North African Berber and Arab influences in the western Mediterranean revealed by Y-chromosome DNA haplotypes

We have analyzed Y-chromosome diversity in the western Mediterranean area, examining p49a,f TaqI haplotype V and subhaplotypes Vb (Berber) and Va (Arab). A total of 2,196 unrelated DNA samples, belonging to 22 populations from North Africa and the southern Mediterranean coast of occidental Europe, have been typed. Subhaplotype Vb, predominant in a Berber population of Morocco (63.5%), was also found at high frequencies in southern Portugal (35.9%) and Andalusia (25.4%). The Arab subhaplotype Va, predominant in Algeria (53.9%) and Tunisia (50.6%), was also found at a relatively high frequency in Sicily (23.1%) and Naples (16.4%); its highest frequency in Iberia was in northern Portugal (22.8%) and Andalusia (15.5%). In Iberia there is a gradient of decreasing frequencies in latitude for both subhaplotypes Va and Vb, related to eight centuries of Muslim domination (8th to 15th centuries) in southern Iberia.     

Y-chromosome DNA haplotypes in north African populations

The frequency distribution of Y-chromosome haplotypes at DNA polymorphism p49/TaqI was studied in a sample of 505 North Africans from Mauritania, Morocco, Algeria, Tunisia, Libya, and Egypt. A particularly high frequency (55.0%) of Y-haplotype 5 (A2, C0, D0, F1, I1) was observed in these populations, with a relative predominance in those of Berber origin. Examination of the relative frequencies of other haplotypes in these populations, mainly haplotype 4 (the "African" haplotype), haplotype 15 (the "European" haplotype), and haplotypes 7 and 8 (the "Near-East" haplotypes), permit useful comparisons with neighboring peoples living in sub-Saharan Africa, Europe, and the Near East.     

Time to the most recent common ancestor and divergence times of populations of common chaffinches (Fringilla coelebs) in Europe and North Africa: insights into Pleistocene refugia and current levels of migration

We analyzed sequences from a 275-bp hypervariable region in the 5' end of the mitochondrial DNA control region in 190 common chaffinches (Fringilla coelebs) from 19 populations in Europe and North Africa, including new samples from Greece and Morocco. Coalescent techniques were applied to estimate the time to the most recent common ancestor (TMRCA) and divergence times of these populations. The first objective of this study was to infer the locations of refugia where chaffinches survived the last glacial episode, and this was achieved by estimating the TMRCA of populations in regions surrounding the Mediterranean that were unglaciated in the late Pleistocene. Although extant populations in Iberia, Corsica, Greece, and North Africa harbor haplotypes that are basal in a phylogenetic tree, this information alone cannot be used to infer that these localities served as refugia, because it is impossible to infer the ages of populations and their divergence times without also considering the population genetic processes of mutation, migration, and drift. Provided we assume the TMRCAs of populations are a reasonable estimate of a population's age, coalescent-based methods place resident populations in Iberia, Corsica, Greece, and North Africa during the time of the last glacial maximum, suggesting these regions served as refugia for the common chaffinch. The second objective was to determine when populations began diverging from each other and to use this as a baseline to estimate current levels of gene flow. Divergence time estimates suggest that European populations began diverging about 60,000 years before present. The relatively recent divergence of populations in North Africa, Italy, and Iberia may explain why classic migration estimates based on equilibrium assumptions are high for these populations. We compare these estimates with nonequilibrium-based estimates and show that the nonequilibrium estimates are consistently lower than the equilibrium estimates.     

