Background: It is well-documented that though living in the same geographical area, European Roma
and their host populations have distinct genetic ancestries. Nevertheless, there are very few studies addressing
diversity of pharmacogenetic significance in Roma groups. The main goal of the present
study was to characterise the Portuguese Gypsies for a selected battery of SNPs located in genes
known to influence the response to drugs (TPMT, CYP2C9, CYP2C19, NAT2, and VKORC1) in comparison
to their host population.
Methods: The DNA of 116 Portuguese Gypsies and 70 Portuguese non-Gypsies individuals was genotyped using a multiplex
PCR-minisequencing assay for the following SNPs: TPMT*2, TPMT*3B, TPMT*3C, TPMT*8, CYP2C9*2,
CYP2C9*3, CYP2C19*2, NAT2*5, NAT2*13, and VKORC1 c.-1639G>A. Comparative analyses were performed and extended
to other populations for which allelic frequencies were available from the literature.
Results: Comparisons between Portuguese Gypsies and non-Gypsies only revealed significant differences for CYP2C9*2.
In the worldwide geographical context, both samples fitted well the pattern of pharmacogenetic diversity found in Europe.
However, in the Euro-Indian framework, Gypsies revealed to be closer to Indian populations, especially from North India,
than did the Portuguese non-Gypsies.
Conclusion: From the pharmacogenetic point of view, the Gypsies from Portugal do not seem to raise additional public
health concerns comparatively to other Portuguese. This study illustrates how important signs of the demographic past of
a population can be captured by the fraction of pharmacogenetically relevant genetic diversity.