Patterns of inter- and intra-group genetic diversity in the Vlax Roma as revealed by Y chromosome and mitochondrial DNA lineages

Abstract

Previous genetic studies, supported by linguistic and historical data, suggest that the European Roma, comprising a large number of socially divergent endogamous groups, may be a complex conglomerate of founder populations. The boundaries and characteristics of such founder populations and their relationship to the currently existing social stratification of the Roma have not been investigated. This study is an attempt to address the issues of common vs independent origins and the history of population fissioning in three Romani groups that are well defined and strictly endogamous relative to each other. According to linguistic classifications, these groups belong to the Vlax Roma, who account for a large proportion of the European Romani population. The analysis of mtDNA sequence variation has shown that a large proportion of maternal lineages are common to the three groups. The study of a set of Y chromosome markers of different mutability has revealed that over 70% of males belong to a single lineage that appears unique to the Roma and presents with closely related microsatellite haplotypes and MSY1 codes. The study unambiguously points to the common origins of the three Vlax groups and the recent nature of the population fissions, and provides preliminary evidence of limited genetic diversity in this young founder population. European Journal of Human Genetics (2001) 9, 97 ± 104.

Origins, admixture and founder lineages in European Roma

“…4,17 The origin of the Roma population in a specific geographical region in India was investigated through the search of identical matches of Roma haplotypes from individuals carrying this haplogroup in India. The highest probability was found in the North (P = 0.66) followed by Central India (P = 0.19), whereas the rest of regions summed up 15% (Table 2).…”

“…1,2 Based on linguistic, cultural, anthropological, and genetic evidence, the proto-Roma population is thought to have originated on the Indian subcontinent. 1,[3][4][5][6][7][8][9] Their migration routes probably encompassed Persia, Armenia, and the Balkans, with a large consensus on their arrival in Eastern Europe around a thousand years ago. Within a period of about two centuries, most Roma became sedentary in the Balkan Peninsula (Balkan Roma), in the relatively ethnically tolerant surroundings of the newly established Ottoman Empire.…”

“…16 The east-to-west genetic gradient observed in Roma populations is compatible with the postulated waves of migration within Europe. 4,7,17,18 All European Roma appear to descend from a low number of founders, and to have diverged into socially distinct endogamous groups after their arrival in Europe. 14,17,18 The Indian component of the proto-Roma ancestry was supported by the identification of disease-causing mutations described in affected subjects in India and Pakistan.…”

“…14,17,18 The Indian component of the proto-Roma ancestry was supported by the identification of disease-causing mutations described in affected subjects in India and Pakistan. 9,15,19,20 Furthermore, the Roma show high frequencies of the H-M69 Y-chromosome 4,17,21,22 and mitochondrial DNA (mtDNA) M5, M18, M25, and M35 haplogroups 4,7,17,[23][24][25] reported to have an Indian origin. 25,26,27 Accordingly, studies of autosomal markers identified the Northwest of India as the most probable homeland of the European Roma.…”

“…Furthermore, the small numbers and different sets of Y-STRs used in some studies, the insufficient and variable phylogenetic resolution, and the local character of the studies have prevented the reconstruction of a clear general picture. 4,22,[28][29][30] Moreover, studies that used a large number of markers were forced to reduce the phylogenetic resolution in order to compare with previous data. 21 In addition to these limitations, the information of the Roma volunteers has been restricted to their geography tracks (ie, country of the sampling) ignoring the Roma group affiliation, which might have masked their complex population history.…”