Impact of mountain chains, sea straits and peripheral populations on genetic and taxonomic structure of a freshwater turtle, Mauremys leprosa (Reptilia, Testudines, Geoemydidae)

Mauremys leprosa, distributed in Iberia and North‐west Africa, contains two major clades of mtDNA haplotypes. Clade A occurs in Portugal, Spain and Morocco north of the Atlas Mountains. Clade B occurs south of the Atlas Mountains in Morocco and north of the Atlas Mountains in eastern Algeria and Tunisia. However, we recorded a single individual containing a clade B haplotype in Morocco from north of the Atlas Mountains. This could indicate gene flow between both clades. The phylogenetically most distinct clade A haplotypes are confined to Morocco, suggesting both clades originated in North Africa. Extensive diversity within clade A in south‐western Iberia argues for a glacial refuge located there. Other regions of the Iberian Peninsula, displaying distinctly lower haplotype diversities, were recolonized from within south‐western Iberia. Most populations in Portugal, Spain and northern Morocco contain the most common clade A haplotype, indicating dispersal from the south‐western Iberian refuge, gene flow across the Strait of Gibraltar, and reinvasion of Morocco by terrapins originating in south‐western Iberia. This hypothesis is consistent with demographic analyses, suggesting rapid clade A population increase while clade B is represented by stationary, fragmented populations. We recommend the eight, morphologically weakly diagnosable, subspecies of M. leprosa be reduced to two, reflecting major mtDNA clades: Mauremys l. leprosa (Iberian Peninsula and northern Morocco) and M. l. saharica (southern Morocco, eastern Algeria and Tunisia). Peripheral populations could play an important role in evolution of M. leprosa because we found endemic haplotypes in populations along the northern and southern range borders. Previous investigations in another western Palearctic freshwater turtle (Emys orbicularis) discovered similar differentiation of peripheral populations, and phylogeographies of Emys orbicularis and Mauremys rivulata underline the barrier status of mountain chains, in contrast to sea straits, suggesting common patterns for western Palearctic freshwater turtles.     

Geographical segregation in Dunlin Calidris alpina populations wintering along the East Atlantic migratory flyway – evidence from mitochondrial DNA analysis

Dunlin Calidris alpina is one of the most abundant shorebirds using coastal habitats in the East Atlantic migratory flyway, that links arctic breeding locations (Greenland to Siberia) with wintering grounds (West Europe to West Africa). Differential migration and winter segregation between populations have been indicated by morphometrics and ringing recoveries. Here, we analyse the potential of genetic markers (mitochondrial DNA – mtDNA) to validate and enhance such findings. We compared mtDNA haplotypes frequencies at different wintering sites (from north-west Europe to West Africa). All birds from West Africa had western (European) haplotypes, while the eastern (Siberian) haplotypes were only present in European winter samples, reaching higher frequencies further north in Europe. Compilation of published results from migrating birds also confirmed these differences, with the sole presence of European haplotypes in Iberia and West Africa and increasingly higher frequencies of Siberian haplotypes from south-west to north-west Europe. Comparison with published haplotype frequencies of breeding populations shows that birds from Greenland, Iceland, and North Europe were predominant in wintering grounds in West Africa, while populations wintering in West Europe originated from more eastern breeding grounds (e.g. North Russia). These results show that genetic markers can be used to enhance the integrative monitoring of wintering and breeding populations, by providing biogeographical evidence that validate the winter segregation of breeding populations.     

Las Alpujarras region (South East Spain) HLA genes study: evidence of a probable success of 17th century repopulation from North Spain

Conquest of Granada Muslim Kingdom (1492 AD) finished with Muslim occupation; they were mostly North African Berbers who had reached Iberia by 711 AD. A politics of Iberian Christianization followed after this date: Jewish were expelled in 1492 and Moriscos (Spaniards practicing Muslim religion or speaking Arab) were expelled from all Spanish territory on 1609 AD. Las Alpujarras is a southern Spain mountainous secluded region, which underwent a repopulation from North Spain and a specific Muslim (Moriscos)–Christian war took place according to historical records. Both Las Alpujarras repopulation by northern Iberians and Moriscos expulsion success have been debated and are regarded as non-clarified episodes. In this study, we have addressed the question whether the repopulation succeeded by determining HLA genes of present day Las Alpujarras inhabitants and compared with those of other Mediterranean populations HLA frequencies and genealogies. HLA frequencies show ambiguous results because of extant HLA similar gene frequencies there exist in North Africa and Spain. This is reflected by the finding of North and South western Mediterraneans close relatedness of HLA dendrograms and correspondence analyses. However, the genealogical study of extended HLA haplotypes particularly Alpujarran high frequency of HLA-A29-B44-DRB1*0701-DQA1*02-DQB1*02 (not found in Algerians but frequent in North and Central Spain) and Alpujarran low frequency extended haplotype HLA-A3-B7-DRB1*1501-DQA1*0102-DQB1*0602 (frequent in North Europe) reveals that a significant HLA gene flow from North Spain is observed in present day Alpujarrans: both haplotypes are characteristic of North Spain and North Europe, respectively. This may indicate that enforced Alpujarran repopulation from North Spain may have been a success, which was started by Spanish King Philip II in 1571 AD.     

