A population genetic characterization of Estonians

This paper discusses the genetic characterization of Estonians on the basis of eight blood group systems, and the traits of PTC tasting and colour blindness in 40 Estonian population samples from various parts of the country. The allele frequencies for the total Estonian population and for the four most different regions are presented. The survey shows genetic heterogeneity within the Estonians; the greatest genetic differences were observed in West-East direction. The West-Islands, West, and North Estonia differ from the other regions (East, South-East, also South-West and Central Estonia--which form a compact cluster). The mean allele frequencies of the Estonians are comparable to those typical for populations from North and East Europe, but the allele frequencies of Estonians are characterized by tendencies in two opposite (western and eastern) directions, like in other Finno-Ugric populations and concerning other anthropological traits. Estonians reveal closest similarities to the nearest neighbouring populations, regardless of their language group. The genetic heterogeneity and antagonistic traits in Estonians seem to be traces of the original genetic structure of Finno-Ugric ancestor populations which were neither Mongoloid nor Caucasoid.     

KIR gene diversity in Mexican mestizos of San Luis Potosí

Natural killer (NK) cell function is regulated by different types of membrane-bound receptors of which killer-cell immunoglobulin-like receptors (KIRs) are the most complex and diverse. KIRs are encoded by 17 different genes located within the leukocyte receptor complex (19q13.4). The frequency with which KIR gene features are present in different human populations differs. Here, we present our results on the KIR gene diversity observed in a large group of mestizos from the central Mexican city of San Luis Potosí. In total, 53 different KIR genotypes were observed, 47 with previously described gene profiles and six harboring novel KIR gene combinations. Group A homozygous haplotypes were seen in 102 individuals (34%), while group B homozygous haplotypes were present in 45 (15%). Heterozygous combinations of groups A and B haplotypes were seen in 153 individuals (51%). Haplotype frequency estimations based on a true content of 600 chromosomes showed a relatively balanced proportion of group A (59.5%) and group B (40.5%) haplotypes in our study population. A homozygous combination of the cA01|tA01 haplotype was present in 33% of the population with other frequent combinations being cA01|tA01, cB03|tB01 in 14.7% and cA01|tA01, cB02|tA01 in 12%. The dendrogram derived from activating KIR gene phylogenetic analysis revealed five clearly distinct clades corresponding to African, East Asian, Arab/Caucasoid, Mexican mestizo/Amerindian and South Asian populations. Our results illustrate the genetic contribution that Caucasoid and Amerindian populations have made toward present-day Mexicans and suggest an important Southeast Asian genetic contribution to native Amerindian populations.     

Polymorphism of CYP1A1 and CYP2D6 genes in tundra nentses and European populations of western Siberia

Data on the first examination of the CYP1A1 and CYP2D6 genes' polymorphism in the populations of Tundra Nentsis (Yamalo-Nenetskii Autonomous District) and migrant population of Western Siberia (Novosibirsk oblast and Altaiskii krai) are presented. The frequency of the 2D6*4 mutant allele in Tundra Nentsis, characterized by a two-component Caucasoid and Mongoloid origin, was shown to be intermediate in Caucasoid and Mongoloid populations. The frequencies of the 2D6*4 and 1A1Val* mutant alleles across migrant inhabitants of Western Siberia (Caucasoid populations) were similar to that reported for the Caucasoid populations overall. Distribution of the CYP1A1 genotypes (Ile/Ile, Ile/Val*, and Val*/Val*) in Tundra Nentsis was similar to that found in Mongoloid groups. However, the frequency of the 1A1Val* allele in Tundra Nentsis was 1.5 times higher than that in the Southern Mongoloid populations (Chinese, Koreans, and Japanese).     

Genetic diversity of X-chromosome in populations of aboriginal Siberian ethnic groups: linkage disequilibrium structure and haplotype philogeography of ZFX locus

The structure of gene pool of the Siberian aboriginal population has been described based on the data on polymorphism of ZFX gene located on X-chromosome. In ten populations under study 49 haplotypes have been determined, three of which are presented with high frequency. Comparing the obtained results with the available data from HapMap project unique "African" haplotypes were revealed, which occurred in Yoruba population with the frequency of 3-7% and were not found in other populations. A coefficient of genetic differentiation of the Siberian ethnic groups under study amounted to 0.0486. Correlation analysis involving Mantel test did not reveal any significant correlations between a matrix of genetic distances and the matrices of geographic, linguistic and anthropological differences, where a maximum coefficient was obtained at the comparison with the anthropological matrix. Phylogenetic analysis proved strong isolation of African population from the other investigated ethnic groups. The Siberian populations were subdivided into two separate clusters: the first one included Yakuts, Buryats and Kets, while the second cluster included Altaians, Tuvinians and Khanty. A principal component analysis enabled to combine the investigated populations in three groups, which clearly differed by a degree of manifestation of Caucasoid and Mongoloid components. The first group included Europe inhabitants and one of Khanty populations, the second one--populations of South Siberia and China inhabitants. Mongoloid populations of East Siberia, the Japanese and Kets were combined in the third group. The results of barrier analysis revealed similar structure of genetic differentiation in the Siberian population. Linkage disequilibrium structure was obtained for six ethnic groups of Siberia. A unified linkage block by ten SNP of ZFX gene was found in five of the presented ethnic groups (excluding Ket population).     

