Differences In Allele Frequencies Research Articles

Genome- and transcriptome-wide association studies of 386,000 Asian and European-ancestry women provide new insights into breast cancer genetics

By combining data from 160,500 individuals with breast cancer and 226,196 controls of Asian and European ancestry, we conducted genome- and transcriptome-wide association studies of breast cancer. We identified 222 genetic risk loci and 137 genes that were associated with breast cancer risk at a p<5.0×10-8 and a Bonferroni-corrected p<4.6×10-6, respectively. Of them, 32 loci and 15 genes showed a significantly different association between ER-positive and ER-negative breast cancer after Bonferroni correction. Significant ancestral differences in risk variant allele frequencies and their association strengths with breast cancer risk were identified. Of the significant associations identified in this study, 17 loci and 14 genes are located 1Mb away from any of the previously reported breast cancer risk variants. Pathways analyses including 221 putative risk genes identified multiple signaling pathways that may play a significant role in the development of breast cancer. Our study provides a comprehensive understanding of and new biological insights into the genetics of this common malignancy.

Strong population genomic structure of the toxic dinoflagellate Alexandrium minutum inferred from meta-transcriptome samples.

Despite theoretical expectations, marine microeukaryote population are often highly structured and the mechanisms behind such patterns remain to be elucidated. These organisms display huge census population sizes, yet genotyping usually requires clonal strains originating from single cells, hindering proper population sampling. Estimating allelic frequency directly from population wide samples, without any isolation step, offers an interesting alternative. Here, we validate the use of meta-transcriptome environmental samples to determine the population genetic structure of the dinoflagellate Alexandrium minutum. Strain and meta-transcriptome based results both indicated a strong genetic structure for A. minutum in Western Europe, to the level expected between cryptic species. The presence of numerous private alleles, and even fixed polymorphism, would indicate ancient divergence and absence of gene flow between populations. Single nucleotide polymorphisms (SNPs) displaying strong allele frequency differences were distributed throughout the genome, which might indicate pervasive selection from standing genetic variation (soft selective sweeps). However, a few genomic regions displayed extremely low diversity that could result from the fixation of adaptive de novo mutations (hard selective sweeps) within the populations.

Genetic variation of LEI0258 locus at major histocompatibility complex (MHC) region in Ethiopian indigenous village chicken

&#x0D; Indigenous chickens are locally adapted to environmental challenges and provide subsistence to millions of farmers in Africa. However, their productivity remains low compared to exotic strains. Efforts are being made to combine the local adaptation of indigenous chicken with productive traits of exotic chicken. Understanding the link between genetic diversity and environmental challenges leads to marker-assisted breed improvement programs for sustainable chicken production at smallholder level. Genetic variation at LEI0258 VNTR locus located within the MHC region has been linked to infectious disease resistance/susceptibility in commercial breeds. The aim of this study was to investigate allelic variability, genetic diversity and genetic relationships of 24 chicken populations in Ethiopia. Here, the diversity at LEI0258 in 236 chickens from 24 Ethiopian indigenous chicken populations using the major Histo-compatibility Complex linked LEI0258 marker is reported. A total of 236 DNA samples were genotyped by capillary electrophoresis from 24 chicken populations. The number of alleles, allele frequency, and heterozygosity levels were used to measure genetic variation at LEI0258 locus in Ethiopian indigenous village chicken. Twenty-nine LEI0258 alleles were observed using capillary electrophoresis that ranged from 185 to 569 bp with no significant difference in allele frequencies between populations. The number of alleles ranged from 179 (Meseret) to 569 (Batambie), with an average of 9.6 alleles per population. Allelic polymorphism was further evaluated through genotyping by Sanger sequencing. Twenty-three DNA samples with different fragment sizes were re-amplified and their alleles sequenced to depict polympormisms based on the combination of two repeat regions at 12 bp and 13 bp, respectively, and flanking regions with SNP and indels. The repeat region at 12 bp appeared 2 to 18 times, whereas the region at 13 bp appeared invariant in all populations. Sequence relationships revealed two distinct groups of alleles. The number of indels and mutations were 33 and 17, respectively. From capillary electrophoresis, the fixation coefficient of the sub-population within the total population (FST), inbreeding/fixation/ coefficient of an individual in a sub population (FIS) and total inbreeding /heterozygosity deficit/ coefficient of an individual within the total population (FIT) in the locus was 0.03, 0.08 and 0.11, respectively. Three percent of the genetic diversity was due to differences among populations, where as 8% and 89% were variations among individuals and variations within individuals, respectively. Despite the overall low genetic differentiation, both fragment and sequencing analysis revealed high allelic and genetic variability across the 24 populations. The high diversity at LEI0258 in Ethiopian indigenous village chicken populations supports the importance of the MHC region in relation to the disease challenges faced by smallholder poultry farmers across Ethiopia. We recommend that breed improvement programs ensure the maintenance of this diversity by selecting breeding stock as diverse as possible at the LEI0258 locus.