Comparative phylogeography of two African carnivorans presumably introduced into Europe: disentangling natural versus human‐mediated dispersal across the Strait of Gibraltar

Aim Natural processes of colonization and human‐mediated introductions have shaped current patterns of biodiversity in the Mediterranean Basin. We use a comparative phylogeographic approach to investigate the genetic structure of Herpestes ichneumon and Genetta genetta (Carnivora) across the Strait of Gibraltar, and test for their supposedly contemporaneous introduction into Iberia. Location Mediterranean Basin and Africa. Methods We sequenced two mitochondrial fragments (cytochrome b and control region) of 91 (H. ichneumon) and 185 (G. genetta) individuals, including the sole archaeological record of G. genetta in Iberia, dating from the Muslim occupation. We used phylogenetic and tokogenetic methods, summary statistics, neutrality tests, geographic–genetic pairwise comparisons and coalescent estimates to explore the history of the two species in the Mediterranean Basin. Results In North Africa, an autochthonous (Clade I) and a western African mtDNA clade, coalescing in the Middle to Late Pleistocene, co‐occurred in both species. Only Clade I was present in Europe. In H. ichneumon, the European pool showed deep coalescence (median = 335 kyr) and high genetic differentiation and diversity compared with its North African counterpart, suggesting long‐term stability of female effective population size. In sharp contrast, G. genetta in Europe exhibited lower genetic diversity, weak differentiation with North Africa and recent demographic expansion; however, Andalusia and Catalonia (Spain) showed distinctly higher genetic diversity, and the archaeological specimen had the predominant European haplotype. Main conclusions The co‐occurrence of autochthonous and sub‐Saharan lineages in North Africa (1) supports a new, emerging biogeographic scenario in North Africa, and (2) suggests a connection through the Sahara, possibly from the Middle Pleistocene onwards. Our results refute the idea that H. ichneumon was introduced into Europe contemporaneously with G. genetta. Instead, they support a scenario of sweepstake dispersal during Late Pleistocene sea‐level fluctuations, followed by long‐term in situ evolution throughout the last glaciation cycles. Genetta genetta appears to have undergone a recent spread from at least two independent introduction ‘hotspots’ in Catalonia and Andalusia, possibly following antique trade routes and/or Muslim invasions. Despite their contrasting histories, the European gene pools of both species represent unusual cases leading to the preservation of autochthonous, North African lineages.     

Origin, diffusion, and differentiation of Y-chromosome haplogroups E and J: inferences on the neolithization of Europe and later migratory events in the Mediterranean area

The phylogeography of Y-chromosome haplogroups E (Hg E) and J (Hg J) was investigated in >2400 subjects from 29 populations, mainly from Europe and the Mediterranean area but also from Africa and Asia. The observed 501 Hg E and 445 Hg J samples were subtyped using 36 binary markers and eight microsatellite loci. Spatial patterns reveal that (1). the two sister clades, J-M267 and J-M172, are distributed differentially within the Near East, North Africa, and Europe; (2). J-M267 was spread by two temporally distinct migratory episodes, the most recent one probably associated with the diffusion of Arab people; (3). E-M81 is typical of Berbers, and its presence in Iberia and Sicily is due to recent gene flow from North Africa; (4). J-M172(xM12) distribution is consistent with a Levantine/Anatolian dispersal route to southeastern Europe and may reflect the spread of Anatolian farmers; and (5). E-M78 (for which microsatellite data suggest an eastern African origin) and, to a lesser extent, J-M12(M102) lineages would trace the subsequent diffusion of people from the southern Balkans to the west. A 7%-22% contribution of Y chromosomes from Greece to southern Italy was estimated by admixture analysis.     

