Ratia Nadja, Palu Edouard, Lantto Hanna, Ylikallio Emil, Luukkonen Ritva, Suomalainen Anu, Auranen Mari, Piirilä Päivi
Unit of Clinical Physiology, HUS Medical Diagnosis Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Unit of Neurophysiology, HUS Medical Diagnosis Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
Front Neurol. 2023 Nov 8;14:1277944. doi: 10.3389/fneur.2023.1277944. eCollection 2023.
Spinal muscular atrophy, Jokela type (SMAJ) is a rare autosomal dominantly hereditary form of spinal muscular atrophy caused by a point mutation c.197G>T in . is known to be involved in the regulation of mitochondrial function even though patients with SMAJ do not present with multiorgan symptoms of mitochondrial disease. We aimed to characterize the cardiopulmonary oxidative capacity of subjects with SMAJ compared to healthy controls and patients with mitochondrial myopathy.
Eleven patients with genetically verified SMAJ, 26 subjects with mitochondrial myopathy (MM), and 28 healthy volunteers underwent a cardiopulmonary exercise test with lactate and ammonia sampling. The effect of the diagnosis group on the test results was analysed using a linear model.
Adjusted for sex, age, and BMI, the SMAJ group had lower power output ( < 0.001), maximal oxygen consumption (VO max) ( < 0.001), and mechanical efficiency ( < 0.001) compared to the healthy controls but like that in MM. In the SMAJ group and healthy controls, plasma lactate was lower than in MM measured at rest, light exercise, and 30 min after exercise ( ≤ 0.001-0.030) and otherwise lactate in SMAJ was lower than controls and MM, in longitudinal analysis = 0.018. In MM, the ventilatory equivalent for oxygen was higher ( = 0.040), and the fraction of end-tidal CO lower in maximal exercise compared to healthy controls ( = 0.023) and subjects with SMAJ.
In cardiopulmonary exercise test, subjects with SMAJ showed a similar decrease in power output and oxidative capacity as subjects with mitochondrial myopathy but did not exhibit findings typical of mitochondrial disease.
约凯拉型脊髓性肌萎缩症（SMAJ）是一种罕见的常染色体显性遗传性脊髓性肌萎缩症，由 中的一个点突变c.197G>T引起。尽管SMAJ患者没有表现出线粒体疾病的多器官症状，但已知其参与线粒体功能的调节。我们旨在比较SMAJ患者与健康对照者及线粒体肌病患者的心肺氧化能力。
11例经基因验证的SMAJ患者、26例线粒体肌病（MM）患者和28名健康志愿者接受了心肺运动试验，并采集了乳酸和氨样本。使用线性模型分析诊断组对测试结果的影响。
在对性别、年龄和体重指数进行调整后，与健康对照者相比，SMAJ组的功率输出（<0.001）、最大耗氧量（VO₂max）（<0.001）和机械效率（<为0.001）较低，但与MM组相似。在SMAJ组和健康对照者中，静息、轻度运动和运动后30分钟时测得的血浆乳酸低于MM组（≤0.001 - 0.030），并且在纵向分析中，SMAJ组的乳酸水平低于对照组和MM组（=0.018）。在MM组中，与健康对照者（=0.040）和SMAJ患者相比，最大运动时的氧通气当量较高，而呼气末CO₂分数较低（=0.023）。
在心肺运动试验中，SMAJ患者的功率输出和氧化能力下降情况与线粒体肌病患者相似，但未表现出线粒体疾病的典型特征。
