Population variation of human mitochondrial DNA (HV1 and HV2) in Spanish unrelated individuals (Northeast Spain)

Abstract A population database from 200 unrelated Caucasian individuals living in Spain was generated. Sequence polymorphisms of the mitochondrial DNA (mtDNA) control region, hypervariable regions I and II (HVRI and HVRII) were determined by polymerase chain reaction (PCR) and direct sequencing. A total of 175 different sequences were found as defined by 154 variable positions. The most common sequence occurred 10 times, this sequence is also the most frequent in other European populations such as Austrian, German and British. The mean pairwise difference for the two regions taken together was 8.25. The study revealed that transitions made up the majority of the deviations (88%), whereas we observed a significantly lower frequency of transversions (8%). A statistical estimate of the results for this Caucasian population showed a genetic diversity of 0.9965. The probability of two random individuals showing identical mtDNA haplotypes is 0.84%. In order to use the mtDNA analysis in forensic casework, we consider that it is of crucial importance to know the frequency of the different sequences of mtDNA, and this database study could be a useful tool to evaluate statistically the results.