Molecular variation at functional genes and the history of human populations--data on candidate genes for cardiovascular risk in the Mediterranean

A screening of 22 DNA polymorphisms has been performed in western Mediterranean populations (Iberian Peninsula, Morocco, and Central Mediterranean Islands). The analyzed markers correspond to polymorphic sites in several candidate genes for cardiovascular disease including apolipopoteins and their receptors (APOA1, APOB, APOE, APOC1, APOC2, LPA, and LDLR), genes implied in the hemostasis regulation (Factor VII, alpha and beta-fibrinogen, alpha and beta platelet-integrin, tissue plasminogen activator, and plasminogen activator inhibitor-1), and the angiotensin converting enzyme gene. The results are presented of a partial analysis carried out in following population samples: 6 from the Iberian Peninsula, 2 from Morocco, and 3 from Central Islands. The degree of inter-population diversity was significant and consistent with data from other kind of genetic polymorphisms. The apportionment of the allele frequency variance supported a geographic structure into three main regions: Central Mediterranean Islands, the Iberia Peninsula and North Africa. The genetic distance pattern is compatible with a south-to-north North African influence in the Iberian Peninsula and a remarkable gene flow from sub-Saharan Africa into Morocco. Epidemiologically, North Africa is characterized by high frequencies of LPA PNR alleles with high number of repeats (protective for cardiovascular risk) and high frequencies of the APOE*E4 allele (risk factor) as compared with European populations.     

Mitochondrial haplogroup H1 in north Africa: an early holocene arrival from Iberia

The Tuareg of the Fezzan region (Libya) are characterized by an extremely high frequency (61%) of haplogroup H1, a mitochondrial DNA (mtDNA) haplogroup that is common in all Western European populations. To define how and when H1 spread from Europe to North Africa up to the Central Sahara, in Fezzan, we investigated the complete mitochondrial genomes of eleven Libyan Tuareg belonging to H1. Coalescence time estimates suggest an arrival of the European H1 mtDNAs at about 8,000-9,000 years ago, while phylogenetic analyses reveal three novel H1 branches, termed H1v, H1w and H1x, which appear to be specific for North African populations, but whose frequencies can be extremely different even in relatively close Tuareg villages. Overall, these findings support the scenario of an arrival of haplogroup H1 in North Africa from Iberia at the beginning of the Holocene, as a consequence of the improvement in climate conditions after the Younger Dryas cold snap, followed by in situ formation of local H1 sub-haplogroups. This process of autochthonous differentiation continues in the Libyan Tuareg who, probably due to isolation and recent founder events, are characterized by village-specific maternal mtDNA lineages.     

Haplotypes of the Y chromosome in some populations of west Africa

One Y-specific DNA polymorphism (p49/Taql) was studied in a sample of 469 African males coming from twelve populations of sub-Saharan Africa. An high frequency (62.5%) of the Y-haplotype IV was observed in these populations, the most elevated percentage of this haplotype being observed in Mossis (from Burkina-Fasso). The “Arabic” haplotype V is present in these populations at a mean frequency of 8.7%. The “oriental” haplotype XI is present at a mean frequency of 11.3%, the most elevated percentage of this haplotype being observed in Songhaiis (from Niger). Laboratory of Pharmacogenetics     

Early Holocenic and Historic mtDNA African Signatures in the Iberian Peninsula: The Andalusian Region as a Paradigm

