Clinical and genetic features in a MELAS child with a 3271T>C mutation.
A mitochondrial DNA 3271T>C point mutation was reported to be the second most common mutation (following the mutation 3243A>G) in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) in Japan. This mutation has rarely been reported in other countries. We present an 11-year-old Taiwanese girl with MELAS, who harbored the 3271T>C mutation and had manifested short stature, epilepsia partialis continua, and recurrent basal ganglia infarctions since age 6 years, and rapid intellectual regression, dysarthria, and unsteady gait since age 10 years. The proportion of 3271T>C mutant genomes in various tissues, including urinary sediments, hair follicles, blood leukocytes, and buccal mucosa cells from the patient and her mother, was analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis and quantitative real-time polymerase chain reaction. The proportion of mutant load in the patient's muscles was near 100%. Except for muscle, the highest mutation load was detected in urinary sediments of the patient by both methods. This is the first report involving mutant load analysis with quantitative real-time polymerase chain reaction in the 3271T>C mutation. The results suggest that urinary sediments may be an alternative tissue of choice which can be obtained noninvasively in the diagnosis of mitochondrial DNA 3271T>C mutations.
Chou
Hsiao-Feng
HF
Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Liang
Wen-Chen
WC
Zhang
Qing
Q
Goto
Yu-ichi
Y
Jong
Yuh-Jyh
YJ
D000483:Alleles; D002648:Child; D004272:DNA, Mitochondrial / Q000235:genetics; D004830:Epilepsy, Tonic-Clonic / Q000209:etiology; D005260:Female; D040741:Genetic Load; D006801:Humans; D017241:MELAS Syndrome / Q000150:complications / Q000235:genetics* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D018482:Muscle, Skeletal / Q000473:pathology; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction
D004272:DNA, Mitochondrial