J Genet Med.  1997 Sep;1(1):39-44.

Mutation Analyses in Korean patients with MELAS (Mitochondrial Encephalomyopathy, Lactic acidosis, and Stroke like episodes)

• Yoo HW
• Kim GH
• Ko TS

Abstract

The mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is inherited maternally, in which the MTTL1*MELAS 3243 mutation has been most commonly found as a heteropla smy of A to G point mutation in the tRNALeu(UUR) gene. The MTTL1*MELAS 3271 mutation is known to be the second common mutation, though clinical features of both mutations are not remarkably different. Recently, a variety of minor mutations have been reported in patients with MELAS. In this study, major efforts have been made to investigate the allele frequency of major three mutations including MTTL1*MELAS 3243, 3252, 3271 in 10 Korean families with MELAS probands. The PCR and subsequent direct sequencing of the PCR product in the regions spanning these three mutation sites were employed to identify the mutation in each proband. All family members have been screened for the presence of these three mutations by PCR-RFLP assay using Apa I, Acc I and Bfr I restriction enzymes. The MTTL1*MELAS 3243 mutation was most commonly found (7 out of 10 families tested) followed by the MTTL1*MELAS 3271 which was identified in 1 out of 10 families. In the remaining 2 families none of three mutations were found, indicating the presence of either nuclear mutation or yet unidentified mitochondrial DNA mutation in these families.

Keyword

MELAS; Mutation

MeSH Terms

Acidosis, Lactic*
DNA, Mitochondrial
Gene Frequency
Humans
MELAS Syndrome*
Point Mutation
Polymerase Chain Reaction
Stroke*
DNA, Mitochondrial