Statistical analysis
Allele and genotype frequencies of each SNP were calculated by direct
counting. Genotype and allele frequencies between groups were compared
using the χ2 test and Fisher’s exact test when
appropriate. For allelic associations, p values with Yates correction
and odds ratio (OR) with 95% confidence intervals (CI) were calculated
using Statcalc program (Epiinfo version 6.0.4, CDC, Atlanta, GA).
Pair-wise LD (D’, r2) was estimated by use of
Haploview software version 4.2. For categorical data, chi-square tests
were performed, while the student’s t -test (or Mann Whitney U
test where appropriate) was performed to compare the continuous data.
Differences in mean with a p value <0.05 were deemed
significant. Standard errors of the means (and/or deviations) were also
calculated