Determining the timing, identity and direction of migrations in the Mediterranean Basin, the role of “migratory routes” in and among regions of Africa, Europe and Asia, and the effects of sex-specific behaviors of population movements have important implications for our understanding of the present human genetic diversity. A crucial component of the Mediterranean world is its westernmost region. Clear features of transcontinental ancient contacts between North African and Iberian populations surrounding the maritime region of Gibraltar Strait have been identified from archeological data. The attempt to discern origin and dates of migration between close geographically related regions has been a challenge in the field of uniparental-based population genetics. Mitochondrial DNA (mtDNA) studies have been focused on surveying the H1, H3 and V lineages when trying to ascertain north-south migrations, and U6 and L in the opposite direction, assuming that those lineages are good proxies for the ancestry of each side of the Mediterranean. To this end, in the present work we have screened entire mtDNA sequences belonging to U6, M1 and L haplogroups in Andalusians—from Huelva and Granada provinces—and Moroccan Berbers. We present here pioneer data and interpretations on the role of NW Africa and the Iberian Peninsula regarding the time of origin, number of founders and expansion directions of these specific markers. The estimated entrance of the North African U6 lineages into Iberia at 10 ky correlates well with other L African clades, indicating that U6 and some L lineages moved together from Africa to Iberia in the Early Holocene. Still, founder analysis highlights that the high sharing of lineages between North Africa and Iberia results from a complex process continued through time, impairing simplistic interpretations. In particular, our work supports the existence of an ancient, frequently denied, bridge connecting the Maghreb and Andalusia.     

Post‐last glacial maximum expansion from Iberia to North Africa revealed by fine characterization of mtDNA H haplogroup in Tunisia

The first large‐scale fine characterization of Tunisian H lineages clarifies that the post‐Last glacial maximum expansion originating in Iberia not only led to the resettlement of Europe but also of North Africa. We found that 46% of 81 Tunisian H lineages subscreened for 1,580 bp in mtDNA coding region were affiliated with H1 and H3 subhaplogroups, which are known to have originated in Iberia. Although no signs of local expansion were detected, which would allow a clear dating of their introduction, the younger and less diverse Tunisian H1 and H3 lineages indicate Iberia as the radiating centre. Major contributions from historical migrations to this Iberian genetic imprint in Tunisia were ruled out by the mtDNA gene pool similarity between Berber/Arab/cosmopolitan samples and some “Andalusian” communities, settled by the descendents of the “Moors” who once lived in Iberia for 10 centuries (between 8th and 17th centuries), before being expelled to Tunisia. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.     

Mitochondrial DNA affinities at the Atlantic fringe of Europe

Mitochondrial DNA analysis of Atlantic European samples has detected significant latitudinal clines for several clusters with Paleolithic (H) and Neolithic (J, U4, U5a1, and U5a1a) coalescence ages in Europe. These gradients may be explained as the result of Neolithic influence on a rather homogeneous Paleolithic background. There is also evidence that some Neolithic clusters reached this border by a continental route (J, J1, J1a, U5a1, and U5a1a), whereas others (J2) did so through the Mediterranean coast. An important gene flow from Africa was detected in the Atlantic Iberia. Specific sub-Saharan lineages appeared mainly restricted to southern Portugal, and could be attributed to historic Black slave trade in the area and to a probable Saharan Neolithic influence. In fact, U6 haplotypes of specific North African origin have only been detected in the Iberian peninsula northwards from central Portugal. Based on this peculiar distribution and the high diversity pi value (0.014 +/- 0.001) in this area compared to North Africa (0.006 +/- 0.001), we reject the proposal that only historic events such as the Moslem occupation are the main cause of this gene flow, and instead propose a pre-Neolithic origin for it.     

