Twenty nuclear DNA polymorphisms in a Moroccan population: a comparison with seven other human populations

A south central Moroccan sample was analyzed for 20 nuclear DNA polymorphisms (restriction fragment length polymorphisms). The population was chosen on the basis of available information on its history, making it suitable for comparisons with data from other European populations. The markers analyzed have been studied previously in several human groups from different continents, and data on African and European samples have been compared to evaluate the genetic affinity of the studied sample with other populations, especially with two Spanish groups: Basques and Andalusians. Heterozygosity levels showed intermediate values between the African and European groups and higher than those found so far in an African group for the studied markers. Genetic distances closely matched geographical relationships through neighbor-joining tree and correspondence analysis, the Moroccans being closer to the European groups than the sub-Saharan Africans included in the analysis. Allele distributions revealed specific population associations with large weight of several alleles in the differentiation of some groups. Gene flow from sub-Saharan Africa appears to be relevant in understanding the differentiation of present Moroccan populations.     

ITS-1 versus ITS-2 pyrosequencing: a comparison of fungal populations in truffle grounds

In a recent study pyrosequencing of the ribosomal internal transcribed spacer-1 (ITS-1) has validated the effectiveness of such technology in the survey of soil fungal diversity. Here we compare the two ITS regions, ITS-1 and ITS-2, of the fungal populations occurring in Tuber melanosporum/Quercus pubescens truffle grounds and sampled in two areas, one devoid of vegetation ("burned", brulé in French) where T. melanosporum fruiting bodies are usually collected, and outside the brulé. TS1F/ITS2 and ITS3/ITS4 were used respectively for the amplification of the ITS-1 and ITS-2 regions. Two amplicon libraries were built, one for inside and the other for outside. A set of 15.788 reads was obtained. After the removal of low quality sequences, 3568 and 3156 sequences were obtained from inside the brulé with the ITS-1 and ITS-2 primers respectively. The sequences obtained from outside the brulé were 4490 with the ITS-1 primers and 2432 with the ITS-2 primers. Most of the sequences obtained for both ITS fragments could be attributed to fungal organisms. The pair of primers, ITS1-F/ITS2, was more selective, producing fewer non-fungal sequences (1% inside, 3% outside), in addition to a higher number of sequences, than the pair ITS3/ITS4 (6% inside, 11% outside). Although differences are present in the taxa percentages between ITS-1 and ITS-2, both reveal that Ascomycota were the dominant fungal phylum and that their number decreased moving from inside the brulé to outside, while the number of Basidiomycota increased. Taken together, both the short ITS-1 and ITS-2 reads obtained by the high throughput 454 sequencing provide adequate information for taxon assignment and are suitable to correlate the dynamics of the fungal populations to specific environments.     

KIF1B polymorphisms associated with the risk of inflammatory demyelinating disease in Korean population

In the present study, we explored the possible association between KIF1B polymorphisms and inflammatory demyelinating disease (IDD) susceptibility. Eleven single nucleotide polymorphisms (SNPs) were selected for the present study based on the literature, as well as linkage disequilibrium, minor allele frequency, and location. The SNPs were genotyped in 178 IDD subjects consisting of 99 neuromyelitis optica subjects, 79 multiple sclerosis subjects, and 237 healthy controls (Total N = 415). We next preformed logistic analysis to validate associations between the KIF1B polymorphisms and the risk of IDD. Statistical analyses revealed that rs17396382 and ht4 were significantly associated with IDD susceptibility with odds ratios of 2.22 and 2.17 (P = 0.001 and 0.004; P ^corr  = 0.01 and 0.03, respectively). In addition, although P values for six variants (rs3748576, rs7520935, rs2275424, rs11576866, rs17411502, and rs11121552) and one haplotype (ht1) did not reach the threshold of significance after correction for multiple testing, the SNPs showed a nominal association in primary analysis (P = 0.02 ~ 0.04). Our results suggest that rs17396382 and ht4 might be involved in IDD pathogenesis.     

Multiplex pyrosequencing method to determine CYP2C9*3, VKORC1*2, and CYP4F2*3 polymorphisms simultaneously: its application to a Korean population and comparisons with other ethnic groups

Warfarin is an anticoagulant that is difficult to administer because of the wide variation in dose requirements to achieve a therapeutic effect. CYP2C9, VKROC1, and CYP4F2 play important roles in warfarin metabolism, and their genetic polymorphisms are related to the variability in dose determination. In this study we describe a new multiplex pyrosequencing method to identify CYP2C9*3 (rs1057910), VKORC1*2 (rs9923231), and CYP4F2*3 (rs2108661) simultaneously. A multiplex pyrosequencing method to simultaneously detect CYP2C9*3, VKORC1*2, and CYP4F2*3 alleles was designed. We assessed the allele frequencies of the polymorphisms in 250 Korean subjects using the multiplex pyrosequencing method. The results showed 100 % concordance between single and multiplex pyrosequencing methods, and the polymorphisms identified by pyrosequencing were also validated with the direct sequencing method. The allele frequencies of these polymorphisms in this population were as follows: 0.040 for CYP2C9*3, 0.918 for VKORC1*2, and 0.416 for CYP4F2*3. Although the allele frequencies of the CYP2C9*3 and VKROC1*2 were comparable to those in Japanese and Chinese populations, their frequencies in this Korean population differed from those in other ethnic groups; the CYP4F2*3 frequency was the highest among other ethnic populations including Chinese and Japanese populations. The pyrosequencing methods developed were rapid and reliable for detecting CYP2C9*3, VKORC1*2, and CYP4F2*3. Large ethnic differences in the frequency of these genetic polymorphisms were noted among ethnic groups. CYP4F2*3 exhibited its highest allele frequency among other ethnic populations compared to that in a Korean population.     

Replication of genetic effects of FTO polymorphisms on BMI in a Korean population

It has been newly reported in recent studies that single-nucleotide polymorphisms (SNPs) in the first intron of the FTO gene have been associated with BMI in whites. To determine whether the gene is associated with BMI in Asians also, we performed a replication study of the association of the gene with BMI in a Korean population. Two SNPs in the FTO gene (rs1421085 and rs17817449) were genotyped using the TaqMan method in a Korean population (n = 1,733). The two SNPs were then used for an association study with BMI through statistical analyses. The rs1421085 C allele (P = 0.0015, effect size = 0.0056) and rs17817449 G allele (P = 0.0019, effect size = 0.0053) were found to be significantly associated with increased BMI. Our results suggest that FTO may be one of the worldwide obesity-risk genes.     

Digital dermatoglyphics in the Basque population: univariate and multivariate comparison with other Spanish populations

We have analyzed dermatoglyphic finger patterns in a Spanish Basque population (841 males and 911 females). Bimanual and sexual comparisons have been carried out by means of contingency analysis. The results in the Basque population are compared with those of other Spanish populations, based on univariate (chi 2 contingency test and Student's t-test) and multivariate (principal components analyses) statistical methods. Bilateral distribution asymmetry and sexual dimorphism were observed in the Basque sample. The results of the chi 2 test for pattern types in males and females show statistically significant differences between the Basques and other Spanish populations, with the exception of the males from El Bierzo. Comparing populations with regard to the Pattern Intensity Index, the differences observed are much lower; therefore, this confirms what other authors have suggested regarding the limited usefulness of indexes in populational comparisons. In the Caucasian variation range of pattern types, Basques are located in the high part with regard to arches, in the low part with regard to whorls and radial loops, and in an intermediate part in relation to ulnar loops and overall pattern intensity. Results of the multivariate comparisons show which populations are more or less distant from the Basque population and which variables are significant in contributing to these population relationships.     

Association of NRG1 and AUTS2 genetic polymorphisms with Hirschsprung disease in a South Chinese population

Hirschsprung disease (HSCR) is a genetic disorder characterized by the absence of enteric ganglia. There are more than 15 genes identified as contributed to HSCR by family‐based or population‐based approaches. However, these findings were not fulfilled to explain the heritability of most sporadic cases. In this study, using 1470 HSCR and 1473 control subjects in South Chinese population, we replicated two variants in NRG1 (rs16879552, P = 1.05E‐04 and rs7835688, P = 1.19E‐07), and further clarified the two replicated SNPs were more essential for patients with short‐segment aganglionosis (SHSCR) (P = 2.37E‐05). We also tried to replicate the most prominent signal (rs7785360) in AUTS2, which was a potential susceptibility gene with HSCR. In our results, in terms of individual association, marginal effect was observed to affect the HSCR patients following recessive model (P = 0.089). Noteworthy, significant intergenic synergistic effect between rs16879552 (NRG1) and rs7785360 (AUTS2) was identified through cross‐validation by logistic regression (P = 2.45E‐03, OR = 1.53) and multifactor dimensionality reduction (MDR, P < 0.0001, OR = 1.77). Significant correlation was observed between expression of these two genes in the normal segments of the colons (P = 0.018), together with differential expression of these genes between aganglionic colonic segments and normal colonic segments of the HSCR patients (P value for AUTS2 <0.0001, P value for NRG1 = 0.0243). Although functional evaluation is required, we supply new evidence for the NRG1 to HSCR and raised up a new susceptibility gene AUTS2 to a specific symptom for the disease.     

Identification of genetic polymorphisms of CYP2S1 in a Finnish Caucasian population

CYP2S1 is a recently discovered member of the cytochrome P450 (CYP) gene superfamily. Interestingly, even though the DNA sequence identifies it as the sole member of the new CYP2S family, CYP2S1 exhibits many features typical to CYP1 family members, e.g. dioxin-inducibility mediated by the aryl hydrocarbon receptor (AHR) and the aryl hydrocarbon receptor nuclear translocator (ARNT). In addition, CYP2S1 metabolises some aromatic hydrocarbons as well as cellular substances. These characteristics, together with a wide extrahepatic tissue distribution, suggest that CYP2S1 may have an important role in both exogenous and endogenous metabolism. This is the first study characterising CYP2S1 alleles and naming them with the recommended CYP allele nomenclature. We used denaturing gradient gel electrophoresis (DGGE) and direct sequencing to investigate genetic variation of CYP2S1 in 100 male Finnish Caucasians. Those exons in which variation was found were examined in subsequent 100 subjects. The coding region of all of the nine exons, as well as a 449 bp fragment of the proximal promoter region, was analysed. This systematic investigation revealed eight single nucleotide polymorphisms (SNPs), which comprise nine different variant alleles (haplotypes), in addition to the wild-type allele. Seven of the SNPs occurred in the protein-coding areas and one in the proximal 3' untranslated region (3'UTR). Two of these sequence variations (10347C > T and 13106C > T) result in non-conservative amino acid substitutions, i.e. Arg380Cys and Pro466Leu, respectively. The respective allelic variants, CYP2S1*2 ([10347C > T]) and CYP2S1*3 (13106C > T; 13255A > G]), occurred in our study population at frequencies of 0.50 and 3.75%, respectively. The most common of the variant alleles was CYP2S1*1H (23.8%), harbouring a 13255A > G substitution located in the 3'UTR.     

Tracking variability: recent anthropometric data for croatian population and comparison with other world populations

The variability that exists within the populations of individual countries and the variability that exists between the populations of different countries are both of interest in practical application. For these reasons, a comparison is made in this work between certain anthropometric variables of our sample of Croatian population and anthropometric variables that are available for other human populations in the world of the same or a similar age. The total sample was 1,372 subjects aged from 23 to 59 years old. For the purpose of comparison, data were taken from the study "International Data on Anthropometry" which provides an overview of anthropometric variables for many world populations, as well as data from Rudan's research that was carried out on Croatian population in the late seventies of the last century. Mean value, standard deviation and coefficient of variation have been calculated for every measured parameter. A comparison between the two research samples of Croatian population fairly displays up going trend, for body mass and other bodily dimensions, formed in three decades of difference. Mean value for body height in Rudan's sample is 161.0 cm, and for Bubas's sample in this research was 170.6 cm, both values state for Croatian population but with difference of more than 30 years. Human biologists use term "secular trend" to describe alterations in the measurable characteristics of a population of humans that occur over a century. Accordingly, in adult age, the rate of gain, concerning body height, is 10 to 30 mm per decade. The changes in body proportions during recent decades are less marked than those in body size, but the relationships between stature and weight within one national group have changed significantly.     

