METHODS: We conducted a 1 to N case-control study involving 300 nasopharyngeal carcinoma (NPC) cases and 533 controls matched by age, gender and ethnicity to investigate the effect of hOGG1 Ser326Cys, ITGA2 C807T and XPD Lys751Gln polymorphisms on NPC risk. Linkage disequilibrium and haplotype analysis were conducted to explore the association of allele combinations with NPC risk. Restriction fragment length polymorphism (RFLP-PCR) was used for DNA genotyping.
RESULTS: No significant association was observed between hOGG1 Ser326Cys and ITGA2 C807T polymorphisms with NPC risk after adjustment for age, gender, ethnicity, cigarette smoking, alcohol and salted fish consumption. Lys/Lys genotype of XPD Lys751Gln polymorphism was associated with increased NPC risk (OR = 1.60, 95% CI = 1.06-2.43). Subjects with history of smoking (OR = 1.81, 95% CI = 1.26-2.60), and salted fish consumption before age of 10 (OR = 1.77, 95% CI = 1.30-2.42) were observed to have increased odds of NPC. The odds of developing NPC of CGC haplotype was significantly higher compared to reference AGC haplotype (OR = 2.20, 95% CI = 1.06-4.58).
CONCLUSION: The allele combination of CGC from hOGG1, ITGA2 and XPD polymorphisms was significantly associated with increased odds of NPC.
MATERIALS AND METHODS: A total of 195 Thin Prep Pap smear samples from HPV negative and cancer free females were randomly selected as controls while 106 formalin fixed paraffin embedded samples from females with invasive cervical cancer were randomly selected for the cases group. The polymorphisms were identified using restriction fragment length polymorphism (RFLP) PCR.
RESULTS: We found no significant associations between CYP1A1 MspI polymorphism and cervical cancer in the general Malaysian female population. However, upon ethnic stratification, the variant C/C genotype was significantly associated with a 4.66-fold increase in cervical cancer risk in Malay females (95% CI= 1.21-17.9; p=0.03). No significant association was observed in the Chinese and Indian females. Additionally, there were no significant associations in the dominant model and allele frequency model analysis in both the general and ethnically stratified female population of Malaysia.
CONCLUSIONS: Our findings suggest that the C/C genotype of CYP1A1 MspI polymorphism is associated with the development of cervical carcinoma in the Malay females of Malaysia.
METHODS: Two-hundred unrelated Emirati parents of patients selected for bone marrow transplantation were genotyped for HLA class I (A, B, C) and class II (DRB1, DQB1) genes using reverse sequence specific oligonucleotide bead-based multiplexing. HLA haplotypes were assigned with certainty by segregation (pedigree) analysis, and haplotype frequencies were obtained by direct counting. HLA class I and class II frequencies in Emiratis were compared to data from other populations using standard genetic distances (SGD), Neighbor-Joining (NJ) phylogenetic dendrograms, and correspondence analysis.
RESULTS: The studied HLA loci were in Hardy-Weinberg Equilibrium. We identified 17 HLA-A, 28 HLA-B, 14 HLA-C, 13 HLA-DRB1, and 5 HLA-DQB1 alleles, of which HLA-A*02 (22.2%), -B*51 (19.5%), -C*07 (20.0%), -DRB1*03 (22.2%), and -DQB1*02 (32.8%) were the most frequent allele lineages. DRB1*03~DQB1*02 (21.2%), DRB1*16~DQB1*05 (17.3%), B*35~C*04 (11.7%), B*08~DRB1*03 (9.7%), A*02~B*51 (7.5%), and A*26~C*07~B*08~DRB1*03~DQB1*02 (4.2%) were the most frequent two- and five-locus HLA haplotypes. Correspondence analysis and dendrograms showed that Emiratis were clustered with the Arabian Peninsula populations (Saudis, Omanis and Kuwaitis), West Mediterranean populations (North Africans, Iberians) and Pakistanis, but were distant from East Mediterranean (Turks, Albanians, Greek), Levantine (Syrians, Palestinians, Lebanese), Iranian, Iraqi Kurdish, and Sub-Saharan populations.
CONCLUSIONS: Emiratis were closely related to Arabian Peninsula populations, West Mediterranean populations and Pakistanis. However, the contribution of East Mediterranean, Levantine Arab, Iranian, and Sub-Saharan populations to the Emiratis' gene pool appears to be minor.