1.Clinical and genetic characteristics of late-onset facioscapulohumeral muscular dystrophy type 1
Fuze ZHENG ; Xinyue CHEN ; Meng YU ; Liangliang QIU ; Minghui ZENG ; Yuhua LIN ; Feng LIN ; Wei ZHANG ; Minting LIN ; Ning WANG ; Yun YUAN ; Zhiqiang WANG ; Zhaoxia WANG
Chinese Journal of Neurology 2025;58(10):1040-1047
Objective:To summarize the clinical and genetic characteristics of late-onset facioscapulohumeral muscular dystrophy type 1 (FSHD1) patients, and to compare the differences between late-onset and classic-onset FSHD1 patients.Methods:A retrospective analysis was conducted on the clinical and genetic data of genetically confirmed late-onset FSHD1 patients (age at onset30 years) between January 2007 and June 2024 from the Department of Neurology of Peking University First Hospital and the First Affiliated Hospital of Fujian Medical University. Classic-onset FSHD1 patients (10 yearsage at onset≤30 years) were matched 1∶1 according to sex and disease duration for comparison. The demographic information, the number of D4Z4 repeat units, the distal D4Z4 methylation levels, FSHD Clinical Score (CS), Clinical Severity Score (CSS), and Age-Corrected Clinical Severity Score (ACSS) of these patients were collected. Survival analysis was performed to compare the outcome of lower extremity involvement between late-onset and classic-onset FSHD1 patients. The correlation of the number of D4Z4 repeat units and D4Z4 methylation level with CS and ACSS was analyzed in late-onset FSHD1 patients.Results:A total of 61 patients with late-onset FSHD1 were enrolled, 33 (54.1%) of whom are female, with an age of 54.0 (46.0, 62.0) years and a disease duration of 14.0 (5.5, 22.5) years. Compared to classic-onset FSHD1 patients, late-onset patients exhibited significantly lower CS [7.0 (5.6, 8.4) vs 6.0 (4.4, 7.7), U=1 416.000, P=0.013], CSS [3.0 (2.8, 3.3) vs 3.0 (2.0, 4.0), U=2 352.000, P=0.010], and ACSS [189.2 (137.1, 241.3) vs 96.8 (61.3, 132.2), U=3 225.500, P0.001], and higher proportion of patients with limb girdle involvement but no facial muscle involvement [18.0% (11/61) vs 6.6% (4/61), χ2=3.725, P=0.054]. Kaplan-Meier survival analysis showed that the onset age of lower extremity involvement in late-onset patients (45 years, 95% CI 42-48 years) was significantly higher than that in classic-onset patients (24 years, 95% CI 21-27 years, χ2=61.012, P0.001). The duration from symptom onset to lower extremity involvement in late-onset patients (15 years, 95% CI 10-20 years) was significantly longer than that in classic-onset patients (8 years, 95% CI 3-13 years, χ2=9.105, P=0.003). Late-onset FSHD1 patients carried higher average distal D4Z4 methylation levels compared to those with classic-onset FSHD1 [46.68% (40.79%,52.57%) vs 41.02% (34.03%,48.00%), U=1 378.500, P=0.014]. Among late-onset FSHD1 patients, cytosine-phosphate-guanine 6 (CpG6) methylation levels were significantly negatively correlated with ACSS ( r=-0.278, P=0.025); the number of D4Z4 repeat units were significantly negatively correlated with ACSS ( r=-0.272, P=0.034);CpG6 methylation levels were significantly negatively correlated with CS ( r=-0.441, P=0.003), while no correlation was found between number of D4Z4 repeat units and CS ( r=-0.161, P=0.310). Conclusions:Compared with classic-onset FSHD1 patients, late-onset FSHD1 patients are associated with a higher degree of distal D4Z4 methylation, along with a milder muscle weakness phenotype, slower disease progression and a higher proportion of cases without facial muscle involvement. The age at onset can be used as a marker of the severity and prognosis in FSHD1.