Highland and lowland populations of Lesotho.

It has not been possible to demonstrate significant sero-genetic differences between lowland and highland Sotho populations; the differences which do exist may well be attributable to random genetic drift. The study shows that the Sotho have received an appreciable genetic contribution from the San they have absorbed but their sero-genetic profile remains eminently Negro. A low frequency of the PTC non-taster allele was found (t = 0.142 +/- 0.029) as was the overall frequency for colour blindness (cb = 0.013 +/- 0.009).     

Distribution of haptoglobin subtypes in French Basques.

THE Hl1f, Hp1s and Hp2 gene frequencies were studied in two French population samples: one from the Toulouse area and one from a Basque district. The hp alpha1F and alpha1S polypeptide chains were determined by a simple technique. The observations were in accordance with previous findings in Caucasoid populations. The frequency of the Hp1S gene was slightly higher in the Basque sample than in the group from Toulouse.     

The blood groups of the Timuri and related tribes in Afghanistan

The present investigation is a study of the blood groups of the Timuri and related tribes in Afghanistan. There is little historical documentation for the origin of the Timuri. Their name is probably a misnomer, however, since they are apparently not descended from the armies of Timur, or Tamerlane, which invaded Afghanistan during the fourteenth century. Relatively few blood group studies have been carried out on the inhabitants of Afghanistan, so detailed comparisons with other populations can be made only for the ABO system. (Certain populations in Iran to the west and a few rather widely separated populations, such as the Baltis and Nepalis to the east, have been more thoroughly investigated, and comparisons can be made with them on at least seven genetical systems.) The presence of the A₂ allele suggests gene flow from the West, but the high frequency of B is consistent with other populations tested in Afghanistan. The Rh frequencies give little critical information but the low level of cde is suggestive of Mongoloid origin. On the other hand, for the MNS system the high level of MS is typically Caucasoid. The high total M is found in Asia both in Caucasoids and Mongoloids. The presence of the Lu^a allele and the relatively high frequency of the K allele are more Caucasoid than Mongoloid, but the presence of even one Diego (Di^a) positive among the Timuri and related tribes suggests a Mongoloid contribution to the gene pool. The low frequency of P₁, though always a little suspect on travelled specimens, is consistent with this. All of the Iranian populations tested may be regarded as essentially Caucasoid from the blood group point of view. The Baltis and Nepalis show certain Mongoloid characteristics. The Timuri are distinctly more Mongoloid than the former but less so than the latter. In summary, the Timuri appear to be intermediate in allele frequencies between Caucasoid and Mongoloid populations, with unmistakable evidence of both in their ancestry.     

Frequencies of atypical serum cholinesterase among Caucasians and Negroes from southern Brazil

Frequencies of the CHE1*A allele were estimated on the basis of a sample of 999 Caucasians (1.5%) and 1,015 Negroids (0.84%) from Curitiba, Brazil. The frequency found in the Negroid subsample allows an estimate of 50 +/- 15% of Caucasoid admixture and an average gene flow in the white-black direction of the order of 5.6% per generation.     

Genetic studies among seven endogamous populations of the Koshi Zone, Bihar (India)

The distribution of AB0 and Rhesus blood groups, PTC taste sensitivity and colour blindness was studied among seven endogamous populations (Tharu, Mushar, Santal, Dhobi, Julaha, Kulhaiya and Karan Kayastha) in the Koshi Zone of Bihar (India). The phenotype and allele frequencies of the four gene loci (AB0, RH, PTC and colour blindness) show considerable differences between these populations. The measurement of genetic distances revealed, that the lowest genetic distance is seen between Dhobi and Julaha, the highest between Mushar and Tharu. From the genetic distance analysis there is some evidence for a close genetic relationship among the population groups belonging to the same region, irrespective of their caste, religion, linguistic or any other affinities. It may be concluded that all these populations have arisen through a common ancestor and changed gene frequencies among them is due to evolutionary forces like mutation, selection, migration, temporal variation and genetic drift. However, these populations retain their separate entities by practising endogamy. Gene diversity analysis reveals that these populations are at an early stage of genetic differentiation.     

