New method for surname studies of ancient patrilineal population structures, and possible application to improvement of Y-chromosome sampling

Several studies showed that surnames are good markers to infer patrilineal genetic structures of populations, both on regional and microregional scales. As a case study, the spatial patterns of the 9,929 most common surnames of the Netherlands were analyzed by a clustering method called self-organizing maps (SOMs). The resulting clusters grouped surnames with a similar geographic distribution and origin. The analysis was shown to be in agreement with already known features of Dutch surnames, such as 1) the geographic distribution of some well-known locative suffixes, 2) historical census data, 3) the distribution of foreign surnames, and 4) polyphyletic surnames. Thus, these results validate the SOM clustering of surnames, and allow for the generalization of the technique. This method can be applied as a new strategy for a better Y-chromosome sampling design in retrospective population genetics studies, since the idenfication of surnames with a defined geographic origin enables the selection of the living descendants of those families settled, centuries ago, in a given area. In other words, it becomes possible to virtually sample the population as it was when surnames started to be in use. We show that, in a given location, the descendants of those individuals who inhabited the area at the time of origin of surnames can be as low as approximately 20%. This finding suggests 1) the major role played by recent migrations that are likely to have distorted or even defaced ancient genetic patterns, and 2) that standard-designed samplings can hardly portray a reliable picture of the ancient Y-chromosome variability of European populations.     

Do surname differences mirror dialect variation?

Our focus in this paper is the analysis of surnames, which have been proven to be reliable genetic markers because in patrilineal systems they are transmitted along generations virtually unchanged, similarly to a genetic locus on the Y chromosome. We compare the distribution of surnames to the distribution of dialect pronunciations, which are clearly culturally transmitted. Because surnames, at the time of their introduction, were words subject to the same linguistic processes that otherwise result in dialect differences, one might expect their geographic distribution to be correlated with dialect pronunciation differences. In this paper we concentrate on the Netherlands, an area of only 40,000 km2, where two official languages are spoken, Dutch and Frisian. We analyze 19,910 different surnames, sampled in 226 locations, and 125 different words, whose pronunciation was recorded in 252 sites. We find that, once the collinear effects of geography on both surname and cultural transmission are taken into account, there is no statistically significant association between the two, suggesting that surnames cannot be taken as a proxy for dialect variation, even though they can be safely used as a proxy for Y-chromosome genetic variation. We find the results historically and geographically insightful, hopefully leading to a deeper understanding of the role that local migrations and cultural diffusion play in surname and dialect diversity.     

Statistical resolution of ambiguous HLA typing data

High-resolution HLA typing plays a central role in many areas of immunology, such as in identifying immunogenetic risk factors for disease, in studying how the genomes of pathogens evolve in response to immune selection pressures, and also in vaccine design, where identification of HLA-restricted epitopes may be used to guide the selection of vaccine immunogens. Perhaps one of the most immediate applications is in direct medical decisions concerning the matching of stem cell transplant donors to unrelated recipients. However, high-resolution HLA typing is frequently unavailable due to its high cost or the inability to re-type historical data. In this paper, we introduce and evaluate a method for statistical, in silico refinement of ambiguous and/or low-resolution HLA data. Our method, which requires an independent, high-resolution training data set drawn from the same population as the data to be refined, uses linkage disequilibrium in HLA haplotypes as well as four-digit allele frequency data to probabilistically refine HLA typings. Central to our approach is the use of haplotype inference. We introduce new methodology to this area, improving upon the Expectation-Maximization (EM)-based approaches currently used within the HLA community. Our improvements are achieved by using a parsimonious parameterization for haplotype distributions and by smoothing the maximum likelihood (ML) solution. These improvements make it possible to scale the refinement to a larger number of alleles and loci in a more computationally efficient and stable manner. We also show how to augment our method in order to incorporate ethnicity information (as HLA allele distributions vary widely according to race/ethnicity as well as geographic area), and demonstrate the potential utility of this experimentally. A tool based on our approach is freely available for research purposes at http://microsoft.com/science.     

