Background Short-chain enoyl-CoA hydratase (ECHS1) deficiency is a rare metabolic disorder. Concerned patients present with Leigh syndrome symptoms or a Leigh-like syndrome. Only 58 patients are known worldwide. The ECHS1 is a key component in β-oxidation and valine catabolic pathways.

Case Here we report a 6-month-old Lebanese boy born to consanguineous parents. He presented an increased muscle tone, hyperexcitability, feeding problems, horizontal nystagmus, and developmental delay. Magnetic resonance imaging of the brain revealed frontal brain atrophy, corpus callosum atrophy, and T2 hyperintensity in pallidum, internal capsule, pons, and thalamus. In the postsedation phase, the patient displayed a sudden generalized seizure with transition to status epilepticus. Therefore, we conducted metabolic examinations, which showed elevated levels of 2-methyl-2,3-DiOH-butyrate and 3-methylglutaconate in urine. Single exome sequencing revealed the homozygous mutation c.476A > G in the ECHS1 gene.

Conclusion This case report describes the clinical symptoms and the diagnostics of ECHS1 deficiency. It shows the importance of further metabolic and genetic testing of patients with motoric conspicuities and developmental delay. It is important to be cautious with propofol sedation of patients who present an unknown neurological disorder, when metabolic disturbance or especially mitochondriopathy is suspected.

背景 短链烯酰辅酶A水合酶（ECHS1）缺乏症是一种罕见的代谢紊乱。相关患者出现 Leigh 综合征症状或 Leigh 样综合征。全世界仅已知 58 名患者。ECHS1 是 β 氧化和缬氨酸分解代谢途径中的关键成分。

案例 在这里，我们报告一个 6 个月大的黎巴嫩男孩，其父母是近亲。他表现出肌肉张力增加、过度兴奋、喂养问题、水平眼球震颤和发育迟缓。脑部磁共振成像显示额叶脑萎缩，胼胝体萎缩，苍白球、内囊、脑桥和丘脑 T2 高信号。在镇静后阶段，患者表现出突然的全身性癫痫发作并过渡到癫痫持续状态。因此，我们进行了代谢检查，结果显示尿液中 2-methyl-2,3-DiOH-butyrate 和 3-methylglutaconate 水平升高。单外显子组测序揭示了ECHS1基因中的纯合突变 c.476A > G。

结论 本病例报告描述了 ECHS1 缺乏症的临床症状和诊断方法。它显示了对患有运动显着和发育迟缓的患者进行进一步代谢和基因检测的重要性。当怀疑有代谢紊乱或特别是线粒体病时，对表现出未知神经系统疾病的患者进行丙泊酚镇静时要谨慎，这一点很重要。