Importance of selected ABCB1 SNPs for the level of severity of depressive symptoms and effectiveness of recurrent depressive disorder therapy

The expression level of mRNA and also the function of P-gp are strictly connected with the polymorphic nature of the ABCB1 gene. In this study, we evaluated the association between promoter SNP, i.e. T-129C, three other SNPs investigated earlier and ABCB1 expression in the depression group. To assess the additive significance of these SNPs on clinicopathological features a mathematical model was also built.102 patients suffering from recurrent depressive disorder (rDD) and 94 healthy individuals from a local blood bank were enrolled in this study. ABCB1 gene polymorphism was identified by the RFLP method. The relative level of ABCB1 expression was measured by real-time PCR.For SNP T-129C no statistically significant differences in allele and genotype frequencies between depression and control groups were found (p = 0.3176). There was no statistically significant association between the expression value and 4 studied SNPs in ABCB1 (T-129C, C1236T, G2677T/A and C3435T) or the investigated clinicopathological features. Furthermore, a correlation between the initial HDRS score (lower than 23) and presence of at least 1236 T allele was observed, in particular in combination with 3435 T or 2677 T/A. Mutated allele of each SNP was also significantly associated with declined response to antidepressant therapy, both individually and in combination with others.Results of this study suggest that T-129C does not play an important role in the rDD development. The influence of the studied SNPs on ABCB1 gene expression is still unknown. However, the additive impact of 3 most frequently studied SNPs of ABCB1 on the course of depression and effectiveness of its treatment was confirmed.

Association of Nogo-A Gene Polymorphisms with Cerebral Palsy in Southern China: A Case-Control Study

Cerebral palsy (CP) is a motor and postural disorder syndrome caused by the nonprogressive dysfunction of the developing brain. Previous studies strongly indicated that the Nogo-A gene might be related to the pathogenesis of CP. The objective of this research was to explore the relationship between Nogo-A polymorphisms (rs1012603, rs12464595, and rs2864052) and CP in Southern China. The Hardy-Weinberg equilibrium (HWE) testing, allele and genotype frequencies analysis, and haplotype association analysis were applied to the genotyping of 592 CP children and 600 controls. The results showed that the allele and genotype frequencies of rs1012603 of CP group were significantly different from the control group. The haplotype “TTGGG” was significantly associated with an increased risk of CP. The allele frequencies of rs1012603 were significant differences between CP with spastic diplegia, female CP cases, and controls. Furthermore, significant differences in allele and genotype frequencies were also noticed between GMFCS I of CP and controls for rs1012603, and significant differences in allele and genotype frequencies were observed between the ADL (>9) of CP and controls for rs1012603 and rs12464595. This study showed that the SNPs rs1012603 of Nogo-A were significantly correlated with CP, and the correlations were also found in spastic diplegia, GMFCS I of CP, ADL (>9) of CP, and female subgroups, indicating that Nogo-A might mainly affect mild types of CP and there might be sex-related differences.

Association between Interleukin-6 rs1800795 Polymorphism and Serum Interleukin-6 Levels and Full-Term Neonatal Sepsis