Genetic Variation and Discriminating Power of Four DNA Microsatellites in the Russian Population

The allele and genotype frequency distributions of four STRs (the LPL, vWA, FES/FPS, and F13B loci) commonly used in forensic medicine were studied with a sample of 200 ethnic Russians from Siberia. Genetic and molecular diversity of the four STRs was characterized in comparison with the American Caucasoid population. The set of the four STRs showed a high power of discrimination (PD = 0.99975). Comparison of the genetic variation at the four loci revealed a considerable difference between the Russian and American Caucasoid populations, precluding the use of data on allele frequencies in American Caucasoids for forensic testing in Russia. The results can be used as a reference in Siberia.     

Different genetic components in the Ethiopian population,identified by mtDNA and Y-chromosome polymorphisms.

Seventy-seven Ethiopians were investigated for mtDNA and Y chromosome-specific variations, in order to (1) define the different maternal and paternal components of the Ethiopian gene pool, (2) infer the origins of these maternal and paternal lineages and estimate their relative contributions, and (3) obtain information about ancient populations living in Ethiopia. The mtDNA was studied for the RFLPs relative to the six classical enzymes (HpaI, BamHI, HaeII, MspI, AvaII, and HincII) that identify the African haplogroup L and the Caucasoid haplogroups I and T. The sample was also examined at restriction sites that define the other Caucasoid haplogroups (H, U, V, W, X, J, and K) and for the simultaneous presence of the DdeI10394 and AluI10397 sites, which defines the Asian haplogroup M. Four polymorphic systems were examined on the Y chromosome: the TaqI/12f2 and the 49a,f RFLPs, the Y Alu polymorphic element (DYS287), and the sY81-A/G (DYS271) polymorphism. For comparison, the last two Y polymorphisms were also examined in 87 Senegalese previously classified for the two TaqI RFLPs. Results from these markers led to the hypothesis that the Ethiopian population (1) experienced Caucasoid gene flow mainly through males, (2) contains African components ascribable to Bantu migrations and to an in situ differentiation process from an ancestral African gene pool, and (3) exhibits some Y-chromosome affinities with the Tsumkwe San (a very ancient African group). Our finding of a high (20%) frequency of the "Asian" DdeI10394AluI10397 (++) mtDNA haplotype in Ethiopia is discussed in terms of the "out of Africa" model.     

The gene pool of Belgorod oblast population: the distribution of immunological and biochemical gene markers

The frequencies of 33 alleles of 12 loci of immunological and biochemical gene markers (ABO, RH, HP, GC, TF, PI, C'3, ACP1, GLO1, PGM1, ESD, and 6-PGD) have been estimated in the indigenous Russian and Ukrainian populations of Belgorod oblast. Differences of the Belgorod population from other populations of Russia with respect to the genetic structure have been determined. It has been found that the frequency distributions of all alleles studied in the Belgorod population are similar to those typical of the genetic structure of Caucasoid populations.     

The gene pool of Belgorod oblast population: The distribution of immunological and biochemical gene markers

The frequencies of 33 alleles of 12 loci of immunological and biochemical gene markers (AB0, RH, HP, GC, TF, PI, C′3, ACP1, GLO1, PGM1, ESD, and 6-PGD) have been estimated in the indigenous Russian and Ukrainian populations of Belgorod oblast. Differences of the Belgorod population from other populations of Russia with respect to the genetic structure have been determined. It has been found that the frequency distributions of all alleles studied in the Belgorod population are similar to those typical of the genetic structure of Caucasoid populations.     

Detection of two polymorphic sites in the human c-fms gene: allele frequency and genotype in some populations of Russia

Two polymorphic sites were found in the human c-fms gene: one (G-->A) was in position 34,047 in the last intron, and the other (dinucleotide TC-->CA) was in positions 34,293 and 34,294 in the 3'-untranslated gene region, 34 bp downstream of the translation stop codon. The polymorphic dinucleotide appeared to be immediately upstream of an octamer showing 100% homology to cis element -CAAACTTC-, which is responsible for controlled instability of mRNAs of several genes. Based on these data, functional significance was assumed for this polymorphism of the c-fms gene. Allele frequencies were established for several populations. The mutant allele of the polymorphism located in the intron were detected only in one family of ethnic Germans from the Altaiskii krai. Polymorphism of the second site, which is in the 3'-untranslated region of the c-fms gene, was observed in all Caucasoid and Mongoloid populations examined. Frequency of the rare allele varied from 19.7-25% in Arctic Mongoloids to 31-42.6% in Central Asian Mongoloids and was similar in two Caucasoid populations (22.6% in ethnic Russians and 26.5% in ethnic Germans). The wide distribution of the mutant allele in human populations of the two races was considered indicative of an adaptive role of the polymorphism in providing a certain level of the gene product, a receptor, in certain cell processes.     

