Our results in Asian adults provides evidence for the contribution pharmacogenetics to the toxicity of high-dose MTX and plasma MTX concentrations at 48 h following treatment in patients with acute lymphoblastic leukemia or non-Hodgkin lymphoma. These results will contribute towards the effort of MTX therapy individualization.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that involves the inflammation of various organs upon deposition of immune complexes and is characterized by uncontrolled B cell hyperactivity. Despite intensive research on the etiology of the disease, the exact cause of the onset of SLE is unknown. The pathogenesis of the disease has been proposed to be associated with the imbalance of T helper type 1 (Th1) and Th2 cytokine activities. Elevated serum levels of interleukin-6 (IL-6), a Th2 cytokine with various functions in the regulation of human biological systems, are observed in SLE patients. In the present study, 100 Malaysian SLE patients and 100 controls were evaluated in order to determine the association of polymorphisms existing in the promoter region of the IL-6 gene with the onset of SLE. The homozygous G genotype was found to be significant in SLE patients (χ 2 = 33.754; P = 0.00000000625), whereas the heterozygous G/C genotype was significant in the controls (χ 2 = 25.087; P = 0.000000548). We suggest that the C allele might have a masking effect on the G allele when both alleles are present in heterozygous individuals. However, we did not observe any significant association of the homozygous C allele with the onset of SLE or with protection from the disease (χ 2 = 1.684; P = 0.194366).

In this study, we investigated the polymorphisms of the exon 1 (+49A/G), promoter sites (-1722T/C, -1661A/G, -318C/T), and 3'-untranslated region (3'-UTR) (+6230 A/G) of the CTLA-4 gene in systemic lupus erythematosus (SLE) affected patients. Polymerase chain reaction-restriction fragment length polymorphism was used to determine genotypes of these five markers in 130 SLE patients and 130 healthy controls. Of the five tested polymorphisms, there was no statistical significant difference between the genotypic and allelic frequencies of patients with SLE and controls. Hence, we propose that the CTLA-4 gene does not play a major role in the genetic susceptibility to the development of SLE in the Malaysian population.

Five types of known mutations within the C1q gene [located at C1qA-Gln186 (C >T), C1qB-Gly15 (G >A), C1qB-Arg150 (C >T), C1qC-Gly6 (G >A), and C1qC-Arg41 (C >T)] and two SNPs located at C1qA-Gly70 (G/A) and C1qC-Pro14 (T/C) were screened in a multiracial Malaysian population. One hundred thirty patients with systemic lupus erythematosus (SLE) and 130 matched healthy control subjects were genotyped using PCR-RFLP methods. We found no occurrence of the five types of mutations in either the homozygous or heterozygous form among the 260 samples studied. Statistical analysis also revealed that there were no significant associations observed in the genotype distributions and allele frequencies among the patients with SLE and healthy control subjects with both C1qA-Gly70 (G/A) and C1qC-Pro14 (T/C) SNPs. Overall, C1q deficiency was not proven as a primary causative genetic predisposition factor for SLE in the Malaysian population.

The programmed cell death 1 (PDCD1) gene encodes for the PD-1 (programmed death 1) molecule, which negatively regulates self-reactive T- and B-cells in the maintenance of peripheral tolerance. A previous report had shown the development of lupus-like phenotypes in PD-1-deficient C57BL/6 mice, was suggestive to the role of PDCD1 in predisposing to systemic lupus erythematosus (SLE). Hence, we aimed to investigate the association between PDCD1 and SLE susceptibility in the Malaysian population. A TaqMan-based real-time PCR was employed to screen for PD1.1, PD1.3, PD1.5 and PD1.6 in both SLE and healthy control groups of 200 samples each. The observed frequency for PD1.5C/C genotype was significantly higher in Indian SLE patients and Malay controls (p < 0.01). On the other hand, the PD1.5C/T genotype might predispose the Malays to SLE, but confer a protective effect among the Indians (p < 0.01). The PD1.1, PD1.3 and PD1.6 were, however, not correlated to genetic predisposition of SLE in our Malaysian population. In conclusion, PD1.5 variant was significantly associated to SLE susceptibility in our Malaysian cohort. Our failure in replicating the association between other investigated PDCD1 variants and risk of getting SLE might due to ethnic and geographic variations in the distribution of these genetic variants.

Our findings align to those reported in other studies and point towards pathways that potentially contribute toward pathogenesis in DM1. However, the currently available data is not sufficient for these miRNAs to be made DM1-specific biomarkers because they seem to be common to many muscle pathologies. Hence, they lack specificity, but reinforce the need for further exploration of DM1 biomarkers.

OBJECTIVE:The aim of this study was to investigate the association of DLG5 and SLC22A5 gene polymorphisms with the onset of Crohn's disease (CD) in a Malaysian cohort. METHODS:Genomic DNA of 80 CD patients and 100 healthy unrelated control individuals was extracted and analyzed via polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) on DLG5 (4136 C/A), DLG5_e26 and SLC22A5 (-207 G/C) genetic polymorphisms. Data obtained from the study were then subjected to statistical analysis to test for risk association. RESULTS: Significant associations of both DLG5polymorphisms with the development of CD in the Malaysian patients were observed in this study. The homozygous C genotype of the DLG5 polymorphism was significantly related to CD patients (P = 0.0023, OR = 2.5320), while the homozygous A was significant in control individuals (P = 0.0224, OR = 0.4480). In DLG5_e26 polymorphisms, we found a significant distribution of the homozygous insA genotype in CD patients (P = 0.0006, OR = 2.8916), whereas the heterozygous insA/delA genotype was significant in controls (P = 0.0007, OR = 0.3487). We hypothesized that there might be a complex interaction of both alleles, which confered a protective effect against the onset of CD. However, we did not observe any significant correlation of SLC22A5 polymorphisms with this disease. CONCLUSIONS:In our study, both polymorphisms in the DLG5 gene were found to be associated with CD patients in Malaysia. Therefore, these loci can be potentially used as susceptibility markers in the Malaysian population.

ABSTRACT. Growth factors are polypeptides that are critical for the initiation, progression, and metastasis of cancer. Most tumor cells are capable of synthesizing particular growth factors leading to constitutive pathway activation in these cells through autocrine signaling. Epidermal growth factor (EGF) is a potent mitogenic peptide that exerts direct effects on the proliferation and differentiation of tumor cells in carcinogenesis. By contrast, vascular endothelial growth factor (VEGF) is vital for the invasion and metastasis of neoplasms through the formation of new blood vessels from mature endothelial cells. In this study, we investigated the association between functional polymorphisms of both the EGF and VEGF genes and colorectal cancer (CRC) susceptibility. A total of 130 CRC patients and 212 healthy controls were recruited for this case-control study. Genotyping of genetic variants was conducted via real-time polymerase chain reaction (PCR) amplification with allelespecific TaqMan probes. None of the genotypes of the EGF +61 A>G and VEGF +936 C>T variants was significantly associated with CRC susceptibility among the Malaysian subjects evaluated (P > 0.05). The observed frequency distributions of the EGF +61 A>G polymorphism genotypes showed ethnic heterogeneity, which was not the case for the VEGF +936 C>T genotypes. In conclusion, no positive correlation between these functional polymorphisms and CRC risk was found in this Malaysian population. Studies of the EGF and VEGF genes and CRC susceptibility are scarce, and the results reported thus far differ from one population to another. Hence, more replication studies are warranted before any firm conclusions can be made.