McArdle disease is caused by recessive mutations in PYGM gene. The condition is considered to cause a “pure” muscle phenotype with symptoms including exercise intolerance, inability to perform isometric activities, contracture, and acute rhabdomyolysis leading to acute renal failure. This is a retrospective observational study aiming to describe phenotypic and genotypic features of a large cohort of patients with McArdle disease between 2011 and 2019. Data relating to genotype and phenotype, including frequency of rhabdomyolysis, fixed muscle weakness, gout and comorbidities, inclusive of retinal disease (pattern retinal dystrophy) and thyroid disease, were collected. Data from 197 patients are presented. Seven previously unpublished PYGM mutations are described. Exercise intolerance (100%) and episodic rhabdomyolysis (75.6%) were the most common symptoms. Fixed muscle weakness was present in 82 (41.6%) subjects. Unexpectedly, ptosis was observed in 28 patients (14.2%). Hyperuricaemia was a common finding present in 88 subjects (44.7%), complicated by gout in 25% of cases. Thyroid dysfunction was described in 30 subjects (15.2%), and in 3 cases, papillary thyroid cancer was observed. Pattern retinal dystrophy was detected in 15 out of the 41 subjects that underwent an ophthalmic assessment (36.6%). In addition to fixed muscle weakness, ptosis was a relatively common finding. Surprisingly, dysfunction of thyroid and retinal abnormalities were relatively frequent comorbidities. Further studies are needed to better clarify this association, although our finding may have important implication for patient management.

中文翻译：

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197 名英国麦卡德尔病患者的表型和基因型：一项观察性单中心研究

麦卡德尔病是由PYGM基因的隐性突变引起的。该病症被认为会导致“纯”肌肉表型，其症状包括运动不耐受、无法进行等长运动、挛缩和导致急性肾功能衰竭的急性横纹肌溶解。这是一项回顾性观察研究，旨在描述 2011 年至 2019 年期间一大批麦卡德尔病患者的表型和基因型特征。与基因型和表型相关的数据，包括横纹肌溶解症的频率、固定性肌肉无力、痛风和合并症，包括视网膜收集疾病（型视网膜营养不良）和甲状腺疾病。提供了来自 197 名患者的数据。七个以前未发表的 PYGM描述了突变。运动不耐受 (100%) 和发作性横纹肌溶解症 (75.6%) 是最常见的症状。82 名 (41.6%) 受试者出现固定性肌肉无力。出乎意料的是，28 名患者 (14.2%) 出现上睑下垂。高尿酸血症是 88 名受试者 (44.7%) 的常见发现，25% 的病例并发痛风。30 名受试者 (15.2%) 出现甲状腺功能障碍，3 例出现甲状腺乳头状癌。在接受眼科评估的 41 名受试者中，有 15 名（36.6%）检测到模式性视网膜营养不良。除了固定的肌肉无力外，上睑下垂是一个相对常见的发现。令人惊讶的是，甲状腺功能障碍和视网膜异常是相对常见的合并症。需要进一步研究以更好地阐明这种关联，