Chen Yinong, Zhang Shuai, Lu Xin, Xie Wanmu, Wang Chen, Zhai Zhenguo
Peking University China-Japan Friendship School of Clinical Medicine, Beijing, P.R. China.
National Center for Respiratory Medicine; State Key Laboratory of Respiratory Health and Multimorbidity; National Clinical Research Center for Respiratory Diseases; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences; Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, P.R. China.
BMC Pulm Med. 2024 Apr 22;24(1):194. doi: 10.1186/s12890-024-03016-7.
Patients with congenital myopathies may experience respiratory involvement, resulting in restrictive ventilatory dysfunction and respiratory failure. Pulmonary hypertension (PH) associated with this condition has never been reported in congenital ryanodine receptor type 1(RYR1)-related myopathy.
A 47-year-old woman was admitted with progressively exacerbated chest tightness and difficulty in neck flexion. She was born prematurely at week 28. Her bilateral lower extremities were edematous and muscle strength was grade IV. Arterial blood gas analysis revealed hypoventilation syndrome and type II respiratory failure, while lung function test showed restrictive ventilation dysfunction, which were both worse in the supine position. PH was confirmed by right heart catheterization (RHC), without evidence of left heart disease, congenital heart disease, or pulmonary artery obstruction. Polysomnography indicated nocturnal hypoventilation. The ultrasound revealed reduced mobility of bilateral diaphragm. The level of creatine kinase was mildly elevated. Magnetic resonance imaging showed myositis of bilateral thigh muscle. Muscle biopsy of the left biceps brachii suggested muscle malnutrition and congenital muscle disease. Gene testing revealed a missense mutation in the RYR1 gene (exon33 c.C4816T). Finally, she was diagnosed with RYR1-related myopathy and received long-term non-invasive ventilation (NIV) treatment. Her symptoms and cardiopulmonary function have been greatly improved after 10 months.
We report a case of RYR1-related myopathy exhibiting hypoventilation syndrome, type II respiratory failure and PH associated with restrictive ventilator dysfunction. Pulmonologists should keep congenital myopathies in mind in the differential diagnosis of type II respiratory failure, especially in patients with short stature and muscle weakness.
先天性肌病患者可能会出现呼吸受累，导致限制性通气功能障碍和呼吸衰竭。先天性1型兰尼碱受体（RYR1）相关肌病中从未报道过与此病症相关的肺动脉高压（PH）。
一名47岁女性因进行性加重的胸闷和颈部屈曲困难入院。她在孕28周时早产。其双下肢水肿，肌力为IV级。动脉血气分析显示通气不足综合征和II型呼吸衰竭，而肺功能测试显示限制性通气功能障碍，仰卧位时情况更糟。经右心导管检查（RHC）确诊为PH，无左心疾病、先天性心脏病或肺动脉阻塞的证据。多导睡眠监测表明夜间通气不足。超声显示双侧膈肌活动度降低。肌酸激酶水平轻度升高。磁共振成像显示双侧大腿肌肉炎症。左肱二头肌肌肉活检提示肌肉营养不良和先天性肌肉疾病。基因检测显示RYR1基因（外显子33 c.C4816T）存在错义突变。最后，她被诊断为RYR1相关肌病，并接受了长期无创通气（NIV）治疗。10个月后，她的症状和心肺功能有了很大改善。
我们报告了一例RYR1相关肌病病例，该病例表现为通气不足综合征、II型呼吸衰竭以及与限制性通气功能障碍相关的PH。在II型呼吸衰竭的鉴别诊断中，尤其是身材矮小和肌肉无力的患者，肺科医生应考虑到先天性肌病。