Sixth and seventh cusp on lower molar teeth of Icelanders

The occurrence of lower molar accessory cusps c6 and c7 is studied in three local populations of known Caucasoid origin in the Northeast of Iceland. The sample comprises 1,010 school-children, 506 boys and 504 girls. The scoring is made from dental stone casts with reference to standard plaques. Only the frequency of c6 on the second deciduous molar is relatively low as expected in a Caucasoid population. Otherwise both c6 and c7 are more common than expected, the frequencies are in fact comparable to those predicted by the Mongoloid dental complex for Mongoloid populations.     

Hemoglobin E distribution in ten endogamous population groups of Assam, India

Previous studies have reported a high incidence of hemoglobin E (HbE) in Northeast Indian populations. In the present study 10 endogamous populations of Assam belonging to two racial groups, Caucasoid and Mongoloid, were examined. The frequency of HbE gene (Hb beta E) in the Caucasoid caste populations is around 0.1, whereas the gene is highly prevalent in the Mongoloid populations, frequencies ranging between 0.2 and 0.6. Predominance of Hb beta E in the Tibeto-Burman speakers is contrary to observations made in Southeast Asia, where an association between Austro-Asiatic speakers and high prevalence of HbE exist. The highest occurrence of the gene in this area, which is on the far end of the proposed centre of distribution in Northern Kampuchea and Northeast Thailand, is also a deviation from the expected pattern of gene distribution. It is speculated that Hb beta E in the Tibeto-Burman populations of Assam arose by an independent mutation which contributed to the high frequencies of Hb beta E in the Northeast Indian populations.     

The Y Alu polymorphism in southern African populations and its relationship to other Y-specific polymorphisms.

Y-linked polymorphisms were studied in a number of African populations. The frequency of the alleles of a Y-specific Alu insertion polymorphism, termed the "Y Alu polymorphism," was determined in 889 individuals from 23 different African population groups. A trend in frequency was observed, with the insert largely absent in Caucasoid populations, at intermediate frequency in the Khoisan, and at high frequency in Negroids. The insert predates diversification of Homo sapiens, since it occurs in all groups. The Alu insertion is believed to result from a unique mutation event, and comparisons between this and several other Y-linked polymorphisms were carried out in an attempt to validate their usefulness in population and evolutionary studies. The p21A1/TaqI and pDP31/EcoRI polymorphisms and 49a/TaqI alleles were all shown to have arisen on more than one occasion, and evidence exists for a preraciation crossover event between the Y-linked pseudoautosomal XY275 locus and the Y chromosome pseudoautosomal boundary.     

Genetic relationships between Indians and their neighboring populations

Using gene frequency data for 18 protein and blood group loci, we studied the genetic relationships of four Indian subcontinent populations (peoples from Punjab, Gujarati, Andhra Pradesh, and Bangladesh) with their neighboring populations (Iranians, Afghans, Sinhalese in Sri Lanka, Nepalese, Bhutanese, Malays, Bataks in northern Sumatra, and Chinese). The results obtained indicate that the four Indian subcontinent populations and the Sinhalese are genetically closer to Iranians and Afghans (Caucasoid) than to the other neighboring Mongoloid populations. Genetic distance analysis shows a clear-cut dichotomy between the Caucasoid and Mongoloid populations.     

中国人免疫球蛋白同种异型的研究:中华民族起源的一个假说

调查了我国24个民族、74个群体的免疫球蛋白同种异型Gm、Km分布。测定了9560例个体的Gm(1,2,3,5,21)因子和9611例个体的Km(1)因子。根据Gm单体型频率计算了遗传距离并绘制了系统树。结果支持作者早前提出的有关中华民族起源于古代两个不同群体的假说。这两个群体大致以北纬30度为界,分别居栖在黄河和长江流域。本文数据和其他主要人种的Gm分布资料相比较,作者认为在人类进化中,尼格鲁人种首先和高加索-蒙古人种分离;然后高加索人种和蒙古人种分离。不同人种间的差异,大于同一人种内不同群体间的差异。蒙古人种明显地被分为南、北两大类型,分别以具有高频率的Gm~(1;21)和Gm~(1,3;5)单体型作为种族的标记。与高加索人种关联的Gm~(3;5)单体型存在于中国西北地区的少数民族中,提示混有高加索人种血缘。很可能来源于中亚地区的高加索人,通过“丝绸之路”进入中国。Km因子在所调查的74个群体中呈随机分布。     

Incidence of red-green color blindness in the Basque population

The incidence of red-green colour vision defects was studied in a sample of 392 Basque students (174 males and 218 females), using the Ishihara test cards (1987). The frequency of red-green colour blindness was 4.02 percent in the males and 0.46 percent in the females. The colour blindness frequencies found among males are within the range of other Spanish samples. Nevertheless they are lower than the values reported in other European populations.