Portuguese migration to the Canary Islands: an analysis based on surnames

As a part of a wider analysis of population and genetic exchange between Spain and Portugal, the long-term pattern of Portuguese immigration to the Canary Islands was studied by means of the frequency of Portuguese surnames. A database of 1,995,833 individuals was obtained from the Spanish National Statistics Institute (2006). Among the 826 most frequent surnames to appear, 79 surnames of Portuguese origin were selected. The distribution of these surnames by municipalities and islands, the Fisher index of diversity, and the Lasker inter-population relationship coefficients R(ij) were considered. These coefficients were inter-correlated and correlated with other variables that could have influenced the distribution of surnames. From the observed distribution of the frequency of surnames, a non-random migration pattern conditioned by economic factors was found. The greatest diversity of surnames existed in cane cultivating areas after the first arrival of Portuguese immigrants. A later dispersion of surnames among islands was correlated with the inter-island geographic distances. In some islands the arrival of new immigrants continued due to their strategic location within the Canary archipelago. The Canary Islands reveal a high frequency and diversity of Portuguese surnames. The results also prove a heterogeneous distribution of these surnames throughout the archipelago. In contrast to the Portuguese archipelagos, some Canary localities have received immigrants continuously because of their economic importance in sugar cane cultivation and strategic geographic location on the maritime routes to Africa and America.     

Isonymy and isolation by distance in the Netherlands

The isonymy structure of the Netherlands was studied using the surname distribution of 2.4 million private telephone users selected from a 1996 commercial CD-ROM containing the names of 6.3 million users in the country. The users were distributed in 226 towns selected on a geographic basis to form an approximately regular grid throughout the Netherlands. Names of telephone users in each town were downloaded from the CD-ROM, with private users being selected for inclusion in the analysis. The shortest linear distance between several nearest neighboring towns was less than 2 km (e.g., Kampen and Ijsselmuiden, Krommen and Zaandijk, Hendrikdo and Papendrecht) and the longest distance was 326 km (Delfzijl and Oostburg ZL). The number of different surnames revealed by the analysis was 126,485. Lasker's distance, the negative value of the logarithm of isonymy between localities, was found to be significantly correlated with linear geographic distance, with r = 0.47 +/- 0.006. A dendrogram built using the matrix of isonymy distances, using the nearest neighbor-joining method, separates the Dutch towns into several clusters, most of them correlated with traditional Dutch regions. Comparisons with the results of previous analyses of the structure of other European countries are given. From the present analysis, isolation by distance emerges clearly, and it is relevant, although much weaker than in Switzerland, Austria, Italy, and Germany. The random component of inbreeding estimated from isonymy indicates a considerable degree of homogeneity in the Netherlands.     

Attitudes and usage of denture adhesives by complete denture wearers: a survey in Greece and the Netherlands

doi: 10.1111/j.1741‐2358.2011.00566.x
Attitudes and usage of denture adhesives by complete denture wearers: a survey in Greece and the Netherlands Objective: To explore whether there are differences in usage of and attitudes towards denture adhesives among patients in two countries. Background: There are no multi‐country surveys concerning usage of and attitudes towards denture adhesives from complete denture wearers. Materials and methods: The survey took place in Greece and the Netherlands with a sample of 284 and 165 consecutive complete denture wearers, respectively, by using a 9‐item prepared questionnaire. Statistical analysis relied on chi‐square test at α = 0.05. Results: In this survey, 26 and 20% of Greek and Dutch patients, respectively, had tried denture adhesive, but only 27% of them in Greece as well as in the Netherlands currently used it; 49% of the Greek and 45% of the Dutch participants rated the overall performance of adhesives as good. Between the two populations, no differences were identified in a majority of the research variables, except where 27% of Greeks answered that they did not know the existence of denture adhesives compared to none of the Dutch patients and when 90% of the Dutch contrary to 70% of Greeks reported that they did not need denture adhesives as they could manage their dentures well. Conclusion: The usage of and attitudes towards denture adhesives between the Greek and Dutch sample were similar with only two exceptions concerning the knowledge of existence and the need of using denture adhesives.     

