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Background: Restriction fragment length polymorphisms (RFLPs) of the COL1A2 and CYP1A1 and short tandem repeats of HS1,2 Ig enhancer genes are proving to be useful markers for describing human populations and thus are of interest for anthropogenetic research. Moreover, they can provide useful information in identifying alleles and haplotypes associated with particular forms of common diseases or for pharmacogenomics studies., Aim: The objective of this study was to define the genetic structure of Libyan Tuaregs and to establish the degree of genetic homogeneity amongst the El Awaynat and Tahala groups., Subjects and Methods: Tuareg individuals from El Awaynat (n = 99) and Tahala (n = 18), in Libyan Sahara, were analysed for the RFLPs of COL1A2 and CYP1A1 and short tandem repeats of HS1,2 Ig enhancer genes. In order to provide a clearer picture of COL1A2, CYP1A1 and HS1,2 Ig enhancer allele and haplotype frequency distributions in various human groups distributed over a wide geographic area, comparisons with other African, European and Asian populations were carried out by analysis of molecular variance (AMOVA) and genetic distance analysis., Results: No significant level of differentiation was evident between the two Libyan Tuareg groups according to AMOVA. For the CYP1A1 gene, a possible new haplotype was observed, even though at a very low frequency. Linkage disequilibrium was assessed only for COL1A2, since CYP1A1 turned out to be poorly polymorphic for m2 and m3., Conclusions: Statistical analyses showed that Tuaregs from Libya are located in a intermediate position between south Saharan populations on one side and the Europeans and the Asians on the other.

Background: EcoRI, MspI and RsaI restriction fragment length polymorphisms (RFLPs) of the COL1A2 (type I collagen) gene are proving to be extremely informative markers for describing human populations; therefore they hold considerable potential for anthropogenetic research., Aim: The objective of this study was to characterize at the DNA level the Colorado Indians from Ecuador, for whom only blood group frequency information is available, and to investigate their relationships with the Cayapa-another Ecuadoran Native American group belonging to the same linguistic affiliation-and other world populations., Subjects and Methods: Colorado Indians (n = 80) were analysed for the three anthropologically informative RFLPs of the COL1A2 gene. To better define the genetic relationship between this group and other populations, principal component analysis (PCA) was performed and genetic distances were estimated. Population genetic structure was tested through analysis of molecular variance (AMOVA) by comparing haplotype frequencies., Results: COL1A2 allele and haplotype frequencies showed a certain degree of heterogeneity between the two Chibchan populations of Ecuador. The AMOVA test detected a significant level of differentiation (Fst = 0.034, p = 0.0049) between Colorado and Cayapa Indians. PC and genetic distance analyses showed a clear-cut separation between African and non-African populations; within the latter, the two Native American groups were differentiated from each other., Conclusions: The present findings suggest the presence of a low level of genetic relatedness between the Colorado and the Cayapa, despite their supposed common ethnogenesis. This confirms what has been inferred from other genetic data about the high degree of heterogeneity among Native Americans, even within the same linguistic branch, thus supporting the existence of genetic sub-structure within the central and southern American populations.