Mitochondrial DNA (mtDNA) haplogroup (hg) H has been reported as a susceptibility factor for hypertrophic cardiomyopathy (HCM). This was established in genetic association studies, however, the SNP or SNP’s that are associated with the increased risk have not been identified. Hg H is the most frequent European mtDNA hg with greater than 80 subhaplogroups (subhgs) each defined by specific SNPs. We tested the hypothesis that the distribution of H subhgs might differ between HCM patients and controls. The subhg H distribution in 55 HCM index cases was compared to that of two Danish mtDNA hg H control groups (n = 170 and n = 908, respectively). In the HCM group, H and 12 different H subhgs were found. All these, except subhgs H73, were also found in both control groups. The HCM group was also characterized by a higher proportion of H3 compared to H2. In the HCM group the H3/H2 proportion was 1.7, whereas it was 0.45 and 0.54 in the control groups. This tendency was replicated in an independent group of Hg H HCM index cases (n = 39) from Queensland, Australia, where the H3/H2 ratio was 1.5. In conclusion, the H subhgs distribution differs between HCM cases and controls, but the difference is subtle, and the understanding of the pathogenic significance is hampered by the lack of functional studies on the subhgs of H.

线粒体DNA（mtDNA）单倍群（hg）H已被报道为肥厚型心肌病（HCM）的易感因素。这是在遗传关联研究中确定的，但是，尚未确定与增加的风险相关的SNP或SNP。Hg H是欧洲最常见的mtDNA hg，具有超过80个亚单体组（subhggroup），每个亚单体组均由特定的SNP定义。我们检验了HCM患者和对照组之间H亚型的分布可能不同的假设。将55个HCM指数病例中的subhg H分布与两个丹麦mtDNA hg H对照组（n = 170和n分别为908）。在HCM组中，发现了H和12个不同的H亚型。在两个对照组中都发现了除H73亚型以外的所有这些。HCM组的特征还在于，与H2相比，H3的比例更高。在HCM组中，H3 / H2比例为1.7，而在对照组中分别为0.45和0.54。这种趋势在澳大利亚昆士兰州的Hg H HCM指数独立病例组（n = 39）中得到了重复，其中H3 / H2比为1.5。总之，HCM病例和对照组之间的H亚型分布不同，但是差异很小，并且由于缺乏对H亚型的功能研究而妨碍了对致病意义的理解。