Gene Mutation Spectrum among Alpha-Thalassaemia Patients in Northeast Peninsular Malaysia.

(1) Background: Alpha (α)-thalassaemia is a genetic disorder that affects 5% of the world population. Deletional or nondeletional mutations of one or both HBA1 and HBA2 on chromosome 16 will result in reduced production of α-globin chains, a component of haemoglobin (Hb) that is required for the formation of red blood cells (RBCs). This study aimed to determine the prevalence, haematological and molecular characterisations of α-thalassaemia. (2) Method: The parameters were based on full blood count, high-performance liquid chromatography and capillary electrophoresis. The molecular analysis involved gap-polymerase chain reaction (PCR), multiplex amplification refractory mutation system-PCR, multiplex ligation-dependent probe amplification and Sanger sequencing. (3) Results: With a total cohort of 131 patients, the prevalence of α-thalassaemia was 48.9%, leaving the remaining 51.1% with potentially undetected α gene mutations. The following genotypes were detected: -α3.7/αα (15.4%), -α4.2/αα (3.7%), --SEA/αα (7.4%), αCSα/αα (10.3%), αAdanaα/αα (0.7%), αQuong Szeα/αα (1.5%), -α3.7/-α3.7 (0.7%), αCSα/αCSα (0.7%), -α4.2/αCSα (0.7%), -SEA/αCSα (1.5%), -SEA/αQuong Szeα (0.7%), -α3.7/αAdanaα (0.7%), --SEA/-α3.7 (2.2%) and αCSα/αAdanaα (0.7%). Indicators such as Hb (p = 0.022), mean corpuscular volume (p = 0.009), mean corpuscular haemoglobin (p = 0.017), RBC (p = 0.038) and haematocrit (p = 0.058) showed significant changes among patients with deletional mutations, but not between patients with nondeletional mutations. (4) Conclusions: A wide range of haematological parameters was observed among patients, including those with the same genotype. Thus, a combination of molecular technologies and haematological parameters is necessary for the accurate detection of α-globin chain mutations.

Sequencing analysis of exons 5 and 6 in RUNX2 in non-syndromic patients with supernumerary tooth in Kelantan, Malaysia.

OBJECTIVE: The aim of this study is to do a sequencing analysis of RUNX2 in non-syndromic patients with supernumerary tooth. MATERIALS AND METHODS: Fifty-three patients with supernumerary tooth were identified retrospectively from 1,275 radiographic reviews who attended the Hospital Universiti Sains Malaysia (USM) Dental Clinic. Informed consent was obtained from the patients prior to the study. Blood samples were collected from 41 patients and DNA extractions were performed out of which 10 samples were chosen randomly for PCR amplification using designated primers for RUNX2 followed by DNA sequencing analysis. RESULTS: This study involved 28 male patients (68.3%) and 13 female patients (31.7%) with a gender ratio of 2.2:1 and mean age of 15.9 ± 6.2 years. DNA extraction yielded ~ 40 ng/µl of concentrated DNA, and each DNA sample had more than 1500 bp of DNA length. The purity ranged between 1.8 and 2.0. DNA sequencing analysis did not reveal any mutations in exons 5 and 6 of RUNX2. CONCLUSION: This study did not reveal any mutations in exons 5 and 6 of RUNX2 in non-syndromic patients with supernumerary tooth. CLINICAL RELEVANCE: Analysis of mutations in RUNX2 is important to enhance the understanding of tooth development in humans.

Molecular Detection of Alpha Thalassemia: A Review of Prevalent Techniques.

Alpha thalassemia (α-thalassemia) is an autosomal recessive disorder due to the reduction or absence of α globin chain production. Laboratory diagnosis of α-thalassemia requires molecular analysis for the confirmatory diagnosis. A screening test, comprising complete blood count, blood smear and hemoglobin quantification by high performance liquid chromatography and capillary electrophoresis, may not possibly detect all the thalassemia diseases. This review focused on the molecular techniques used to detect α-thalassemia, and the advantages and disadvantages of each technique were highlighted. Multiplex gap-polymerase chain reaction, single-tube multiplex polymerase chain reaction, multiplex ligation-dependent probe amplification, and loop-mediated isothermal amplification were used to detect common deletion of α-thalassemia. Furthermore, the reverse dot blot analysis and a single tube multiplex polymerase chain reaction could detect non-deletion mutation of the α-globin gene. Sanger sequencing is widely used to detect non-deletion mutations of α-thalassemia. Recently, next-generation sequencing was introduced in the diagnosis of both deletion and point mutations of α-thalassemia. Despite the advantages and disadvantages of different techniques, the routine method employed in the laboratory should be based on the facility, expertise, available equipment, and economic conditions.

Expression of Odontogenic and Osteogenic Markers in DPSCs and SHED: A Review.

The odontogenic and osteogenic potential of dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous tooth (SHED) have been shown clearly by various in vitro and in vivo studies. The findings are promising and demonstrated that dental tissue engineering can give a new hope to the individuals suffering from tooth loss and dental diseases. The evaluation of odontogenic and osteogenic differentiation of DPSCs and SHED is commonly carried out by an illustration of the expression of varied related markers. In this review, few commonly used markers such as alkaline phosphatase (ALP), collagen type 1 (Col I), dentin matrix acid phosphoprotein 1 (DMP1), dentin sialophosphoprotein (DSPP), matrix extracellular phosphoglycoprotein (MEPE), osteocalcin (OCN), and osteopontin (OPN). DSPP, DMP1, and MEPE (odontogenic markers), which play an important role during early odontoblastic differentiation and late dentin mineralization, have been highlighted. Osteoblastic proliferation and early/late osteoblastic differentiation can be assessed by estimating the expression of Col I, ALP, OCN and OPN. Despite that, till date, there is no marker which could demonstrate for certain, the differentiation of human DPSCs and SHED towards the odontogenic and osteogenic lineage. This review suggests that SHED are noticeably different from DPSCs and exhibited higher capacity for osteogenic differentiation compared to DPSCs. On the other hand, different expression levels are shown by SHED and DPSCs with regards to the osteoblast markers for osteoblastic differentiation, where, SHED expressed higher levels of ALP, Col I and OCN compared to DPSCs.

Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test.

Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions.