The Roma people, also known as gypsies, are currently the biggest and most widespread ethnic minority in the whole Europe, specially present in the central and south-eastern regions of the continent. Their linguistic, anthropological, cultural and genetic characteristics are evidences of their origin in the Indian subcontinent. However, due to the limited amount of data available and low resolution of the genetic studies that had been done until now, little was known about the genetic makeup of the first Roma populations and the genetic mixing that took place when they arrived in Europe.

Researchers at the Institute of Evolutionary Biology (IBE), a joint center of the University Pompeu Fabra and the Higher Council for Scientific Research (CSIC) , have now conducted a genetic analysis to determine the origin of the Roma. Through an exhaustive study of the genome regions that are uniparental (those that only come from the mother, as the mitochondrial genome, or only from the father, as the Y chromosome) has confirmed that the first Roma immigrated from North India. Furthermore, the have found that, probably, the Roma come from one small group of individuals who migrated at once, instead of several groups migrating successively from the same place, as it had been suggested.

This is the first time that a good representation of Roma in Europe is studied. In addition, volunteers have not been classified according to the European regions where they live, but researchers have taken into account the migrating clans that make up this population. Comparinguniparental genomes of  European Roma with those of non-Roma Europeans, scientists led by David Comas found that the presence of Roma genetic lineages  in non-Roma Europeans is small but not negligible, contradicting the hypothesis that the Roma have received only genetic influences Europe without providing them reciprocally.

However, one of the most interesting results is the discovery of some genetic lineages that are now only found in Roma but were originally from the non-Roma Europeans. The presence of these exclusive lineages in almost every gypsy groups is due to the "founder effect", which are the consequences of establishing a new population from a small number of individuals, and the existing inbreeding throughout time in this community.

"We have a lot of data about the cultural richness of the Roma, but we still have a lot to understand about their genetic diversity," says David Comas, head of the Human Genome Diversity of the IBE and professor of the Department of Experimental Sciences and Health (DCEXS) of the UPF. The Genographic Consortium, an international project that seeks to draw new knowledge about the migratory history of the human species and answer age-old questions surrounding the genetic diversity of humanity, also participated in the study, which is published in the September edition of the Journal of Human Genetics.

Reference article: Martínez-Cruz B, Mendizabal I, Harmant C, de Pablo R, Ioana M, Angelicheva D, Kouvatsi A, Makukh H, Netea MG, Pamjav H, Zalán A, Tournev I, Marushiakova E, Popov V, Bertranpetit J, Kalaydjieva L, Quintana-Murci L, and Comas D and the Genographic Consortium (2015). Origins, admixture and founder lineages in European Roma. European Journal of Human Genetics