Surnames in Bolivia: A study of the population of Bolivia through isonymy

In Bolivia, the Hispanic dual surname system is used. To describe the isonymic structure of Bolivia, the surname distribution of 12,139,448 persons registered in the 2006 census data was studied in 9 districts and 112 provinces of the nation, for a total of 23,244,064 surnames. The number of different surnames found was 174,922. Matrices of isonymic distances between the administrative units (districts and provinces) were constructed and tested for correlation with geographic distance. In the 112 provinces, isonymic distances were correlated with geographic distance (r = 0.545 ± 0.011 for Euclidean, 0.501 ± 0.012 for Nei's, and 0.556 ± 0.010 for Lasker's distance). The multiple regression of the surname effective number (α), equivalent to the allele effective number in a genetic system, was nonsignificant on latitude and longitude; however, it was highly significant and negative on altitude (r = ?0.72). Because the Andes extend from north to south in west‐central Bolivia, random inbreeding was lowest in the eastern districts, and highest in mountainous western Bolivia. Average α for the provinces was 122 ± 2; for the districts, it was 216 ± 29, and for the whole of Bolivia it was 213. The geographical distribution of α in the provinces is compatible with the settlement of subsequent groups of migrants moving from east and north toward the center and south of Bolivia. The relative frequency of indigenous surnames is correlated positively with altitude. This suggests that the country was populated by recent low‐density demic diffusion over a low‐density indigenous population. This may have been a common phenomenon in the immigration to tropical South America. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.     

Surnames in Chile: a study of the population of Chile through isonymy

In Chile, the Hispanic dual surname system is used. To describe the isonymic structure of this country, the distribution of 16,277,255 surnames of 8,178,209 persons was studied in the 15 regions, the 54 provinces, and the 346 communes of the nation. The number of different surnames found was 72,667. Effective surname number (Fisher's α) for the entire country was 309.0, the average for regions was 240.8 ± 17.6, for provinces 209.2 ± 8.9, and for communes 178.7 ± 4.7. These values display a variation of inbreeding between administrative levels in the Chilean population, which can be attributed to the 'Prefecture effect' of Nei and Imaizumi. Matrices of isonymic distances between units within administrative levels were tested for correlation with geographic distance. The correlations were highest for provinces (r = 0.630 ± 0.019 for Euclidean distance) and lowest for communes (r = 0.366 ± 0.009 for Lasker's). The geographical distribution of the first three-dimensions of the Euclidean distance matrix suggests that population diffusion may have taken place from the north of the country toward the center and south. The prevalence of European plus European-Amerindian (95.4%) over Amerindian ethnicity (4.6%, CIA World Factbook) is compatible with diffusion of Caucasian groups over a low-density area populated by indigenous groups. The significant excess of maternal over paternal indigenous surnames indicates some asymmetric mating between nonAmerindian and Amerindian Chileans. The available studies of Y-markers and mt-markers are in agreement with this asymmetry. In the present work, we investigate the Chilean population with the aim of detecting its structure through the study of isonymy (Crow and Mange,1965) in the three administrative levels of the nation, namely 15 regions, 54 provinces, and 346 communes.     

Are all tissue donors recognised? A cohort study in three Dutch hospitals

Nowadays, the demand for tissue transplantation has significantly increased. To optimize donor recruitment, the potential availability of tissue donors has to be evaluated. In 2011 we conducted a cohort study in three Dutch hospitals in the Netherlands. The potential amount of eligible tissue donors found, based on medical records in these hospitals is compared to the physician’s donation form report. In total 1,342 patient records were analysed. From these records, the donation officers considered 484 patients as a potential tissue donor (36.1 %). Despite the absence of contra-indication, the physician did not recognise 25 % (n = 123/484) of potential tissue donors. Physicians’ lack of sufficient knowledge of tissue donation was the main cause of adequately identifying tissue donors. A higher percentage of tissue donors in these Dutch hospitals should be feasible through creating awareness and education regarding tissue donation.     

