Hungarian mtDNA population databases from Budapest and the Baranya county Roma.

To facilitate forensic mtDNA testing in Hungary, we have generated control region databases for two Hungarian populations: 211 individuals were sampled from the urban Budapest population and 208 individuals were sampled from a Romani ("gypsy") population in Baranya county. Sequences were generated using a highly redundant approach to minimize potential database errors. The Budapest population had high sequence diversity with 180 lineages, 183 polymorphic positions, and a random match probability of 1%. In contrast, the Romani population exhibited low sequence diversity, with only 56 lineages, 109 segregating sites, and a random match probability of 8.8%. The mtDNA haplogroup compositions of the two populations were also distinct, with the large proportion of haplogroup M samples (35%) in the Roma the most obvious difference between the two populations. These factors highlight the importance of considering population structure when generating reference databases for forensic testing purposes. Comparisons between our Romani population sample and other published data indicate the need for heightened caution when sampling and using mtDNA databases of small endogamous populations. The Romani populations that we compared showed significant departures from genetic uniformity.