Complex II deficiencyA case report and review of the literature
Complex II deficiencyA case report and review of the literature
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DOI：
10.1002/ajmg.a.35714
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发表时间：
2013-02-01
影响因子：
2
通讯作者：
Raiman, Julian
中科院分区：
文献类型：
--
作者：
Jain-Ghai, Shailly;Cameron, Jessie M.;Raiman, Julian
复合物II缺乏是线粒体呼吸链缺陷的罕见原因，患病率为223%。它仅由细胞核编码，在柠檬酸循环中通过将琥珀酸氧化为富马酸而发挥作用，在线粒体电子传递链（ETC）中通过将电子转移至泛醌而发挥作用。在四个亚基中，SDHA和SDHB是催化亚基，SDHC和SDHD是锚定亚基。SDHA和SDHAF 1（组装因子）突变已在CII缺陷和线粒体表型患者中发现。我们报告一位CII缺乏症的病人，有先前未描述的扩张型心肌病、左心室致密化不全、发育迟缓、张力减退。此外，对文献中发表的36例病例进行了全面审查。结果表明，CII缺乏症具有可变的表型，与肌肉中的残留复合物活性无关，尽管在一个家族内表型和酶活性是可比的。对于一些人来说，这种情况在婴儿期是致命的，其他人有多系统受累，有些人在成年期发病，症状轻微，认知正常。最常见的是神经系统受累，脑成像通常显示白质脑病、Leigh综合征或小脑萎缩。SDHAF1突变与白质脑病相关。其他器官系统如心脏、肌肉和眼睛仅涉及约50%的病例，但心肌病与高死亡率和发病率相关。在一些患者中，核黄素提供了临床改善。(c)2013 Wiley Periodicals，Inc.
Complex II deficiency is a rare cause of mitochondrial respiratory chain defects with a prevalence of 223%. It is exclusively nuclear encoded and functions in the citric acid cycle by oxidizing succinate to fumarate and in the mitochondrial electron transport chain (ETC) by transferring electrons to ubiquinone. Of the four subunits, SDHA and SDHB are catalytic and SDHC and SDHD are anchoring. Mutations in SDHA and SDHAF1 (assembly factor) have been found in patients with CII deficiency and a mitochondrial phenotype. We present a patient with CII deficiency with a previously undescribed phenotype of dilated cardiomyopathy, left ventricular noncompaction, failure to thrive, hypotonia, and developmental delay. Also, a comprehensive review of 36 cases published in the literature was undertaken. The results show that CII deficiency has a variable phenotype with no correlation with residual complex activity in muscle although the phenotype and enzyme activities are comparable within a family. For some, the condition was fatal in infancy, others had multisystem involvement and some had onset in adulthood with mild symptoms and normal cognition. Neurological involvement is most commonly observed and brain imaging commonly shows leukoencephalopathy, Leigh syndrome, or cerebellar atrophy. Mutations in SDHAF1 are associated with leukoencephalopathy. Other organ systems like heart, muscle, and eyes are only involved in about 50% of the cases but cardiomyopathy is associated with high mortality and morbidity. In some patients, riboflavin has provided clinical improvement. (c) 2013 Wiley Periodicals, Inc.