Footprints of Middle Ages Kingdoms Are Still Visible in the Contemporary Surname Structure of Spain

To assess whether the present-day geographical variability of Spanish surnames mirrors historical phenomena occurred at the times of their introduction (13^th-16^th century), and to infer the possible effect of foreign immigration (about 11% of present-day) on the observed patterns of diversity, we have analyzed the frequency distribution of 33,753 unique surnames (tokens) occurring 51,419,788 times, according to the list of Spanish residents of the year 2008. Isonymy measures and surname distances have been computed for, and between, the 47 mainland Spanish provinces and compared to a numerical classification of corresponding language varieties spoken in Spain. The comparison of the two bootstrap consensus trees, representing surname and linguistic variability, suggests a similar picture; major clusters are located in the east (Aragón, Cataluña, Valencia), and in the north of the country (Asturias, Galicia, León). Remaining regions appear to be considerably homogeneous. We interpret this pattern as the long-lasting effect of the surname and linguistic normalization actively led by the Christian kingdoms of the north (Reigns of Castilla y León and Aragón) during and after the southwards reconquest (Reconquista) of the territories ruled by the Arabs from the 8^th century to the late 15^th century, that is when surnames became transmitted in a fixed way and when Castilian linguistic varieties became increasingly prestigious and spread out. The geography of contemporary surname and linguistic variability in Spain corresponds to the political geography at the end of the Middle-Ages. The synchronicity between surname adoption and the political and cultural effects of the Reconquista have permanently forged a Spanish identity that subsequent migrations, internal or external, did not deface.     

Surname distributions and their association with Y-chromosome markers in the Aleutian Islands

We examine surname distribution, origin, and association with Y-chromosome haplogroups in native communities from the Aleutian archipelago. The underlying hypothesis is that surnames and Y-chromosome haplogroups should be associated because both are paternally inherited markers. We used Lasker's coefficient of relationship through isonymy (R(ib) ) to identify the distribution of 143 surnames in the Aleutian Islands. The geographic distribution of surnames was explored both through frequency distribution and through the use of Mantel tests. Multidimensional scaling, chi-square, and Mantel tests were used to examine the relationship between surname and Y-chromosome markers. Overall, we observed that the distribution of surnames in the Aleutian archipelago is culturally driven rather than being one of paternal inheritance. Surnames follow a gradient from east to west, with high frequencies of Russian surnames found in western Aleut communities and high levels of non-Russian surnames found in eastern Aleut communities. A nonsignificant correlation (r = -0.0132; P = 0.436) was found between distance matrices based on haplogroups of the nonrecombining portion of the Y chromosome and surnames, although an association was found between non-Russian surnames and the predominantly non-Russian haplogroups (R1b, I1a, and I).     

Genetic and cultural transmission in Sicily as revealed by names and surnames

The study of names as cultural characters and of surnames, which behave like genetic markers, is useful for comparing cultural and genetic transmission. Genetic transmission has a unique vertical component, which also can be present in the transmission of cultural traits associated with a horizontal (or epidemic) component resulting from local customs or fashion. Our aims in this study are to infer genetic patterns in Sicily from surnames and names and to evaluate and compare the consequences of vertical versus horizontal transmission of cultural markers. Names and surnames of 88,383 consanguineous spouses collected in 16 dioceses of Sicily were analyzed by multivariate analysis to reveal and compare the geographic clusters obtained from both sets of data. As a result, both data sets indicate a major separation between the eastern and the western region of Sicily. Also, distance matrices obtained from names are highly correlated with those from surnames. But names seem to form fewer and larger geographic clusters, whereas surnames are more greatly subdivided into smaller clusters. The most common male names present a different pattern from surnames. Vertical transmission is the cause of the similarity of the main geographic patterns of names and surnames and their correspondence with findings from geography of genes, and horizontal cultural transmission explains the major differences. Furthermore, the genetic and cultural affinities can be correlated with the historical background of Sicily.     