Immunoglobulin genes in Andalusia (Spain). Genetic diversity in the Mediterranean space

Andalusia is the most densely populated region of Spain since ancient times, and has a rich history of contacts across the Mediterranean. Earlier studies have underlined the relatively high frequency of the Sub-Saharan GM 1,17 5* haplotype in western Andalusia (Huelva province, n = 252) and neighbouring Atlantic regions. Here, we provide novel data on GM/KM markers in eastern Andalusians (n = 195) from Granada province, where African GM*1,17 5* frequency is relatively high (0.044). The most frequent GM haplotypes in Andalusia parallel the most common in Europe. Altogether, these data allow us to gain insight into the genetic diversity of southern Iberia. Additionally, we assess population structure by comparing our Iberian samples with 41 Mediterranean populations. GM haplotype variation across the Mediterranean reflects intense and complex interactions between North Africans and South Europeans along human history, highlighting that African influence over the Iberian Peninsula does not follow an isotropic pattern.     

Brief communication: mtDNA variation in North Cameroon: lack of Asian lineages and implications for back migration from Asia to sub-Saharan Africa

The hypervariable region-1 and four nucleotide positions (10400, 10873, 12308, and 12705) of the coding region of mitochondrial DNA (mtDNA) were analyzed in 441 individuals belonging to eight populations (Daba, Fali, Fulbe, Mandara, Uldeme, Podokwo, Tali, and Tupuri) from North Cameroon and four populations (Bakaka, Bassa, Bamileke, and Ewondo) from South Cameroon. All mtDNAs were assigned to five haplogroups: three sub-Saharan (L1, L2, and L3), one northern African (U6), and one European (U5). Our results contrast with the observed high frequencies of a Y-chromosome haplogroup of probable Asian origin (R1*-M173) in North Cameroon. As a first step toward a better understanding of the evident discrepancy between mtDNA and Y-chromosome data, we propose two contrasting scenarios. The first one, here termed "migration and asymmetric admixture," implies a back migration from Asia to North Cameroon of a population group carrying the haplotype R1*-M173 at high frequency, and an admixture process restricted to migrant males. The second scenario, on the other hand, temed "divergent drift," implies that modern populations of North Cameroon originated from a small population group which migrated from Asia to Africa and in which, through genetic drift, Y-chromosome haplotype R1*-M173 became predominant, whereas the Asian mtDNA haplogroups were lost.     

Iberia: population genetics, anthropology, and linguistics.

Basques, Portuguese, Spaniards, and Algerians have been studied for HLA and mitochondrial DNA markers, and the data analysis suggests that pre-Neolithic gene flow into Iberia came from ancient white North Africans (Hamites). The Basque language has also been used to translate the Iberian-Tartesian language and also Etruscan and Minoan Linear A. Physical anthropometry of Iberian Mesolithic and Neolithic skeletons does not support the demic replacement in Iberia of preexisting Mesolithic people by Neolithic people bearing new farming technologies from Europe and the Middle East. Also, the presence of cardial impressed pottery in western Mediterranean Europe and across the Maghreb (North Africa) coasts at the beginning of the Neolithic provides good evidence of pre-Neolithic circum-Mediterranean contacts by sea. In addition, pre-dynastic Egyptian El-Badari culture (4,500 years ago) is similar to southern Iberian Neolithic settlements with regard to pottery and animal domestication. Taking the genetic, linguistic, anthropological, and archeological evidence together with the documented Saharan area desiccation starting about 10,000 years ago, we believe that it is possible that a genetic and cultural pre-Neolithic flow coming from southern Mediterranean coasts existed toward northern Mediterranean areas, including at least Iberia and some Mediterranean islands. This model would substitute for the demic diffusion model put forward to explain Neolithic innovations in Western Europe.     

