ABSTRACT
Objective To report the spectrum of electron transfer flavoprotein dehydrogenase (ETFDH)gene mutations in 20 Chinese RR-LsM families.Methods Twenty-four RR-LSM patients in the First Hospital of Peking University from January 2003 to May 2010 were collected and the clinical characteristics were analyzed.These patients came from 20 families in North Mainland China.Sixteen families had 1 patient each.and the other 4 families had 2 patients.ETFDH gene analysis was performed in all patients,11 family members and 100 healthy controls.Results The mean onset age was(27.9±9.9)years.The main symptoms were limb weakness(21,87.5%),dysmasesia(15,62.5%),neck weakness (14,58.3%)and myalgia(14,58.3%).Eighteen patients had high level of acyleamitine.Fifteen of 17patients had glutaric aciduria.Seventeen ETFDH mutations,including 13 missense mutations,2 splice mutations,and 2 nonsense mutations,were identified in 19 families:c.998A>G,c.1450T>C,c.1703T>C,c.1717C>T,c.821G>A,c.643G>A,c.251C>T,c.1763A>T,c.IVS7+2T>C and c.IVS6+1G>A were Hovel mutations which were not found in 100 healthy controls.Nine families had the mutation of c.770A>G(P.Y257C)and 5 families had the mutation of c.1227A>C(P.L409F).Conclusions The numerous novel mutations in ETFDH gene indicate that Chinese RR-LSM might have special mutation pattern.c.770A>G(P.Y257C)and c.1227A>C(p.L409F)may be hot spot mutations in North Mainland China.
ABSTRACT
Objective To investigate the clinical features and electron transfer flavoprotein dehydrogenase (ETFDH) gene mutations in 35 Chinese patients with lipid storage myopathy. Methods The clinical data of 35 cases with lipid storage myopathy confirmed by muscle biopsy were collected. The sequences of all 13 exons of ETFDH were analyzed. Results All 35 patients showed proximal weakness. Ten of them demonstrated masseter weakness and 28 of them showed weakness in neck flexion. Twenty-nine of 32 patients who were followed up showed improvement after treatment with VitB2 and CoQ10. Mutations of ETFDH were found in 30 of 35 patients,which included 8 homozygosises,20 compound heterozygosises and 2 single heterozygosises. Fourteen novel mutations were found, including 9 missense mutations ( c. 3G > C, c. 152G>A, c. 191G > A, c.349G>C, c.433G>C, c. 949C > A, c. 1454C > G, c. 1744A >T and c. 1763A>G), 1 nonsense mutation(c. 172G>T), 2 deletions(c. 1282_1283del and 1773_1774del) and 2 splice mutations (c. 405 + 1G > T and c. 1691 -3C > G). Nine of them showed c. 250G > A mutation and 6 of them showed c. 770A > G mutation. Conclusions Lipid storage myopathy is presented as proximal weakness. Multiple acyl-CoA dehydrogenase deficiency caused by mutations of ETFDH is the major cause of lipid storage disease in this group. ETFDH c. 250G > A and c. 770A > G mutations show a high frequency.