Mutation History of the Roma/Gypsies

Abstract

The 8-10 million European Roma/Gypsies are a founder population of common origins that has subsequently split into multiple socially divergent and geographically dispersed Gypsy groups. Unlike other founder populations, whose genealogy has been extensively documented, the demographic history of the Gypsies is not fully understood and, given the lack of written records, has to be inferred from current genetic data. In this study, we have used five disease loci harboring private Gypsy mutations to examine some missing historical parameters and current structure. We analyzed the frequency distribution of the five mutations in 832-1,363 unrelated controls, representing 14 Gypsy populations, and the diversification of chromosomal haplotypes in 501 members of affected families. Sharing of mutations and high carrier rates supported a strong founder effect, and the identity of the congenital myasthenia 1267delG mutation in Gypsy and Indian/Pakistani chromosomes provided the best evidence yet of the Indian origins of the Gypsies. However, dramatic differences in mutation frequencies and haplotype divergence and very limited haplotype sharing pointed to strong internal differentiation and characterized the Gypsies as a founder population comprising multiple subisolates. Using disease haplotype coalescence times at the different loci, we estimated that the entire Gypsy population was founded approximately 32-40 generations ago, with secondary and tertiary founder events occurring approximately 16-25 generations ago. The existence of multiple subisolates, with endogamy maintained to the present day, suggests a general approach to complex disorders in which initial gene mapping could be performed in large families from a single Gypsy group, whereas fine mapping would rely on the informed sampling of the divergent subisolates and searching for the shared genomic region that displays the strongest linkage disequilibrium with the disease.

Origins, admixture and founder lineages in European Roma

“…We searched for matches of M-haplotypes present in European Roma within India, under the assumption that all the European Roma originated from the same region. The highest probability for the mtDNA in Roma populations was found in NW India (P = 0.713; Table 2), in agreement with previous studies, 6,7,9 linguistic, anthropological, and historical evidences. 1 The evolution of the population size through time was modeled for the M-lineages in a BSP (Supplementary Figure S4), assuming that these lineages will reveal the demographic history of the proto-Roma population before its arrival into Europe.…”

“…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.…”

“…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.…”

LTBP2 and CYP1B1 mutations and associated ocular phenotypes in the Roma/Gypsy founder population

“…The population genetics of PCG is peculiar and different from other Mendelian disorders in the Gypsies. Although four of the currently known mutations seem to have been 'taken out' of the Indian subcontinent, supporting our previous genetic data on the origin of the Gypsies, 31,36,37 the allelic diversity in PCG contradicts our previous data suggesting a small number of related founders. 31 The existing information does not allow conclusions on the parental population(s) in India/Pakistan and time of separation.…”

Founder effect and estimation of the age of the French Gypsy mutation associated with Glanzmann thrombasthenia in Manouche families

“…Records on linguistics, cultural anthropology and demography Dating French Gypsy mutation in thrombasthenia M Fiore et al describe the Gypsies as a population with Indian origins, with an initial exodus into Byzantium Empire dated approximately to the eleventh century, and a subsequent dispersal throughout Europe by the fifteenth century (Figure 3). [25][26][27][28][29] The migration of Gypsies in France took two routes: the first, through the North of Europe, and the second from Persia through North-Africa. Gypsies recognize 10,11,15 On the basis of our results, it is possible to infer the migration history of these Manouche families in France (Figure 3).…”