Abstract Objective Cytokines are involved in the pathogenesis of sepsis. Association between IL-6 rs1800795 G/C polymorphism and the risks of sepsis is controversial. The aim of this study was to investigate the association of IL-6 rs1800795 G/C gene polymorphism with full-term neonatal sepsis and to determine its effect on the serum IL6 levels in these infants by a prospective study. Methods The study included 200 full-term neonates from January 2019 to December 2020: 100 with sepsis (sepsis group), 47 with culture proven sepsis, and 53 with clinical sepsis, and 100 without infection (control group). The concentrations of IL-6 in serum were determined using enzyme-linked immunosorbent assay (ELISA). The polymorphisms of IL-6 rs1800795 G/C were analyzed to compare the genotypic and allelic frequencies in the groups by using the first-generation sequencing (Sanger sequencing). The association was studied between IL-6 rs1800795 G/C polymorphisms and serum IL-6 levels, and neonatal sepsis. The relationships between IL-6 rs1800795G/C polymorphisms and sepsis and serum IL-6 levels were separately analyzed by logistic regression and analysis of variance. Results There were no significant differences in genotypic frequencies and allelic frequencies of IL-6 rs1800795(G/C) in the groups (p &gt;0.05). There were no relations between IL-6 rs1800795G/C polymorphisms and sepsis and serum IL-6 levels by statistical analysis (p &gt;0.05). Conclusion IL-6rs1800795G/C may not be genetic risk factors for full-term neonates; There was no association between serum IL-6 levels and IL-6 rs1800795G/C polymorphisms.

Elevated sdLDL level and LDLR rs688 C>T mutation are independent risk factors for ischemic stroke

PurposeTo investigate the level of sdLDL and the frequency of LDLR rs688 polymorphisms, as well as the correspondence between them, and to analyze the risk factors for stroke. MethodsBetween March 2019 and November 2019, 232 patients diagnosed with stroke and 96 health volunteers were enrolled in Quanzhou First Hospital. Subjects were divided into control group, ischemic stroke group (n=120) and hemorrhagic stroke group (n=112). The level of sdLDL and the genotypes and allele frequencies of LDLR rs688 were compared between groups, the correspondence was analyzed with Spearman method. Risk factors were analyzed with Binary logistic regression. ResultsThe level of sdLDL was highest in ischemic group, followed by hemorrhagic stroke group and lowest control group. The differences of genotypes and allele frequencies of LDLR rs688 were significant in ischemic stroke group (p=0.0000 and 0.0000 respectively), while were not significant in hemorrhagic group (p=0.184 and .0137). There was no obvious correlation between the level of sdLDL and LDLR rs688 genotype by Spearman analysis (p=0.116). ConclusionElevated sdLDL level and the C>T mutation of LDLR rs688 are independent risk factors for ischemic stroke, while they are not correlative to hemorrhagic stroke. The surveillance and regulatory of sdLDL level, the detection of LDLR rs688 gene polymorphisms may contribute to the prevention of ischemic stroke.

검도 선수군의 운동 수행능력에 영향을 미치는 유전자 다형성의 탐색

It has been widely recognized that multiple genetic as well as environmental factors contributes to the inter-individual differences of the athletic performance, and advances in genetics and genetic engineering fields allow us to search for the useful genetic markers influencing sports talents. The purpose of this study was to identify causative genes that may contribute to the athletic performance of kendo discipline. A total of 98 unrelated male individuals were participated in this study, and they divided into controls(n=43) and kendo players(n=55), respectively. Also, the genetic polymorphisms in a total of six candidate genes(AMPD1(C34T, rs17602729), MCT1(T1470A, rs1049434), BDNF(Val66Met, G/A, rs6265), DRD(-521C/T, rs1800955), AGTR2(C/A, rs11091046) and ACE2(C/T or G/A, rs1978124) genes) were genotyped by using SNaPshot method in both groups. Among genetic polymorphisms studied, there were the significant differences in both genotype and allele frequencies of the -521C/T polymorphism in DRD4 gene between both groups, respectively(p.05). Especially, the frequencies of TT genotype and T allele in this genetic polymorphism were more higher in kendo players than in controls, respectively. Therefore, it is likely that the -521C/T polymorphism in DRD4 gene may be one of genetic markers influencing athletic performance from a psychological point of view in the case of kendo players. However, sample size in this study is modest, and athletic performance is fundamentally under the influence of many genes, further studies by using larger smaple size and more candidate genes will be required in order to get a better understanding on innate talent of kendo discipline.

The genomic basis of reproductive and migratory behaviour in a polymorphic salmonid.

