Home Page
References OMIM Gene GeneReviews HGMD HGNC
last update : 24-01-2014
Symbol MPEI1
Location 12q23.3
Name myopathy, with progressive exercice intolerance 1
Other name(s) myopathy with lactic acidosis, hereditary
Corresponding gene ISCU
Other symbol(s) HML
Main clinical features
  • lifelong exercise intolerance with symptoms of muscle fatigue, shortness of breath, and tachycardia with minor levels of physical exertion, associated with episodes of myoglobinuria
  • Genetic determination autosomal recessive
    Related entries including myopathy with deficiency of succinate dehydrogenase and aconitase
    Function/system disorder
    Type disease
  • associated with a decrease in the iron regulatory protein IRP1 and intracellular iron overload in skeletal muscle, consistent with a muscle-specific alteration of iron homeostasis
  • mutation observed in the patients results in aberrant splicing of the ISCU RNA, thereby resulting in a dysfunctional IscU protein with an incorrect C-terminal
  • intron mutation in the iron-sulfur cluster assembly gene ISCU, which leads to the activation of cryptic splice sites and the retention of part of intron 4, and PTBP1 was found to repress the defective splicing of ISCU, resulting in a drastic loss of mutant transcripts (PMID: 22125086))