Mitochondrial polymorphisms were analyzed in PLINK for allelic association with 50,000 case-control permutations to obtain empirical p-values.

The number of individuals with mtDNA alleles shown in the far right columns is from the Ingman mt database (URL http://www.genpat.uu.se/mtDB/). A preliminary odds-ratio was calculated by comparing the affected allele frequency to the Ingman database [80]. All case-control differences were either in the control region, or a synonymous substitution in the third position in coding regions.