Aim: To enhance our understanding of population history of Roma population and to assess their genetic risk for neurodegenerative and cardiovascular disorders. Methods: Allele frequencies of ApoE polymorphisms in 208 randomly selected Bayash Roma living in Croatia were investigated and compared with the data reported for 38 world populations. Results: Population analysis showed that ApoE polymorphism is characterized by a north-south gradient for E3 allele. The low frequency of E3 allele in Africa is the consequence of high frequencies of other alleles (E2, E4, and alleles that are not present outside Africa). A high level of polymorphy is also present in Bayash Roma where an « ; African pattern» ; of low frequencies of E3 (72.1%) and high frequency of both E2 (10.1%) and E4 (17.8%) allele is found what is unique finding among non-African populations. Namely, the frequency of allele E3 in non-African populations falls within range of 74%-90%, and among those characterized by lower frequencies of E3 allele, high frequency of only one of two risk alleles is present, either E4 (e.g. Finland) or E2 (e.g. Turkey or India). Conclusions: Since isolation of the population usually leads to monomorhy rather than to increased polymorphy, we take this « ; African pattern» ; of the Bayash Roma of Croatia as an unexpected finding that is most probably due to founder effect. However, high frequencies of E2 and E4, two alleles related to many health hazards, deserve attention since it implies that Bayash Roma carry increased genetic risk for neurodegenerative as well as cardiovascular disorders. |