followed by the alteration of glutamic acid (GAG) to lysine (AAG). Various types of molecular analysis methods such as tetra-primer amplification refractory mutation system (T-ARMS-PCR), Tm-shift real-time polymerase chain reaction (Tm-shift qPCR) and high-resolution melting analysis (HRMA) are commonly used to detect several mutations in the β-globin-coding gene. This study was conducted to compare the detection result of Cd 26 (G→A) mutation in the β-globin-coding gene of heterozygous HbE between the above-mentioned methods.

MATERIALS AND METHODS

DNA samples were isolated from blood archive of heterozygous HbE and analyzed for the detection of the mutation using HRMA and Tm-shift on a real-time PCR instrument, whereas T-ARMS analysis was performed on a conventional PCR equipment. High resolution melt v3.1 software and Bio-Rad CFX Manager software were used to analyze the result of HRMA and Tm-shift qPCR, whereas the T-ARMS-PCR result was analyzed by observing the number and size of DNA bands on gel electrophoresis.

RESULTS

Among 21 samples, the Cd 26 mutation was detected in numbers 18, 19 and 21 by HRMA, Tm-shift qPCR and T-ARMS-PCR. DNA Sequencing confirmed Cd 26 mutation on 5 ambiguous samples and revealed two homozygous mutation.

CONCLUSION

The Cd 26 (G→A) mutation was detected in proportions 100, 91 and 86% by T-ARMS-PCR, Tm-shift qPCR and HRMA, respectively.

Association of IL28B SNPs rs12979860 and rs8099917 on Hepatitis C Virus-RNA Status in Donors/Recipients of Living Donor Liver Transplantation

To investigate the effect of IL28B single nucleotide polymorphisms (SNPs) (rs8099917 and rs12979860) in the donors and recipients on the outcome of Hepatitis C virus-RNA clearance after living donor liver transplantation (LDLT). The rs8099917 and rs12979860 genotypes in 50 donor and recipients pairs were explored on the pre-operative day (POD) and post-operative day 30 (POD30). There was a significant difference in HCV-RNA clearance before (12%, 6/50) and after (48%, 24/50) liver transplantation (P < 0.001). The rs8099917 genotype TT was dominant in both the recipients (82%, 41/50) and donors (86%, 43/50), but had no significant effect on HCV-RNA clearance (87.5%, 21/24) and recurrence (76.9%, 20/26) after LDLT. One recipient was detected with genotype GG on POD, which changed to genotype GT on POD30. Prevalence of rs12979860 genotype CT was 98% (49/50 recipient) and 92% (46/50 donor) and prevalence of genotype CC was 2% (1/50 recipient) and 8% (4/50 donor) on POD and POD30, respectively. Of the 4 recipients with rs12979860 genotype CC on POD30, 3 recipients (12.5%, 3/24) exhibited HCV clearance and 1 experienced recurrence (3.9%, 1/26), however, this was not statistically significant. In conclusion, alterations in IL28B SNP genotype may occur after LDLT, leading to modifications in the host genome or donor proteome by HCV. This predicted mechanism will need to be investigated further.