Recent ecotypic differentiation provides unique opportunities to investigate the genomic basis and architecture of local adaptation, while offering insights into how species form and persist. Sockeye salmon (Oncorhynchus nerka) exhibit migratory and resident ("kokanee") ecotypes, which are further distinguished into shore-spawning and stream-spawning reproductive ecotypes. Here, we analysed 36 sockeye (stream-spawning) and kokanee (stream- and shore-spawning) genomes from a system where they co-occur and have recent common ancestry (Okanagan Lake/River in British Columbia, Canada) to investigate the genomic basis of reproductive and migratory behaviour. Examination of the genomic landscape of differentiation, differences in allele frequencies and genotype-phenotype associations revealed three main blocks of sequence differentiation on chromosomes 7, 12 and 20, associated with migratory behaviour, spawning location and spawning timing. Structural variants identified in these same areas suggest they could contribute to ecotypic differentiation directly as causal variants or via maintenance of their genomic architecture through recombination suppression mechanisms. Genes in these regions were related to spatial memory and swimming endurance (SYNGAP, TPM3), as well as eye and brain development (including SIX6), potentially associated with differences in migratory behaviour and visual habitats across spawning locations, respectively. Additional genes (GREB1L, ROCK1) identified here have been associated with timing of migration in other salmonids and could explain variation in timing of O. nerka spawning. Together, these results based on the joint analysis of sequence and structural variation represent a significant advance in our understanding of the genomic landscape of ecotypic differentiation at different stages in the speciation continuum.

Genetic susceptibility of bladder cancer in the Lebanese population

BackgroundBladder cancer (BC) is the 10th most frequent tumor worldwide. Evidence shows an association between elevated risk of BC and various single nucleotide polymorphisms (SNP). BC incidence was the highest in Lebanon according to Globocan 2018 report, but little is known about the genetic susceptibility of Lebanese people to this disease. We aim to evaluate whether this prominent incidence of BC in Lebanon is attributable to known coding genetic variants.MethodsA case-control study was conducted at Hotel-Dieu de France Hospital, Beirut. A cohort of 51 Lebanese patients with BC were recruited between 2017 and 2020. Whole Exome Sequencing (WES) was performed on peripheral blood samples to detect coding genetic variants in the patients. An in-house database including WES data from 472 Lebanese individuals served as control. Literature review of the genetic predisposition to BC was conducted to establish a database of variants known to influence the risk of BC. In-common SNPs were identified between cases and the aforecited database, and their allelic frequencies was quantified in the former and in controls. Comparative analysis of the allelic frequencies of each in-common SNP was carried out between cases, controls, and the genome aggregation database (gnomAD). Analysis was performed by applying the binomial law and setting the p-value to 10− 10.Results484 polymorphisms associated with BC were extracted from the literature review ;151 of which were in-common with the 206 939 variations detected by WES in our cases. Statistically significant differences (p-value < 10− 10) in allelic frequencies was seen in 11 of the 151 in-common SNPs, but none of which corresponds with a higher BC risk. Moreover, rs4986782 variant in the NAT1 gene is not associated with BC in the Lebanese population. `.ConclusionThis is the first next-generation sequencing (NGS)- based study investigating BC risk in a Lebanese cohort of 51 patients. The majority of known exonic variants in the literature were not associated with BC in our patients. Further studies with larger sample sizes are warranted to explore the association of BC in our population with known non-coding genetic variants, and the remainder of WES-generated private Lebanese variants.

Investigating the Association of Poly (ADP-Ribose) Polymerase-1 (PARP-1) and Nuclear Factor-κB (NF-κB) Polymorphisms with Vitiligo Susceptibility

Background: Poly (ADP-ribose) polymerase-1 (PARP-1) is a co-activator of nuclear factor-κB (NF-κB) and is also strongly activated by DNA damage. PARP has also been found to be associated with several autoimmune disorders. Vitiligo is a polygenic, multifactorial, acquired skin disorder caused due to loss of epidermal melanocytes. Among others, genetic and immunological factors are associated with vitiligo pathogenesis. Aim: To investigate the association of PARP1 exon 17 (rs1136410; V762A) and promoter CA microsatellite repeat (rs1136410) polymorphisms, and NF-κB promoter -94 indelATTG (rs28362491) polymorphism with vitiligo pathogenesis in Gujarat population. Methods: Genotyping of PARP1 17T/C (rs5030870) polymorphism was done by PCR-RFLP.PARP1 CA microsatellite and NF-κB-94 indel (rs28362491) polymorphisms were genotyped by Real-Time PCR. Anti-PARP antibody levels were assessed by ELISA. Results: The results suggested no significant difference in allele and genotype frequencies of PARP1 17 T/C (p=0.5094 and p=0.4201, respectively), PARP1 CA microsatellite polymorphisms (p=0.9519 and p=0.9338, respectively) and NF-κB-94 ATTG indel polymorphism (p=0.1482 and p=0.3784, respectively) in patients as compared to controls. Conclusion: This study suggests no association of PARP1 17 T/C, PARP1 CA microsatellite and NF-κB-94 ATTG indel polymorphisms with vitiligo susceptibility in Gujarat population. Additionally, anti-PARP1 antibody levels were not significantly different among patients and controls. These findings suggest the need for additional studies to explore the role of PARP1 in vitiligo pathogenesis. Keywords: Vitiligo, poly (ADP-ribose) polymerase-1(PARP-1), nuclear factor-κB (NF-κB), polymorphisms, Autoimmunity