The polymorphisms of Tim-1 promoter region are associated with rheumatoid arthritis in a Korean population

It has been determined that the family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is expressed on T cells. A member of the TIM family, TIM-1, is considered to be a membrane protein associated with the development of Th2-biased immune responses and selectively expressed on Th2 cells. We previously showed that the exon 4 variations of Tim-1 are associated with susceptibility to allergic diseases, as well as autoimmune diseases such as rheumatoid arthritis (RA). In this study, we assessed the association between genotype and allele frequencies of the Tim-1 gene promoter region, in both RA patients and the controls without RA, using polymerase chain reaction-restriction fragment length polymorphism and single-base extension methods. We further investigated the relationships among the genotypes of each polymorphism and C-reactive protein or rheumatoid factor levels in RA patients. The genotype and allele frequencies of the –1637A>G polymorphism in RA patients are significantly different from those in the non-RA controls (P=0.0004 and P=0.001, respectively). Our results strongly suggest that polymorphism in the Tim-1 promoter region might be associated with susceptibility to RA.     

Genetic characteristics of 207 microsatellite markers in the Korean population and in other Asian populations

Microsatellites, short tandem repeats, are useful markers for genetic analysis because of their high frequency of occurrence over the genome, high information content due to variable repeat lengths, and ease of typing. To establish a panel of microsatellite markers useful for genetic studies of the Korean population, the allele frequencies and heterozygosities of 207 microsatellite markers in 119 unrelated Korean, Indian and Pakistani individuals were compared. The average heterozygosity of the Korean population was 0.71, similar to that of the Indian and Pakistani populations. More than 80% of the markers showed heterozygosity of over 0.6 and were valuable as genetic markers for genome-wide screening for disease susceptibility loci in these populations. To identify the allelic distributions of the multilocus genetic data from these microsatellite markers, the population structures were assessed by clustering. These markers supported, with the most probability, three clustering groups corresponding to the three geographical populations. When we assumed only two hypothetical clusters (K), the Korean population was separate from the others, suggesting a relatively deep divergence of the Korean population. The present 207 microsatellite markers appear to reflect the historical and geographical origins of the different populations as well as displaying a similar degree of variation to that seen in previously published genetic data. Thus, these markers will be useful as a reference for human genetic studies on Asians.     

No association of TF gene polymorphisms with hepatitis B virus Clearance and hepatocellular carcinoma occurrence in a Korean population

Development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). The transferrin (TF) gene encodes a blood plasma protein that delivers iron ion in the body. The iron uptake level has been shown to be different in HCC tumor regions, indicating a possible association between iron uptake level and HCC. To investigate whether genetic polymorphisms of TF are related with HBV clearance and/or HCC occurrence, we sequenced genomes of 24 individuals and detected 37 variants. Subsequently, eight single nucleotide polymorphisms (SNPs) in TF including 4 in the promoter region, 1 in 5′UTR and 3 in coding regions were selected and genotyped in 1,101 Korean subjects including 428 spontaneously recovered (SR) patients as controls and 673 chronic carriers (CC) as cases. Results of logistic analyses adjusted for age and gender, however, revealed no significant associations of polymorphisms and haplotypes in the TF gene with HBV clearance and HCC occurrence (P > 0.05). Since age of HBV infection is a risk factor in progression to HCC, further Cox proportional regression analysis for age of HCC as a relative hazard was performed; but no association between TF polymorphisms and onset age of HCC was found (P > 0.05). Although TF gene polymorphisms have been previously reported to be associated with various diseases, our findings indicate that genetic variations of the TF gene do not influence HBV clearance and HCC occurrence in a Korean population.     

Association between genetic polymorphisms of Toll-like receptor 2 (TLR2) and schizophrenia in the Korean population

Immunological dysregulation has been suggested to be involved in the pathogenesis of schizophrenia. Accumulating evidences further implicate that activated inflammatory processes may be particularly relevant for the precipitation of negative and cognitive symptoms of schizophrenia. Toll-like receptor 2 (TLR2) plays an important role in innate immunity by sensing a variety of pathogens and inducing an acquired immunity. In the present study, we investigated whether the coding region of single nucleotide polymorphisms (SNPs) of the TLR2 gene was associated with schizophrenia as well as with clinical symptoms in schizophrenia patients. The study population consisted of 286 Korean schizophrenia patients and 305 Korean control subjects. The assessment of the Scale for the Assessment of Negative Symptoms was used to evaluate the negative symptoms of schizophrenia; the operational criteria checklist was used to measure general psychopathology. We selected two cSNPs [rs3804099 (Asn199Asn) and rs3804100 (Ser450Ser)] considering their heterozygosity and minor allele frequency. SNP genotyping was conducted using direct sequencing. We did not find any significant associations between SNPs and schizophrenia in the genotype and allelic frequencies. On the other hand, in the analysis of cognitive symptoms, rs3804099 showed significant differences in schizophrenia patients with poor concentration in the dominant model (TC/CC vs. TT, p = 0.0099). Also, rs3804100 showed a significant association with poor concentration in the co-dominant (TC vs. TT, p = 0.014) and the dominant models (TC/CC vs. TT, p = 0.0035). We obtained no significant support for the association of the TLR2 gene with susceptibility to schizophrenia in the Korean population. However, our results provide possibility that C allele of rs3804099 and rs3804100 may be associated with poor concentration in schizophrenia patients. Further studies with larger samples are required to confirm our results.     

