Mitochondrial DNA (mtDNA) is a hereditary material located in mitochondria and is normally maternally inherited. Mutational analysis performed on mtDNA proved that the mutations are closely related with a number of genetic illnesses, besides being exploitable for forensic identification. Those findings imply the importance of mtDNA in the scientific field. MtDNA can be found in abundance in tooth dentin where it is kept protected by the enamel, the hardest outer part of the tooth. In this study, two techniques of mtDNA extraction were compared to determine the efficacy between the two techniques. Teeth used for the study was collected from Dental Clinic, Hospital Universiti Sains Malaysia. After the removal of tooth from the tooth socket of the patient, the tooth was kept at -20C until use. Later, pulp tissue and enamel was excised using dental bur and only the root dentin was utilized for the isolation of mtDNA by crushing it mechanically into powdered form. MtDNA was extracted using the two published methods, Pfeifer and Budowle and then subjected to spectrophotometry DNA quantification and purity, Polymerase chain reaction (PCR) amplification of hypervariable-two region of mtDNA, followed by DNA sequencing to analyze the reliability of the extraction techniques. In conclusion, both techniques proved to be efficient and capable for the extraction of mtDNA from tooth dentin.

Introduction: Chronic lymphocytic leukaemia (CLL) is the most frequent adult leukaemia in the Western world. The clinical presentation varies greatly, from very indolent cases to those with aggressive and fast advancing disease. This variation has significant implications for clinical approaches, therapeutic tactics, and, ultimately, survival durations from diagnosis. Acquired chromosomal aberrations play a key role in CLL aetiology. Due to difficulty to obtain abnormal metaphases for analysis, few methods such as fluorescence in-situ hybridization (FISH) and multiplex ligation-dependent probe assay (MLPA) were employed to detect chromosomal aberration however the methods are limited to specific locus only. Thus, this study is aimed to detect the chromosomal aberrations using DNA microarray platform. Methods: In this retrospective study, DNA archive obtained from 7 CLL patients which collected at diagnosis and subjected to Affymetrix CytoScan® 750K single nucleotide polymorphism (SNP) array following the manufacture procedure. The raw data obtained were analysed using the Chromosome Analysis Suite (ChAS) software (Affymetrix) using annotations of genome version GRCh38 (hg38). Result: Out of 7 patients, 4 of them showing deletion of 13q while 3 of them showing deletion of 14q in various region . Some of the deleted loci were too small (0.42-0.6Mb) to be detected by conventional cytogenetic analysis (CCA). There was also the presence of additional chromosomal aberrations that could be missed by CCA, FISH, or MLPA due to cryptic deletion or duplication that was as small as 0.4MB in size. Conclusion: The present study showed that low resolution chromosomal aberration was able to be detected using DNA microarray platform in comparison to CCA, FISH and MLPA.

Introduction: Imatinib mesylate has been widely used as a standard treatment for chronic myeloid leukemia (CML). It acts as a selective competitive inhibitor of the BCR-ABL tyrosine kinase. Despite the excellent efficacy on CML treatment, some patients developed resistance to the treatment. Mutation in the PDGFRA may be one of the factors involved in the mechanism of resistance that affects the response to imatinib. The mutational status of PDGFRA is highly relevant for prognosis and treatment prediction in CML patients. Thus, this study is intended to establish and validate a High Resolution Melting (HRM) analysis for PDGFRA exon 10 c.1432 T>C polymorphism in CML patients. Methods: High resolution melting (HRM) analysis was used to identify the c.1432 T > C polymorphism in PDGFRA exon 10 (n =86; response = 43; resistance = 43). The results from HRM analysis were compared and validated with Sanger sequencing. The association between the polymorphism and treatment response was assessed by statistical analysis using binomial logistic regression analysis. Results: HRM analyses showed two different melt curves. One curve followed the shape of the reference, homozygous wild type (TT) and the other curve showed a different melting profile than the reference with the TC genotype (heterozygous variant). The results revealed that heterozygous variant (TC) genotype showed a high risk of acquiring resistance with an OR of 3.795; 95% CI: 1.502-9.591, with a statistically significant association, p = 0.005. HRM analysis also showed 100% sensitivity and specificity in the detection of PDGFRA exon 10. Conclusion: The HRM analysis of PDGFRA exon 10 c.1432 T>C was successfully established. The exon 10 c.1432 T>C polymorphism shows a higher risk for the development of resistance toward imatinib treatment.