Correlation Between D4Z4 Repeats And Phenotype In Facioscapulohumeral Muscular Dystrophy

Objective :(1)To explore related factors of clinical severity in patients with facioscapulohumeral muscular dystrophy;(2)To explore the risk factors of pulmonary dysfunction occurrence inpatients with facioscapulohumeral muscular dystrophy.Design: we recruited 86 patients with facioscapulohumeral muscular dystrophy type 1,and written and informed consent was obtained from all participants. We recruited clinical data including age,sex,age at onset,family history,MMT,CSS,age-corrected CSS,D4Z4 repeats,Beevor sign,the ability of sit-up. When conducting an retrospective case-control study, we included patients with pulmonary function test and excluded patients with unqualified pulmonary function test and other pulmonary disease which may affect the effects.Results:(1) The age-corrected CSS in D4Z4 1-3 group was higher than that in D4Z4 4-10 group(p=0.005).(2) The age-corrected CSS in sporadic patients was higher than that in familial patients(p=0.009).(3) There was no difference between the age-corrected CSS in male group and that in female group(p=0.801).(4) The majority patients with pulmonary dysfunction were mild to moderate pulmonary dysfunction.(5) FVC predicted value,PEF predicted value and MVV predicted value between mild pulmonary dysfunction and moderate pulmonary dysfunction had significant difference(p value:0.000,0.014,0.001,respectively).(6)D4Z4 repeats had no significant difference between normal pulmonary function and pulmonary dysfunction. The ability of sit-up between normal pulmonary function and pulmonary dysfunction had significant difference(p=0.021).Conclusion:(1)D4Z4 repeats and family history may affect the severity of facioscapulohumeral muscular dystrophy. Sex may not affect the clinical severity of facioscapulohumeral muscular dystrophy.(2) D4Z4 repeats has no relationship with the occurrence of pulmonary dysfuncton in patients with facioscapulohumeral muscular dystrophy. The severity of motor damage cannot predict the occurrence of pulmonary dysfunction. However, the sit-up has correlation with the occurrence of pulmonary dysfuncton in patients with facioscapulohumeral muscular dystrophy. Moreover, it is necessary to supervise the pulmonary function in early-stage patients with facioscapulohumeral muscular dystrophy.