A population genetic study in Finland: comparison of the Finnish- and Swedish-speaking populations.

In Finland there is a substantial but geographically limited Swedish-speaking minority (in 1980 6.3% of the total population) which originates mainly from Swedish immigrants during the years 1100-1300 AD. The admixture of this population with the neighbouring Finns was studied using more than 20 blood marker loci. The reference populations, Swedes and Finns, in spite of being part of the genetically rather uniform European populations, differ from each other genetically. These quantitative and also qualitative differences in gene frequencies are mostly due to the Finnish population possessing a number of genetic markers absent or rare in the rest of Europe. The results based on a sample of 620 individuals from the Swedish-speaking population in Finland showed a rather high degree of Finnish admixture, which was estimated to about 60%. This admixture most probably occurred at an early stage since it has reached such a high and geographically homogeneous degree.     

Some genetic erythrocyte polymorphisms in the Mbugu and other populations of the Central African Republic with an analysis of genetic distances

Phenotype and gene frequencies of four blood group polymorphisms (ABO, MNSs, Rhesus, and Duffy) as well as hemoglobin types of four populations of the Republic of Central Africa are reported. All these polymorphisms are in Hardy-Weinberg equilibrium. Regarding the four blood group polymorphisms mentioned above the genetic distances according to NEI have been computed for fifteen populations of the Central-Eastern and Central-Western areas of Africa, including the four own samples. The results of these analyses are discussed.     

Glutathione S-transferase genetic polymorphisms (GSTM1, GSTT1 and GSTO2) in three Iranian populations

Genetic polymorphisms in genes encoding glutathione S-transferases M1 (GSTM1; a member of class mu), T1 (GSTT1; a member of class theta) and O2 (GSTO2; a member of class omega) have been defined previously. Studies have revealed that there were significant differences between populations for allelic frequencies of GSTT1, GSTM1 and GSTO2 N412D polymorphisms. To get more insight into the genetic structure of Iranian populations the present study was done on Iranian Georgians living in Frydoonshahr (Isfahan province) and two Persian populations who living in Shiraz (Fars province) and Frydoonshahr. Study subjects consisted of 401 unrelated healthy individuals. From these 121 were Georgians. The remaining subjects were Persians from either Frydoonshahr (n = 34) or Shiraz (n = 246). The genetic polymorphism of GSTT1, GSTM1 and GSTO2 N412D was detected by PCR-based method. The frequency of GSTT1 null genotype in Georgian and Persians of Frydoonshahr and Shiraz was 15.7, 35.2 and 24.8%, respectively. There was significant difference between these populations for the distributions of the GSTT1 genotypes (χ² = 7.00, df = 2, P = 0.030). No significant difference was observed between these populations for polymorphisms of GSTM1 (χ² = 1.682, df = 2, P = 0.431) and GSTO N142D (χ² = 4.622, df = 4, P = 0.328). The prevalence of GSTT1 null genotype in Iranian Georgians showed significant difference with Persians and other Asian countries, but it seems to be similar with the frequency which was reported from European populations.     