Genomic analyses of the scorpion mud turtle (Kinosternon scorpioides) (Linnaeus, 1766) in insular and continental Colombia: Evidence for multiple conservation and taxonomic units

The turtle genus Kinosternon is widespread with at least 25 species distributed from Mexico to northern Argentina. The taxonomy of this genus is controversial and requires a full revision using both morphological and molecular approaches. In this study, we did a genomic analysis on the species Kinosternon scorpioides distributed in insular and continental Colombia in order to define conservation units. Total DNA was extracted from 24 tissue samples and RADseq genotyping analysis was done. In addition, the intron R35 was amplified and sequenced for a subset of samples. A total of 35,507 SNPs combined with 1,047 bp of the intron were used for spatiotemporal colonization pattern reconstruction and phylogenetic analyses. In addition, SNPs were used for population structure inferences and allele frequency-based analyses. Reciprocal monophyly, significant differences in allele frequencies (Fst = 0.32 - 0.78), and evidence of reproductive isolation (no admixture/geneflow), indicate long-term divergence between groups (2-8 MYA), possibly due to geographical barriers. Four Evolutionarily Significant Units (ESUs) were defined within our samples. One ESU was represented by the insular subspecies K. scorpioides albogulare, found on San Andrés island, and three ESUs were defined for the subspecies K. s. scorpioides in continental Colombia: one trans-Andean, found in northwestern Colombia (Caribbean region) and two cis-Andean, found in eastern and southeastern Colombia in the Orinoco and Amazon regions, respectively. Colonization of this species occurred from an ancestral area on South of Central America region (~ 8.43 MYA), followed by an establishing of current populations on San Andrés Island and then, in the continent. First, in the Colombian Caribbean, next, in the Orinoco, and more recently, in the Amazon. We hypothesize that the emergence of the Panamá Isthmus, as well as the final uplift of the North Eastern Andes and Vaupes Arch, were key event leading to the differentiation of these ESUs. For management and conservation purposes, each of these ESUs should be considered as a separate management unit. A full revision of the taxonomy of the genus Kinosternon is warranted.

The double-sided of human leukocyte antigen-G molecules in type 1 autoimmune hepatitis.

The immunomodulatory effects of HLA-G expression and its role in cancers, human liver infections and liver transplantation are well documented, but so far, there are only a few reports addressing autoimmune liver diseases, particularly autoimmune hepatitis (AIH).Method and materialsWe analyzed the genetic and phenotypic characteristics of HLA-G in 205 type 1 AIH patients (AIH-1) and a population of 210 healthy controls from Sardinia (Italy).ResultsAnalysis of the HLA-G locus showed no substantial differences in allele frequencies between patients and the healthy control population. The HLA-G UTR-1 haplotype was the most prevalent in both AIH-1 patients and controls (40.24% and 34.29%). Strong linkage was found between the HLA-G UTR-1 haplotype and HLA-DRB1*03:01 in AIH-1 patients but not controls (D’ = 0.92 vs D’ = 0.50 respectively; P = 1.3x10-8). Soluble HLA-G (sHLA-G) levels were significantly lower in AIH-1 patients compared to controls [13.9 (11.6 – 17.4) U/mL vs 21.3 (16.5 – 27.8) U/mL; P = 0.011]. Twenty-four patients with mild or moderate inflammatory involvement, as assessed from liver biopsy, showed much higher sHLA-G levels compared to the 28 patients with severe liver inflammation [33.5 (23.6 – 44.8) U/mL vs 8.8 (6.1 – 14.5) U/mL; P = 0.003]. Finally, immunohistochemistry analysis of 52 liver biopsies from AIH-1 patients did not show expression of HLA-G molecules in the liver parenchyma. However, a percentage of 69.2% (36/52) revealed widespread expression of HLA-G both in the cytoplasm and the membrane of plasma cells labeled with anti-HLA-G monoclonal antibodies.ConclusionThis study highlights the positive immunomodulatory effect of HLA-G molecules on the clinical course of AIH-1 and how this improvement closely correlates with plasma levels of sHLA-G. However, our results open the debate on the ambiguous role of HLA-G molecules expressed by plasma cells, which are pathognomonic features of AIH-1.

