Premium
Myoclonus epilepsy and ragged‐red fibers: blood mitochondrial DNA heteroplasmy in affected and asymptomatic members of a family
Author(s) -
Piccolo G.,
Focher F.,
Verri A.,
Spadari S.,
Banfi P.,
Gerosa E.,
Mazzarello P.
Publication year - 1993
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.1993.tb05368.x
Subject(s) - heteroplasmy , mitochondrial dna , biology , asymptomatic , mutation , genetics , epilepsy , asymptomatic carrier , pathology , microbiology and biotechnology , medicine , gene , neuroscience
By a rapid PCR‐based method to assess the 8344 mtDNA mutation associated with MERRF disease, we have studied DNA from blood samples of 10 individuals belonging to a family spanning four generations in which one patient showed the complete MERRF phenotype, three other members were less severely affected, while the remaining were unaffected. The percentage of mutant mtDNA was quantified by laser‐densitometric scanning of the negative photographic sheets of the agarose gels. The results showed that the MERRF patient had 53% of mutated mtDNA while the two less affected patients had 62% and 14% of mutated mtDNA, respectively. However, a high percentage of mutated genomes (up to 64%) was also found in some unaffected relatives. These results show that although on one hand the mutation is probably the primary cause of the disease, on the other hand the relative amount of mutated mtDNA in blood samples is not indicative of its clinical expression.