A follow-up study in a Taiwanese family with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes syndrome.
OBJECTIVE
MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) syndrome is often associated with A3243G point mutation of mitochondrial DNA (mtDNA). We previously described a MELAS family characterized by harboring an additional approximately 260 bp tandem duplication in the D-loop and a novel C3093G point mutation in the 16S rRNA gene of mtDNA in the proband. We studied the clinical progression and fluctuation of mtDNA mutations in this Taiwanese MELAS family.


METHODS
We followed up the clinical course in all members of this family (1 proband, her mother and 3 sons) for 12 years. Mutations of mtDNA in serial muscle biopsies of the proband and blood samples and hair follicles taken at different time points from the members of this family were analyzed.


RESULTS
The proband developed repeated stroke-like episodes, chronic intestinal pseudo-obstruction, polyneuropathy, progressive renal failure and dilated cardiomyopathy with heart failure. During the follow-up period, the mother and one of the siblings of the proband developed stroke-like episodes at age 62 and 12, respectively. There was no significant difference in the proportions of mtDNA with A3243G mutation among five serial muscle biopsies of the proband. In one carrier (I-2), the proportion of A3243G mutated mtDNA in blood cells was slightly increased with disease progression.


CONCLUSIONS
This study underlines the importance of early detection of extraneuromuscular symptoms in the members of a family with MELAS syndrome by adequate follow-up. The age of onset of stroke-like episode in MELAS syndrome may be as late as 62 years. We suggest that the manifestations of MELAS syndrome in this family might be associated with the additional approximately 260 bp tandem duplication in the D-loop region and the coexistence of C3093G mutation in the 16S rRNA gene with the A3243G mutation of mtDNA.
Division of Neurology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
Jie-Yuan
JY
Li
Rong-Hong
RH
Hsieh
Nan-Jing
NJ
Peng
Ping-Hong
PH
Lai
Cheng-Feng
CF
Lee
Yuk-Keung
YK
Lo
Yau-Huei
YH
Wei
D000328:Adult; D002648:Child; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017241:MELAS Syndrome / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D013624:Taiwan
D004272:DNA, Mitochondrial