A saturated map of common genetic variants associated with human height

Common single-nucleotide polymorphisms (SNPs) are predicted to collectively explain 40–50% of phenotypic variation in human height, but identifying the specific variants and associated regions requires huge sample sizes1. Here, using data from a genome-wide association study of 5.4 million individuals of diverse ancestries, we show that 12,111 independent SNPs that are significantly associated with height account for nearly all of the common SNP-based heritability. These SNPs are clustered within 7,209 non-overlapping genomic segments with a mean size of around 90 kb, covering about 21% of the genome. The density of independent associations varies across the genome and the regions of increased density are enriched for biologically relevant genes. In out-of-sample estimation and prediction, the 12,111 SNPs (or all SNPs in the HapMap 3 panel2) account for 40% (45%) of phenotypic variance in populations of European ancestry but only around 10–20% (14–24%) in populations of other ancestries. Effect sizes, associated regions and gene prioritization are similar across ancestries, indicating that reduced prediction accuracy is likely to be explained by linkage disequilibrium and differences in allele frequency within associated regions. Finally, we show that the relevant biological pathways are detectable with smaller sample sizes than are needed to implicate causal genes and variants. Overall, this study provides a comprehensive map of specific genomic regions that contain the vast majority of common height-associated variants. Although this map is saturated for populations of European ancestry, further research is needed to achieve equivalent saturation in other ancestries.

An association study of IL2RA polymorphisms with cerebral palsy in a Chinese population

BackgroundCerebral palsy (CP), the most common physical disability of childhood, is a nonprogressive movement disorder syndrome. Eighty percent of cases are considered idiopathic without a clear cause. Evidence has shown that cytokine abnormalities are widely thought to contribute to CP.MethodsAn association between 6 SNPs (rs12244380, rs2025345, rs12722561, rs4749926, rs2104286 and rs706778) in IL2RA (interleukin 2 receptor subunit alpha) and CP was investigated using a case–control method based on 782 CP cases and 778 controls. The allele, genotype and haplotype frequencies of SNPs were assessed using the SHEsis program. Subgroup analyses based on complications and clinical subtypes were also conducted.ResultsGlobally, no differences in genotype or allele frequencies for any SNPs remained significant after Bonferroni correction between patients and controls, except rs706778, which deviated from Hardy–Weinberg equilibrium and was excluded from further analyses. However, subgroup analysis revealed a significant association of rs2025345 with spastic tetraplegia (P genotype = 0.048 after correction) and rs12722561 with CP accompanied by global developmental delay (P allele = 0.045 after correction), even after Bonferroni correction.ConclusionsThese findings indicated that genetic variations in IL2RA are significantly associated with CP susceptibility in the Chinese Han population, suggesting that IL2RA is likely involved in the pathogenesis of CP. Further investigation with a larger sample size in a multiethnic population is needed to confirm the association.

Diverse selection pressures shaping the genetic architecture of behçet disease susceptibility.

