Men have a higher rate of completed suicide than women, which suggests that sex chromosome abnormalities may be related to the pathophysiology of suicide. Recent studies have found an aberrant loss of chromosome Y (LOY) in various diseases; however, no study has investigated whether there is an association between LOY and suicide. The purpose of this study was to determine whether LOY occurs in men who completed suicide. Our study consisted of 286 male Japanese subjects comprised of 140 suicide completers without severe physical illness (130 post-mortem samples of peripheral blood and 10 brains) and 146 age-matched control subjects (130 peripheral blood samples from healthy individuals and 16 post-mortem brains). LOY was measured as the chromosome Y/chromosome X ratio of the fluorescent signal of co-amplified short sequences from the Y-X homologous amelogenin genes (AMELY and AMELX). Regression analyses showed that LOY in the blood of suicide completers was significantly more frequent than that found in controls (odds ratio = 3.50, 95% confidence interval = 1.21–10.10), but not in the dorsolateral prefrontal cortex (DLPFC) region of brain. Normal age-dependent LOY in blood was found in healthy controls (r = -0.353, p < 0.001), which was not seen in suicide completers (r = -0.119, p = 0.177). DLPFC tissue had age-dependent LOY (B = -0.002, p = 0.015), which was independent of phenotype. To our knowledge, this is the first study demonstrating that LOY in blood is associated with suicide completion. In addition, our findings are the first to also indicate that age-dependent LOY may occur not only in blood, but also in specific brain regions.

男性完成自杀的比率高于女性，这表明性染色体异常可能与自杀的病理生理有关。最近的研究发现，在各种疾病中，Y染色体异常丢失。但是，没有研究调查LOY和自杀之间是否存在关联。这项研究的目的是确定LOY是否发生在自杀者中。我们的研究由286名日本男性受试者组成，包括140名没有严重身体疾病的自杀完成者（130名死者的外周血和10个大脑的尸检）和146名年龄匹配的对照受试者（130名健康人的外围血样和16个尸检）大脑）。AMELY和AMELX）。回归分析表明，自杀完成者血液中的LOY频率明显高于对照组（优势比= 3.50，95％置信区间= 1.21-10.10），但在大脑的背外侧前额叶皮层（DLPFC）区域则没有。在健康对照者中发现正常的年龄依赖性血液中LOY（r = -0.353，p <0.001），而在自杀完成者中则未见（r = -0.119，p = 0.177）。DLPFC组织具有年龄依赖性的LOY（B = -0.002，p = 0.015），与表型无关。据我们所知，这是第一项证明血液中LOY与自杀完成有关的研究。此外，我们的研究结果首次表明年龄相关的LOY不仅可能出现在血液中，而且可能出现在特定的大脑区域。