Figure 1. Principal component map of mitochondrial DNA variation. The mitochondrial DNA data (with respect to the haplogroup frequencies in Table 2) of 16 reported regional Han populations were from references ([26,28] and references therein). The three Chaoshanese populations are marked by diamonds, whereas other Han Chinese populations are labeled by circles with city or province names above the circle. CS1M and CS1NC represent the Chaoshanese populations with (CS1M) and without (CS1NC) myopia in this study. CS2 indicates that the Chaoshanese mtDNA data were taken from a recent report [26]. This figure demonstrated that the Chaoshanese population in this study is identical to the Chaoshanese population previously reported but is different from other Chinese population based on mitochondrial DNA haplogroup analysis.