2.Clinical and genetic characteristics of late-onset facioscapulohumeral muscular dystrophy type 1
Fuze ZHENG ; Xinyue CHEN ; Meng YU ; Liangliang QIU ; Minghui ZENG ; Yuhua LIN ; Feng LIN ; Wei ZHANG ; Minting LIN ; Ning WANG ; Yun YUAN ; Zhiqiang WANG ; Zhaoxia WANG
Chinese Journal of Neurology 2025;58(10):1040-1047
Objective:To summarize the clinical and genetic characteristics of late-onset facioscapulohumeral muscular dystrophy type 1 (FSHD1) patients, and to compare the differences between late-onset and classic-onset FSHD1 patients.Methods:A retrospective analysis was conducted on the clinical and genetic data of genetically confirmed late-onset FSHD1 patients (age at onset30 years) between January 2007 and June 2024 from the Department of Neurology of Peking University First Hospital and the First Affiliated Hospital of Fujian Medical University. Classic-onset FSHD1 patients (10 yearsage at onset≤30 years) were matched 1∶1 according to sex and disease duration for comparison. The demographic information, the number of D4Z4 repeat units, the distal D4Z4 methylation levels, FSHD Clinical Score (CS), Clinical Severity Score (CSS), and Age-Corrected Clinical Severity Score (ACSS) of these patients were collected. Survival analysis was performed to compare the outcome of lower extremity involvement between late-onset and classic-onset FSHD1 patients. The correlation of the number of D4Z4 repeat units and D4Z4 methylation level with CS and ACSS was analyzed in late-onset FSHD1 patients.Results:A total of 61 patients with late-onset FSHD1 were enrolled, 33 (54.1%) of whom are female, with an age of 54.0 (46.0, 62.0) years and a disease duration of 14.0 (5.5, 22.5) years. Compared to classic-onset FSHD1 patients, late-onset patients exhibited significantly lower CS [7.0 (5.6, 8.4) vs 6.0 (4.4, 7.7), U=1 416.000, P=0.013], CSS [3.0 (2.8, 3.3) vs 3.0 (2.0, 4.0), U=2 352.000, P=0.010], and ACSS [189.2 (137.1, 241.3) vs 96.8 (61.3, 132.2), U=3 225.500, P0.001], and higher proportion of patients with limb girdle involvement but no facial muscle involvement [18.0% (11/61) vs 6.6% (4/61), χ2=3.725, P=0.054]. Kaplan-Meier survival analysis showed that the onset age of lower extremity involvement in late-onset patients (45 years, 95% CI 42-48 years) was significantly higher than that in classic-onset patients (24 years, 95% CI 21-27 years, χ2=61.012, P0.001). The duration from symptom onset to lower extremity involvement in late-onset patients (15 years, 95% CI 10-20 years) was significantly longer than that in classic-onset patients (8 years, 95% CI 3-13 years, χ2=9.105, P=0.003). Late-onset FSHD1 patients carried higher average distal D4Z4 methylation levels compared to those with classic-onset FSHD1 [46.68% (40.79%,52.57%) vs 41.02% (34.03%,48.00%), U=1 378.500, P=0.014]. Among late-onset FSHD1 patients, cytosine-phosphate-guanine 6 (CpG6) methylation levels were significantly negatively correlated with ACSS ( r=-0.278, P=0.025); the number of D4Z4 repeat units were significantly negatively correlated with ACSS ( r=-0.272, P=0.034);CpG6 methylation levels were significantly negatively correlated with CS ( r=-0.441, P=0.003), while no correlation was found between number of D4Z4 repeat units and CS ( r=-0.161, P=0.310). Conclusions:Compared with classic-onset FSHD1 patients, late-onset FSHD1 patients are associated with a higher degree of distal D4Z4 methylation, along with a milder muscle weakness phenotype, slower disease progression and a higher proportion of cases without facial muscle involvement. The age at onset can be used as a marker of the severity and prognosis in FSHD1.

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