The distribution of mutations in hypervariable segment 1 (HVS1) of mitochondrial DNA (mtDNA) was analyzed for more than 37000 individuals from various regions of the world. The results were used to estimate the intensity of mutation processes and the features of the cold spot distribution in mtDNA. Analysis of the structural-functional organization and variation of HVS1 made it possible to associate a lower variation with functionally important HVS1 regions. The distribution of CAT cold spots in secondary DNA structures revealed a lack of correlation between the cold spot location and the structural type of the mtDNA region.