Mammal distributions in the western Mediterranean: the role of human intervention

The natural distribution of the 17 non-flying mammal species occurring wild in both the Maghreb (north-west Africa) and Iberia (south-west Europe) is considered. It is concluded that only four species – Red Fox Vulpes vulpes, Wild Boar Sus scrofa, Wild Cat Felis silvestris and Otter Lutra lutra – are native to both regions, while another three – Red Deer Cervus elaphus, Brown Bear Ursus arctos and Aurochs Bos primigenius – were native to North Africa until the mid-Holocene but have probably died out naturally. Algerian Hedgehog Atelerix algirus, Barbary Ape Macaca sylvanus, Genet Genetta genetta and Egyptian Mongoose Herpestes ichneumon are widely accepted as introductions to Europe from North Africa. The remaining six species, and Red Deer now found in Africa, were also probably introduced – Rabbit Oryctolagus cuniculus, Weasel Mustela nivalis, Wood Mouse Apodemus sylvaticus and Lesser White-toothed Shrew Crocidura russula from Europe to Africa; Algerian Mouse Mus spretus from Africa to Europe; Savi’s Pygmy Shrew Suncus etruscus perhaps from the eastern Mediterranean to both Iberia and the Maghreb. There are two Maghrebi species which, although not found in Europe, are more closely related to Palaearctic than to Afrotropical species: Garden Dormouse Eliomys melanurus, probably native to north-west Africa, although possible augmentation of the natural population cannot be ruled out, and Whitaker’s Shrew Crocidura whitakeri, a North African endemic. Removal of so many species of European provenance from the list of mammals native to north-west Africa should not be considered to weaken its position as part of the Palaearctic zoogeographical region. Bats and other, non-mammalian, taxa illustrate the clear faunal relationship between the Maghreb and south-west Europe, whilst emphasizing its distinction from subsaharan Africa.     

Gm and Km immunoglobulin allotypes in Sicily

The aim of this study was to evaluate the intra- and inter-population variability of the Gm/Km system in the Madonie Mountains, one of the main geographical barriers in north-central Sicily. We analysed 392 samples: 145 from Alia, 128 from Valledolmo, 25 from Cerda and 94 from Palermo. Serum samples were tested for G1m (1,2,3,17), G2m (23), G3m (5,6,10,11,13,14,15,16,21,24,28) and Km (1) allotypes by the standard agglutination-inhibition method. We found the typical genetic patterns of populations in peripheral areas of the Mediterranean basin, with a high frequency of haplotypes Gm5*;3;23 and Gm5*;3;... The frequency of Gm21,28;1,17;... (about 16%) is rather high compared with other southern areas. Of great importance is the presence of the common African haplotype Gm 5*;1,17;..., ranging in frequency from 1.56% at Valledolmo to 5.5% at Alia. The presence of this haplotype suggests past contacts with peoples from North Africa. The introduction of African markers could be due to the Phoenician colonization at the end of the 2nd millennium b.c. or to the more recent Arab conquest (8th–9th centuries a.d.).     

Genetic screening of the G2019S mutation of the LRRK2 gene in Southwest European, North African, and Sephardic Jewish subjects

The G2019S mutation in exon 41 of the leucine-rich repeat kinase 2 (LRRK2) gene accounts for 3-6% of familial dominant Parkinson's disease (PD) and for 1-2% of sporadic PD. It seems that there is a north-south gradient of G2019S frequency in Europe in PD patients, and the frequency of the mutation is up to 41% in North African cases. To obtain a precise estimate of G2019S frequency in populations with relatively elevated incidence of mutation carriers, we have tested for the presence of the G2019S in the south Mediterranean countries. Three thousand one hundred healthy European subjects were compared for the G2019S incidence with 597 healthy Arab subjects originating from five populations in North Africa and with 361 healthy Sephardi Jews from five other populations. The main incidence of G2019S carriers is 1/46 in our sample of North African Arabs, the most elevated carrier incidence (1/30) being found in Moroccan Berbers. An elevated incidence (1/72) is also found in our sample of Sephardi Jews. These results contrast with the ones we found (1/1550) in a sample of 3100 healthy subjects originating from 15 populations of southern Europe. Six microsatellite markers were used in the 20 G2019S carriers we found, to conduct a haplotype analysis. Our finding on the elevated incidence of the G2019S mutation in North African Arabs and in Sephardi Jews, Berbers being the people where the mutation probably originates from, has some important consequences for future genetic diagnosis and counseling for PD in these populations.