A new panel of SNPs to assess thyroid carcinoma risk: a pilot study in a Brazilian admixture population

The role of rs2236242 at SERPINA12 gene and vaspin level on papillary thyroid carcinoma

Several studies showed that adipokines are associated with types of cancer which are documented to be effective in cancer biology. This study aimed to determine the relationship between vaspin rs2236242 polymorphism and the vaspin level with papillary thyroid carcinoma (PTC), and multinodular goiter (MNG). In this cross-sectional study, we recruited 170 candidates. Ninety patients with newly diagnosed (PTC 60 patients and MNG 30 patients), and 80 participants as a control group referred to Shariati Hospital, Tehran, Iran, were enrolled in the study. The vaspin hormone measurements were conducted utilizing the Elisa Kit. Using Tetra amplification resistant-mutation system polymerase chain reaction (T-ARMS-PCR), the genotype of single nucleotide polymorphism (SNP) rs2236242 was determined. The statistical analysis was performed using SPSS software version 20. Our findings showed significant age and genotype frequency differences in three groups (p-value < 0.05). There was no significant difference in vaspin levels between PTC, and control groups. The level of vaspin in MNG compared to the control group had significantly different, but there were no differences after adjustment for age. Results showed the genotypes of vaspin rs2236242 polymorphism are not associated with the level of vaspin. The genotypes and allele frequencies of vaspin rs2236242 in the PTC and MNG groups were significant compared to the control group. We have found vaspin rs2236242 gene polymorphism as a potential marker of papillary thyroid cancer. The A allele of the vaspin SNP rs2236242 plays a protective role against PTC and MNG. SNP at rs2236242 was not significantly associated with vaspin levels.

Local Ancestry Adjusted Allelic Association Analysis Robustly Captures Tuberculosis Susceptibility Loci

Pulmonary tuberculosis (TB), caused by Mycobacterium tuberculosis, is a complex disease. The risk of developing active TB is in part determined by host genetic factors. Most genetic studies investigating TB susceptibility fail to replicate association signals particularly across diverse populations. South African populations arose because of multi-wave genetic admixture from the indigenous KhoeSan, Bantu-speaking Africans, Europeans, Southeast Asian-and East Asian populations. This has led to complex genetic admixture with heterogenous patterns of linkage disequilibrium and associated traits. As a result, precise estimation of both global and local ancestry is required to prevent both false positive and false-negative associations. Here, 820 individuals from South Africa were genotyped on the SNP-dense Illumina Multi-Ethnic Genotyping Array (∼1.7M SNPs) followed by local and global ancestry inference using RFMix. Local ancestry adjusted allelic association (LAAA) models were utilized owing to the extensive genetic heterogeneity present in this population. Hence, an interaction term, comprising the identification of the minor allele that corresponds to the ancestry present at the specific locus under investigation, was included as a covariate. One SNP (rs28647531) located on chromosome 4q22 was significantly associated with TB susceptibility and displayed a SNP minor allelic effect (G allele, frequency = 0.204) whilst correcting for local ancestry for Bantu-speaking African ancestry (p-value = 5.518 × 10^-7; OR = 3.065; SE = 0.224). Although no other variants passed the significant threshold, clear differences were observed between the lead variants identified for each ancestry. Furthermore, the LAAA model robustly captured the source of association signals in multi-way admixed individuals from South Africa and allowed the identification of ancestry-specific disease risk alleles associated with TB susceptibility that have previously been missed.

Polymorphisms of IL-4 and IL-4R are associated to some demographic characteristics of differentiated thyroid cancer patients but are not determinants of risk in the Brazilian population

BACKGROUND

IL-4 is known to present abnormal expression in thyroid tumors and SNPs in the IL-4 and its receptor IL-4R genes are associated to risk and mortality of various types of cancer.

METHODS

In order to evaluate their role in differentiated thyroid cancer (DTC), we investigated genetic frequencies of two IL-4 promoter SNPs (rs2070874 C>T, rs2243250 C>T) and four non-synonymous SNPs of the IL-4R gene (rs1805010 A>G, rs1805012 C>T, rs1805013 C>T, rs1801275 A>G) in 300 DTC patients matched to 300 controls. All patients were managed according to current guidelines and followed-up for a period of 12-252 months (69.20 ± 52.70 months).

RESULTS

Although none of the six investigated SNPs showed association with risk of DTC, rs1805010 was associated with age of diagnosis and the SNPs rs1805012 and rs1801275 were associated to gender. Further, in-silico analysis showed that all these three SNPs were able to cause decreased stability of the protein. We were not able to demonstrate any other association to clinical features of aggressiveness or to patients' prognosis.

CONCLUSIONS

These findings indicate that although genetic variants in IL-4 and IL-4R do not influence the risk or outcome of DTC patients, their influence on the behavior of thyroid tumors deserves further investigation.