The Comparative Study Of Clinical,Patho- Logical Features Between Patients Of DMRV With And Without GNE Gene Mutation

Objective:Distal myopathy with rimmed vacuoles (DMRV) is a syndrome presenting distal myopathy in clinic and rimmed vacuoles in pathology,originally described by Nonaka, characterized clinically by the preferential involvement of distal muscles of legs with sparing of quadriceps muscles in late teens or early adult hood, level of serum CK is normal or elevated slightly. Muscle biopsy is char-acterized by many rimmed vacuoles. Tubulofilamentous inclusions can be seen-in cytoplasm and nucleus.Hereditary inclusion body myopathy (HIBM), which was originally described as "rimmed vacuole myopathy" sparing the quadriceps, is very similar to DMRV both clinically and pathologically. Both diseases were shown to be associated with mutations in the gene encoding UDP-N-a-cetylgl-ucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) by Eisenberg and K-ayashima in 2001 and 2002.The DMRV/hIBM caused by mutations in GNE is renamed as GNE myopathy.We noticed that some patients diagnosised as DM-RV/hIBM clinically and pathologically had no mutations in GNE gene.There is no comparative study of clinical,pathological features between pa-t ients of DMRV with and without GNE gene mutations in China.Here we sum-marize 25 cases of DMRV and detect GNE gene to analyse and compare their clinical and pathological features.Material and methods:All cases are from the department of neurology of Qilu hospital,and diagn osised as DMRV clinically and pathologically.Muscular specimens are obtained by open operations with agreements of patients. The usual standard staining te chniques were performed on transverse (8μm) sections. DNA was extracted fro m WBC or muscle tissue of them and sequenced. All cases are divided into 2 groups according to sequencing results. Analysis and compare whether there w ere significant differences in clinical and pathological characteristics between 2 groups.Results:1. There are 13 cases have GNE gene mutations.Another 12 cases have no G NE gene mutations.2.10 famales have GNE mutations,while another 2 not. There are significant differences between the two groups.3. Age of onset of cases with GNE mutations was (22.8±3.3) (range 19-29 years). Age of onset of cases without GNE mutations was (28.8±12.6) ( range 5-46 years). The degree of dispersion is bigger in age of onset of ca ses without GNE mutations.4. Concentration of serum CK for cases with GNE mutations is (436.9±284. 1) (range normal-966U/L). Concentration of serum CK for cases without G NE mutations is (1072.3±1039.5) (ranges 62～3230U/L).5 cases without GNE mutations have higher CK level(>1000U/L).No case with GNE mutati ons has higher CK level(>1000U/L). There are significant differences betwe en the two groups.5.13 cases with GNE matations have involvement of gastrocnemius,while 7 c ases without GNE matations do. There are significant differences between t he two groups.6. No case with GNE matations presents formation of hypertrophy and split fi bers,while 6 cases without GNE matations do. There are significant differe nces between the two groups.7. Cases with GNE matations present more RVs.8. There is no significant difference in other clinical and pathological features between 2 groups.Conclusions:1. There are significant differences in gender composition, age of onset, seru m CK level, involvement of gastrocnemius muscle, number of RVs,formati on of hypertrophy and split fibers between 2 groups.2. There is no significant difference in other clinical and pathological features between 2 groups, suggesting that they might have unknown mutations,or had similar pathogenesis.