HLA associations in classical Hodgkin lymphoma: EBV status matters

The pathogenesis of classical Hodgkin lymphoma (cHL) involves environmental and genetic factors. To explore the role of the human leukocyte antigen (HLA) genes, we performed a case-control genotyping study in 338 Dutch cHL patients using a PCR-based sequence-specific oligonucleotide probe (SSOP) hybridization approach. The allele frequencies were compared to HLA typings of more than 6,000 controls. The age of the cHL patients varied between 13 and 81 years with a median of 35 years. Nodular sclerosis subtype was the most common subtype (87%) and EBV was detected in 25% of the cHL patients. HLA-B5 was significantly increased and HLA-DR7 significantly decreased in the total cHL patient population as compared to controls. Two class II associations were observed to be specific for the EBV- cHL population with an increase of HLA-DR2 and HLA-DR5. Allele frequencies of HLA-A1, HLA-B37 and HLA-DR10 were significantly increased in the EBV+ cHL population; these alleles are in strong linkage disequilibrium and form a common haplotype in Caucasians. The allele frequency of HLA-A2 was significantly decreased in the EBV+ cHL population. Analysis of haplotypes with a frequency of >1% revealed a significant increase of HLA-A2-B7-DR2 in EBV- cHL as compared to controls. SSOP association analysis revealed significant differences between EBV+ and EBV- cHL patients for 19 probes that discriminate between HLA-A*01 and HLA-A*02. In conclusion, the HLA-A1 and HLA-A2 antigens and not specific single nucleotide variants shared by multiple alleles are responsible for the association with EBV+ cHL. Furthermore several new protective and predisposing HLA class I and II associations for the EBV+, the EBV- and the entire cHL population were identified.     

A study of surnames in China through isonymy

The isonymy structure of 1.28 billion people registered in China's National Citizen Identity Information System was studied at the provincial, prefectural, and county administrative division levels. The isonymy was 0.026 for China as a whole. The average value of isonymy was 0.033 for the 30 provinces, 0.035 for the 334 prefectures, and 0.040 for the 2811 counties. The isonymy in China was much higher than in other countries. This finding may be partly explained by the low number of surnames in the Chinese language. Two regional features can be identified from the geographic distributions of isonymy. One feature is that the middle and lower reaches of the Yangtze River had the lowest values of isonymy at both the provincial and county levels. The second feature is that most counties with the highest values of isonymy were distributed in the provinces with high proportions of ethnic minorities. According to the dendrogram of surname distances, several clusters could be identified. Most provinces in a cluster were conterminous with one another. The one exception could be explained by demic migration called "braving the journey to the northeast of China." Isolation by distance could be detected because the correlation coefficients between Nei's distance and the geographic distances at the provincial, prefectural, and county levels were 0.64, 0.43, and 0.37, respectively. Human behaviors in Chinese history that may have caused these results have been discussed, including cultural origin, migration, residential patterns, and ethnic distribution.     

Ethnicity and biodemographic structure in the Arbëreshe of the province of Cosenza, southern Italy, in the XIX century

Cultural and environmental factors interact in determining the genetic structure of human populations. Bio-demographic investigations of ethnic minorities are able to disentangle the influences that these two components have on the evolution of the genetic structure of a population. The ethnic minority of the Arb?reshe of the province of Cosenza (Calabria, southern Italy) is analyzed in this paper and its bio-demographic structure in the early 1800s is compared with that of neighboring Italian populations. The data derive from surnames recorded in the birth registers of the 19 Arbdreshe municipalities of the province of Cosenza and in 5 non-Arb?reshe municipalities of the same province. Isonymy and repeated pairs of surnames are used to analyze the bio-demographic structure of these populations, while analysis of isonymic relationships is used to investigate the variability between populations. Higher values of marital isonymy and subdivision into subpopulations characterize the Arb?reshe populations with respect to their non-Arb?reshe neighbors. However, the high range of variability of these parameters suggests a strong influence of geographic location on the marriage pattern of each community. At the same time, cultural differences linked to group identity had a strong impact in limiting marriage exchanges between the different ethnic groups living in the province of Cosenza in the early 1800s. In fact, the analysis of isonymic relationships demonstrates that geographic location shaped kinship patterns among the Arbereshe communities, but it also shows that the non-Arb?reshe neighbors formed a clearly separate reproductive cluster.     