Behçet disease (BD) is a polygenic, multifactorial, multisystem inflammatory condition with unknown etiology. Global distribution of BD is geographically structured, highest prevalence observed among East Asian, Middle Eastern, and Mediterranean populations. Although adaptive selection on a few BD susceptibility loci is speculated, a thorough evolutionary analysis on the genetic architecture of BD is lacking. We aimed to understand whether increased BD risk in the human populations with high prevalence is due to past selection on BD associated genes. We performed population genetics analyses with East Asian (high BD prevalence), European (low/very low BD prevalence), and African (very low/no BD prevalence) populations. Comparison of ancestral and derived alleles’ frequencies versus their reported susceptible or protective effect on BD showed both derived and ancestral alleles are associated with increased BD risk. Variants showing higher risk to and more significant association with BD had smaller allele frequency differences, and showed less population differentiation compared to variants that showed smaller risk and less significant association with BD. Results suggest BD alleles are not unique to East Asians but are also found in other world populations at appreciable frequencies, and argue against selection favoring these variants only in populations with high BD prevalence. BD associated gene analyses showed similar evolutionary histories driven by neutral processes for many genes or balancing selection for HLA (Human Leukocyte Antigen) genes in all three populations studied. However, nucleotide diversity in several HLA region genes was much higher in East Asians suggesting selection for high nucleotide and haplotype diversity in East Asians. Recent selective sweep for genes involved in antigen recognition, peptide processing, immune and cellular differentiation regulation was observed only in East Asians. We conclude that the evolutionary processes shaping the genetic diversity in BD risk genes are diverse, and elucidating the underlying specific selection mechanisms is complex. Several of the genes examined in this study are risk factors (such as ERAP1, IL23R, HLA-G) for other inflammatory diseases. Thus, our conclusions are not only limited to BD but may have broader implications for other inflammatory diseases.

Cranial and extracranial giant cell arteritis do not exhibit differences in the IL6 -174 G/C gene polymorphism.

Since interleukin-6 (IL-6) is a pivotal proinflammatory cytokine implicated in the pathogenesis of giant cell arteritis (GCA), we aimed to determine the potential association of the functional IL6 -174 G/C polymorphism with GCA as well as if the single base change variation at the promoter region in the human IL-6 gene may account for differences in the clinical spectrum of GCA between cranial and extracranial large vessel vasculitis (LVV)-GCA. The IL6 -174 G/C polymorphism (rs1800795) was genotyped in 191 patients with biopsy-proven GCA who had typical cranial manifestations of the disease, 109 patients with extracranial LVV-GCA, without cranial ischaemic manifestations of GCA, and 877 ethnically matched unaffected controls. A comparative study was carried out between patients with cranial and extracranial LVV-GCA and controls. No significant differences in genotype and allele frequencies of IL6 -174 G/C polymorphism were found between the whole cohort of GCA patients and healthy controls. It was also the case when cranial and extracranial LVV-GCA were compared or when each of these subgroups was compared to controls. Moreover, no significant results in genotype and allele frequencies of IL6 -174 G/C polymorphism were disclosed when the whole cohort of GCA patients were stratified according to the presence of polymyalgia rheumatica, severe ischaemic manifestations, including permanent visual loss and peripheral arteriopathy, and HLA-DRB1*04:01 status. Our results show that the IL6 -174 G/C polymorphism does not influence the phenotypic expression of GCA.

Methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphisms in breast cancer: A Filipino preliminary case-control study

Single nucleotide polymorphisms (SNP) present in folate metabolic enzymes, such as methylenetetrahydrofolate reductase (MTHFR), affect DNA synthesis and methylation processes that can lead to cancer development. Several studies suggest that MTHFR SNP is associated with breast cancer risk, particularly among Asian populations. Thus, this study determined the association of MTHFR 677C>T SNP with breast cancer risk in selected Filipino population. DNA samples from breast cancer cases (n = 100) and clinically healthy controls (n = 100) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The differences in MTHFR genotype and allele frequencies were evaluated by computing for the odds ratio (OR) with a 95 % confidence interval (CI). The CT genotype (OR: 0.775, 95 % CI: 0.35–1.71, p = 0.53), T allele (OR: 0.703, 95 % CI: 0.34–1.48, p = 0.35), and presence of at least one T allele (ORCT+TT: 0.729, 95 % CI: 0.33–1.60, p = 0.43) were not associated with breast cancer risk. Based on the SNP interaction with other risk factors, no significant difference (p > 0.05) was observed for the tumor characteristics, menarche age, and menopause age. Interestingly, a decreased risk (OR: 0.342, 95 % CI: 0.14–0.84, p = 0.019) was observed for the CC genotype in individuals who consumed dietary fibers. Meanwhile, there was an increased risk for passive smokers with the CC genotype (OR: 6.31, 95 % CI: 2.68–14.9, p < 0.001). Overall, the MTHFR 677C>T was not significantly associated with breast cancer risk in a selected Filipino population. Since this study involved a relatively small number of participants, increasing the number of samples is recommended for a more conclusive test of association of MTHFR 677C>T with breast cancer risk in Filipinos.