CYP1A2 genetic polymorphisms and adenocarcinoma lung cancer risk in the Tunisian population

AimsIn this study, the effects of four single nucleotide polymorphisms (SNPs), ? 3860G > A, ? 2467delT, ? 739T > G and ? 163C > A, of CYP1A2 gene on lung cancer were evaluated in Tunisian population.Main methodsFour polymorphisms of CYP1A2 gene were analysed in 109 healthy smokers and in 101 lung cancer cases, including 63 with squamous cell carcinoma (SCC) and 41 with adenocarcinoma (AD). The genotyping for the SNPs ? 3860 G > A, ? 2467delT, ? 739T > G and ? 163C > A was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis.Key findingsThe results showed that smokers with CYP1A2 gene polymorphisms were associated with an increased risk for the development of lung AD. There was however no significant increased risk of developing lung SCC in smokers having CYP1A2 gene polymorphisms. An increased risk of developing AD was observed in smokers who are carriers of at least one copy of ? 3680A or ? 739G giving a significant odds ratio (OR) of 6.02 (CI = 2.91–12.9) and 3.01 (CI = 1.54–5.98), respectively.SignificanceThese genotyping data are consistent with the hypothesis that tobacco-specific-N-nitrosamines (TSN) such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are major contributors to the development of lung AD and that CYP1A2 gene product plays an important role in the metabolic activation of NNK. This study suggests that SNPs of CYP1A2 could be considered as promising biomarkers in the aetiology of lung AD in smokers.     

Associations between matrilin-1 gene polymorphisms and adolescent idiopathic scoliosis curve patterns in a Korean population

Adolescent idiopathic scoliosis (AIS) is a complex disorder with an unclear etiology and pathogenesis. In previous studies, genome-wide linkage and genetic association analyses have been carried out to find genetic factors linked with AIS. In this study, we examined whether the susceptibility to AIS is associated with MATN1 gene polymorphisms in a Korean population, which included 166 individuals with AIS and 126 controls. We found that there were no statistically significant associations between any of the MATN1-linked allele or genotype frequencies between AIS and controls. However, statistically significant associations were found at single nucleotide polymorphism (SNP) rs1065755 when comparing the curve patterns of AIS with the controls. The A allele of SNP rs1065755 was associated with a higher risk of AIS than the allele G in the genotype–phenotype (curve pattern) analysis (P = 0.029). In addition, the frequency of the A allele of SNP rs1065755 in AIS with double major curves was higher than in controls (P = 0.021, ORs = 2.56 within 95% CI = 1.12–5.83). Additionally, among the predicted common haplotypes, the frequency of the haplotype GATT (31.3%) in AIS with double major curves was higher than in controls (15.2%) (P = 0.024, ORs = 2.54 within 95% CI = 1.11–5.84). We conclude that the A allele of SNP rs1065755 in the MATN1 gene is associated with AIS.     

Multiallelic restriction fragment polymorphisms in genetic counseling: population genetic considerations

The use of selectively neutral, multiallelic molecular markers to trace the transmission of tightly linked genes is examined theoretically for all genetic counseling situations in which the diagnosis of deleterious progeny is desired. Formulae are computed in terms of the gametic frequency distribution in the population, for the expected fraction of matings (alpha i) which allow exact diagnosis on the basis of the marker alleles transmitted, assuming an arbitrary number (n) of alleles segregating at the marker locus and possibly nonrandom associations between the loci. In each case, it is shown that the diagnostic value of a multiallelic marker increases as n increases, with approximately 1-1/n matings informative, on average.     

Frequencies of four genetic polymorphisms in the CYP1A2 gene in Turkish population

Cytochrome P450 (CYP) 1A2 gene is involved in the metabolic activation of several carcinogens and altered metabolization of some clinically used drugs. We aimed to investigate the distributions of genetic polymorphisms -3860 (G/A)(CYP1A2*1C) and -2467 (T/del)(CYP1A2*1D) in the 5'-flanking region and -739 (T/G)(CYP1A2*1E) and -163(C/A)(CYP1A2*1F) in the first intron of the CYP1A2 gene in 110 unrelated healthy Turkish volunteers by PCR-RFLP technique. The frequencies of each polymorphism in Turkish population were found as 0.04, 0.92, 0.01, 0.27 for CYP1A2*1C, CYP1A2*1D, CYP1A2*1E, CYP1A2*1F, respectively. Compared with other populations, CYP1A2*1D has been found to be significantly increased in Turkish population. On the other hand, in general, the frequencies of the other polymorphisms were concordant with those in the Egyptian and Caucasian populations, and were different from those in the Japanese, Chinese and Ethiopian populations. Our results suggest that due to increased frequency of CYP1A2*1D in Turkish population, functional significance of CYP1A2*1D should be evaluated. It might be screened to determine the relationship between CYP1A2*1D and CYP1A2 related drug metabolisms in associated groups.