Population structure of rural settlements of Sakha Republic (Yakutia): surname structure

The distributions of surnames have been studied in 12 rural ethnic territorial groups of Sakha Republic (Yakutia). The populations studied are characterized by considerable accumulation of individual surnames, the surname spectra of representative of different ethnic groups living in the same area substantially overlapping. The random isonymy, migration index, surname diversity, and the surname distribution redundancy index display geographic and ethnic differences. The isonymy relationship coefficients calculated for representatives of individual ethnic groups (Yakuts, Evens, and Russians) and for total populations of the settlements studied are determined by the geographic distances between the compared populations and the intensity of migrations.     

Population structure of rural settlements of Sakha Republic (Yakutia): Surname structure

The distributions of surnames have been studied in 12 rural ethnic territorial groups of Sakha Republic (Yakutia). The populations studied are characterized by considerable accumulation of individual surnames, the surname spectra of representative of different ethnic groups living in the same area substantially overlapping. The random isonymy, migration index, surname diversity, and the surname distribution redundancy index display geographic and ethnic differences. The isonymy relationship coefficients calculated for representatives of individual ethnic groups (Yakuts, Evens, and Russians) and for total populations of the settlements studied are determined by the geographic distances between the compared populations and the intensity of migrations.     

Population structure of São Miguel Island, Azores: a surname study

The knowledge of a population structure may constitute a powerful tool for mapping genes underlying susceptibility to Mendelian and complex diseases. To obtain a better understanding of the population structure of S?o Miguel Island (Azorean Archipelago, Portugal), we carried out a surname survey using the surnames listed in the most recent telephone book (2001). We identified 1315 different surnames in a total of 27,621 subscribers. The frequency of the different surnames was used to calculate the following parameters: isonymy (I), random component of inbreeding (FST), genetic diversity according to Fisher (alpha), migration rate according to Karlin-McGregor (v) and Nei's genetic distance. Eleven localities were selected, according to population size and geographic distribution, for analysis using the above parameters. Our results show that 51% of Salga's population and 52% of Sete Cidades's population are represented by six and eight surnames, respectively. These figures demonstrate the effective isolation of these two small places, which are located at opposite ends of S?o Miguel Island. Salga, Achada, and Sete Cidades present the lowest values of Fisher's alpha, indicating less genetic diversity. In contrast, the capital, Ponta Delgada, presents the highest value of alpha (78.13), indicating more genetic diversity. Our data indicate that the clustering of the localities corresponds to the geographic features of the island, where localities close together tend to share similar surnames. In conclusion, the population of S?o Miguel is relatively homogeneous and may constitute an ideal model for genetic mapping studies.     

Population genetics of red cell and serum markers in the four Albanian communities of Molise, Italy

In this paper phenotype and gene frequencies of ten genetic markers (AK, AP, EsD, 6-PGD, PGM1, PGM2, Hb, Alb, Cp and Hp) of the four Albanian communities (Campomarino, Montecilfone, Portocannone and Ururi) living in Molise are reported. The gene frequencies show a high variability. The heterogeneity analysis among these villages could demonstrate significant differences between Campomarino and Montecilfone and between Campomarino and Ururi. It is interesting to note that the demographic analysis has shown the highest rate of immigration and the lowest percentages of endogamy, Albanian surnames and Albanian-speaking individuals in Campomarino. Against that Montecilfone and Ururi are showing opposite values for the same parameters. The genetic data are also indicating some differences between these Albanian communities and the Italian population. A comparison with the present population of Albany is not possible because of the lack of data.