ABSTRACT
A number of genes are considered to affect normal variation in human pigmentation. Recent studies have indicated that OCA2 is the crucial gene involved in the high variation of iris colour present among populations of European descent. In this study, eleven polymorphisms of the OCA2 gene were examined in search of their association with different pigment traits. The evolutionary tree scanning method indicated that the strongest phenotypic eye colour variation is associated with the branch defined by nonsynonymous change rs1800407, which refers to amino acid causing change Arg419Gln located in exon 13. Single SNP analysis indicated that allele 419Gln is associated with green/hazel iris colour (p < 0.001). According to tree scanning analysis, the proportion of eye colour variation explained by this nucleotide position is merely 4%. Thus, additional variation present in the OCA2 gene and perhaps some other pigment related genes must be taken into account in order to explain the high phenotypic variation in iris colour.
Subject(s)
Eye Color/genetics , Genetics, Population , Membrane Transport Proteins/genetics , Phylogeny , Polymorphism, Single Nucleotide/genetics , Bayes Theorem , DNA Primers/genetics , Genotype , Haplotypes/genetics , Humans , Models, Genetic , PolandABSTRACT
Frequency data of short tandem repeats (STR) loci included in the AmpF/STR Profiler Plus kit were collected from a sample of 253 random, unrelated individuals born in the south Poland region. All loci met Hardy-Weinberg expectation.
Subject(s)
Genetics, Population , Tandem Repeat Sequences/genetics , Alleles , Humans , Monte Carlo Method , PolandABSTRACT
The strength of any evidence can be assessed using a likelihood ratio (from Bayes' point of view). This is the ratio of the probabilities that the evidence would have been obtained given that the suspect is guilty and innocent, respectively. This, in turn, depends upon the probability that a match will be produced if the suspect is innocent. An essential population genetics parameter is the 'coancestry coefficient', or θ, or F(ST), which is the correlation between two genes sampled from distinct individuals within a subpopulation. In this paper, θ coefficients for the southern Polish population were calculated for three loci of forensic interest: TH01, TPOX and CSF1PO. Three small southern Polish subpopulations of different ethnic origin were analysed. The results suggest that values of θ appropriate to forensic applications are quite small in the southern Polish population (they vary in the range of 0.002 to 0.013), and the value of θ=0.03 suggested by the National Research Council is too conservative for the defendant.
