目的探讨经基因及肌肉病理证实的4例线粒体脑肌病伴高乳酸血症和卒中样发作(mitochondrialencephalomyopathy with lactic acidosis and stroke—like episodes,MELAS)综合征患者的激素水平改变情况,并进行文献复习。方法 2009年10月～2011年12月北京天坛医院神经内科住院的4例MELAS综合征患者,4例患者均为男性,表现为卒中样发作、癫痫、身材矮小。1例患者存在第二性征发育迟滞,1例患者合并糖尿病。2例患者进行肌肉活检,4例患者进行线粒体基因检测和内分泌激素检查。结果 2例肌肉活检结果显示存在破碎红纤维,4例线粒体基因检测结果显示存在线粒体基因(A3243G)的突变。内分泌激素检查显示4例患者均存在内分泌异常,其中黄体生成素轻度降低1例,泌乳素增高2例,睾酮显著降低1例,甲状腺素轻度降低2例,胰岛素降低1例。结论 MELAS综合征惠者常合并内分泌异常,可存在多种内分泌激素水平的改变,包括性腺相关、甲状腺素、胰岛素等。应重视对MELAS综合征患者内分泌紊乱的诊断和治疗。 Objective To investigate the changes of hormone levels in 4 patients with mitochondrial encephalomyopathy and lactic acidosis and stroke-like episodes (MELAS) syndrome confirmed by gene and muscle pathology and to review the literature . Methods From October 2009 to December 2011, 4 patients with MELAS hospitalized in Department of Neurology, Beijing Tiantan Hospital were enrolled. All 4 patients were male, showing stroke-like seizures, epilepsy and short stature. One patient had secondary sexual development retardation and one patient had diabetes. Two patients underwent muscle biopsy and four patients underwent mitochondrial genetic testing and endocrine hormone tests. Results Two cases of muscle biopsy showed the presence of broken red fiber. The results of four mitochondrial genes showed that the mitochondrial gene (A3243G) was mutated. Endocrine examination revealed endocrine abnormalities in 4 patients, including 1 mild reduction of luteinizing hormone, 2 increased prolactin, 1 marked decrease of testosterone, 2 mild hypothyroidism and 1 insulin decrease. Conclusion MELAS syndrome often associated with endocrine abnormalities, there may be a variety of changes in endocrine hormones, including gonadal-related, thyroid hormone, insulin and so on. Should pay attention to the diagnosis and treatment of endocrine disorders in patients with MELAS syndrome.