摘要本文报道1例新生儿期起病以呼吸困难和低氧血症为早期表现，经基因检测确诊为多发性线粒体功能障碍综合征3型的患儿。患儿生后出现呼吸困难，表现为鼻翼扇动，三凹征阳性，低氧血症。鼻导管吸氧治疗可改善以上表现，但有持续低流量氧需求；胸部X射线检查提示“钟”形胸廓，肺动脉高压。全外显子组测序结果示，患儿 IBA57基因c.341+1G>A、c.785G>A（p.G262D）复合杂合致病变异，分别来自母亲和父亲。患儿3月龄开始出现症状性癫痫、眼球震颤、中枢性呼吸衰竭。头颅MRI符合线粒体白质脑病表现。左卡尼汀、维生素B 2、维生素B 1、维生素E、辅酶Q10、左乙拉西坦及气管插管呼吸机辅助呼吸治疗，仍有反复抽搐发作，治疗效果欠佳，放弃治疗后死亡。

abstractsThis article reported a case of multiple mitochondrial dysfunction syndrome type 3 with the early manifestation of dyspnea and hypoxemia. The patient was a male newborn who had dyspnea, which was manifested as nasal flaring, three concave sign, and hypoxemia after birth. These manifestations were improved after oxygen support through nasal cannula, but continuous low-flow oxygen therapy was needed. Chest X-ray indicated a bell-shaped thorax with pulmonary hypertension. Whole-exome sequencing identified compound heterozygous variants of c.341+1G>A and c.785G>A (p.G262D) in IBA57 gene of the patient, which were pathogenic and inherited from his mother and father, respectively. Symptomatic epilepsy, nystagmus, and central respiratory failure appeared at the age of 3 months. Cranial magnetic resonance image findings were consistent with the signs of mitochondrial leukoencephalopathy. The patient still had recurrent convulsions despite the treatment with levocarnitine, vitamin B 2, vitamin B 1, vitamin E, coenzyme Q10, levetiracetam, and mechanical ventilation through a tracheal tube. The patient showed a poor response to the treatment and died after withdrawing from treatment.