Status of tick-borne haemoprotozoan infection in south Indian sheep in association with variation in Ovar-DRB1 gene

A study was carried out to detect Babesia and Theileria spp. in native sheep of Andhra Pradesh, south India and determine the association of Ovar-DRB1 alleles with resistance/ susceptibility to natural infection of these species using 249 blood samples collected from different breeds (Nellore breed, Gaddabolli, Vizianagaram and Macherla brown). Initial blood smear examination revealed 12.9% (32/249) prevalence of Theileia spp. Further Babesia/Theileria genus specific PCR amplified only 430 bp 18 S rRNA specific to Theileria spp. in 34.9% (87/249) of sheep samples. None of the samples yielded amplification specific for Babesia spp. Species specific differentiation of theileriosis samples revealed that 76 were found to be positive for T. luwenshuni and eleven were positive for mixed infection with T. luwenshuni and T. ovis. Age was found to be significantly (P < 0.05) associated with positivity for theileriosis being high in adult sheep, while gender, breed and zone were not associated with the disease occurrence. Amplification and characterization of Ovar-DRB1 exon 2 by PCR-RFLP from DNA samples of healthy and infected sheep generated three genotypes ‘aa’, ‘ab’ and ‘bb’ and two alleles ‘a’ and ‘b’. The overall frequency of ‘a’ and ‘b’ allele was 0.83 and 0.17 (P < 0.01) and the polymorphic information content varied from 0.22 to 0.26 among the different sheep populations. The χ2 differences of genotype and allele frequencies between different breeds was no significant (P > 0.05). Except for Gaddabolli and Nellore sheep populations the observed heterozygosity value deviated from that of the expected heterozygosity. The χ2 test of independence revealed an association (P < 0.05) between genotypes and infection status in sheep. The frequencies of sheep carrying ‘b’ allele (‘ab’ and ‘bb’ genotypes) were higher in the healthy group compared to the theileriosis sheep, which implied that there was an association between ‘b’ allele and theileriosis resistance. This is the first study demonstrating the association between Ovar-DRB1 alleles and resistance/susceptibility to theileriosis.

Abstract 28 Comparative Analysis of the Cord Blood Bank in Quebec

IntroductionIn the context of the regional diversity observed in the population of Quebec, the Héma-Québec Cord Blood Bank (HQ CBB) representation differs from that of the Héma-Québec Stem Cell Registry (HQ Registry). The Bank encourages registrants of non-European descent to promote diversity, and only collects from health centers around Montreal and Quebec cities because of proximity concerns.ObjectiveIn this study, we aimed to analyze allele frequencies in the HQ CBB to assess similarities and differences in reference to the HQ Registry.MethodsThe HQ Registry was previously typed using high-resolution genotyping. For the HQ CBB, ambiguous two-field HLA-A, -B, -C, and -DRB1 typing data were obtained from cord blood units. Statistical analyses were performed using the GENE[RATE] population analysis tools to estimate allele and haplotype frequencies by administrative region determined by registered postal codes. Hardy-Weinberg equilibrium was verified by the nested likelihood procedure. Finally, genetic distance was compared between the HQ Registry and the HQ CBB by region using Non-metric Multi-dimensional Scaling (NMDS).ResultsBecause of the small sample size in certain regions, HLA frequency was analyzed for 7 of the 17 regions within the HQ CBB with typings from 11,472 cord blood units. The HLA allele frequencies were previously assessed for the Registry, with 3,806 donors originating from 14 administrative regions. The Hardy-Weinberg equilibrium was rejected at least in relation to one locus in 3 regions (Capitale-Nationale, Montreal, and Laval), which differs from the results obtained from the Registry, in which the equilibrium was rejected only for Montreal. As in the Registry, allele frequencies in the HQ CBB varied by region but had limited overlap with the HQ Registry. Two regions (Chaudière-Appalaches and Laval) demonstrated significant differences in allele frequencies as represented in the HQ Registry versus the HQ CBB.DiscussionWe observed differences in the Quebec population representation between the HQ CBB and the HQ Registry. This probably represents selection bias related to recruitment strategies and inclusion criteria. Importantly, the complementarity of these two stem cell sources could allow for a more diverse donor pool, and this understanding could also guide the recruitment strategies.