Abstract |
We report a new mutation, an A-->T transition at nt 3243 in the mitochondrial tRNA(leu)(UUR) gene, in a 9-year-old girl who presented with muscle weakness of 3 years duration complicated by rapidly progressive encephalopathy. In muscle, the activity of the mitochondrial respiratory chain complexes I, III, and IV was markedly reduced. The mutation, involving a highly conserved base pair in the dihydrouridine loop, was heteroplasmic in muscle (81.4%), skin (69.3%), and blood (13.8%) and was not present in blood of 50 healthy individuals. The mitochondrial 3243 base is a "hot spot" for mutations; an A-->G transition at this position is found in a high proportion in most MELAS patients. Since the A-->T transition creates a new recognition site for the restriction enzyme TspRI, both ApaI and TspRI should be used to exclude a mutation at nt 3243.
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Authors | A Shaag, A Saada, A Steinberg, P Navon, O N Elpeleg |
Journal | Biochemical and biophysical research communications
(Biochem Biophys Res Commun)
Vol. 233
Issue 3
Pg. 637-9
(Apr 28 1997)
ISSN: 0006-291X [Print] United States |
PMID | 9168904
(Publication Type: Case Reports, Comparative Study, Journal Article)
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Chemical References |
- DNA, Mitochondrial
- RNA, Transfer, Leu
- DNA Restriction Enzymes
- Deoxyribonucleases, Type II Site-Specific
- GGGCCC-specific type II deoxyribonucleases
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Topics |
- Base Sequence
- Child
- DNA Restriction Enzymes
- DNA, Mitochondrial
(genetics)
- Deoxyribonucleases, Type II Site-Specific
- Electron Transport
- Female
- Humans
- MELAS Syndrome
(diagnosis, genetics)
- Mitochondria, Muscle
(metabolism)
- Mitochondrial Encephalomyopathies
(diagnosis, genetics, metabolism)
- Point Mutation
- RNA, Transfer, Leu
(genetics)
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