Child Neurology and Psychiatry Unit, Department of Clinical and Experimental Medicine, University of Catania - Policlinico, Via Santa Sofia, 78, 95123, Catania, Italy.
Laboratory of Neuro-Biomechanics, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.
Orphanet J Rare Dis. 2024 Feb 2;19(1):39. doi: 10.1186/s13023-024-03027-x.
Congenital disorders of glycosylation (CDG) are genetic diseases caused by impaired synthesis of glycan moieties linked to glycoconjugates. Phosphomannomutase 2 deficiency (PMM2-CDG), the most frequent CDG, is characterized by prominent neurological involvement. Gait disturbance is a major cause of functional disability in patients with PMM2-CDG. However, no specific gait assessment for PMM2-CDG is available. This study analyses gait-related parameters in PMM2-CDG patients using a standardized clinical assessment and instrumented gait analysis (IGA).
Seven adult patients with a molecular diagnosis of PMM2-CDG were followed-up from February 2021 to December 2022 and compared to a group of healthy control (HC) subjects, matched for age and sex. Standardized assessment of disease severity including ataxia and peripheral neuropathy along with isometric muscle strength and echo-biometry measurements at lower limbs were performed. IGA spatiotemporal parameters were obtained by means of a wearable sensor in basal conditions. PMM2-CDG patients displayed lower gait speed, stride length, cadence and symmetry index, compared to HC. Significant correlations were found among the used clinical scales and between disease severity (NCRS) scores and the gait speed measured by IGA. Variable reduction of knee extension strength and a significant decrease of lower limb muscle thickness with conserved echo intensity were found in PMM2-CDG compared to HC.
The study elucidates different components of gait disturbance in PMM2-CDG patients and shows advantages of using wearable sensor-based IGA in this frame. IGA parameters may potentially serve as quantitative measures for follow-up or outcome quantification in PMM2-CDG.
先天性糖基化障碍（CDG）是一种由于糖缀合物上聚糖部分合成受损而导致的遗传疾病。磷酸甘露糖变位酶 2 缺乏症（PMM2-CDG）是最常见的 CDG，其特征是明显的神经受累。步态障碍是 PMM2-CDG 患者功能障碍的主要原因。然而，目前尚无针对 PMM2-CDG 的特定步态评估方法。本研究使用标准化临床评估和仪器化步态分析（IGA）分析 PMM2-CDG 患者的步态相关参数。
2021 年 2 月至 2022 年 12 月，7 名成年 PMM2-CDG 患者接受了随访，并与年龄和性别匹配的健康对照组（HC）进行了比较。对疾病严重程度（包括共济失调和周围神经病）进行了标准化评估，同时还进行了下肢等长肌肉力量和超声生物测量测量。通过可穿戴传感器在基础条件下获得 IGA 时空参数。与 HC 相比，PMM2-CDG 患者的步速、步长、步频和对称指数较低。在使用的临床量表之间以及疾病严重程度（NCRS）评分和 IGA 测量的步速之间发现了显著的相关性。与 HC 相比，PMM2-CDG 患者的膝关节伸展力量降低，下肢肌肉厚度明显减少，而回声强度保持不变。
本研究阐明了 PMM2-CDG 患者步态障碍的不同成分，并表明在这种情况下使用基于可穿戴传感器的 IGA 的优势。IGA 参数可能作为 PMM2-CDG 随访或结果量化的定量测量。
