Reconstructing the Indian Origin and Dispersal of the European Roma: A Maternal Genetic Perspective

Abstract

Previous genetic, anthropological and linguistic studies have shown that Roma (Gypsies) constitute a founder population dispersed throughout Europe whose origins might be traced to the Indian subcontinent. Linguistic and anthropological evidence point to Indo-Aryan ethnic groups from North-western India as the ancestral parental population of Roma. Recently, a strong genetic hint supporting this theory came from a study of a private mutation causing primary congenital glaucoma. In the present study, complete mitochondrial control sequences of Iberian Roma and previously published maternal lineages of other European Roma were analyzed in order to establish the genetic affinities among Roma groups, determine the degree of admixture with neighbouring populations, infer the migration routes followed since the first arrival to Europe, and survey the origin of Roma within the Indian subcontinent. Our results show that the maternal lineage composition in the Roma groups follows a pattern of different migration routes, with several founder effects, and low effective population sizes along their dispersal. Our data allowed the confirmation of a North/West migration route shared by Polish, Lithuanian and Iberian Roma. Additionally, eleven Roma founder lineages were identified and degrees of admixture with host populations were estimated. Finally, the comparison with an extensive database of Indian sequences allowed us to identify the Punjab state, in North-western India, as the putative ancestral homeland of the European Roma, in agreement with previous linguistic and anthropological studies.

Origins, admixture and founder lineages in European Roma

“…Ukrainian Romungro Roma were collected in three localities in the Zakarpattya region (Serednye, Antonivka, and Hudolovo) and Ukrainian hosts were sampled around Lviv. 31 Spanish Roma samples were collected in Barcelona 7 and Madrid, and they were Spanish speakers. The Spanish host population was obtained from the Spanish National DNA Bank.…”

“…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.…”

“…6 Despite these previous genetic studies, the Roma demographic history remains poorly understood. Y-chromosome and mtDNA lineages other than H and the M major haplogroups, respectively, have been attributed to genetic influences from populations along the proto-Roma migration way 7,21 without a more specific definition of their geographic origins. 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.…”