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References OMIM Gene GeneReviews HGMD HGNC
last update : 22-10-2015
Symbol MDDS5
Location 8q22.3
Name mitochondrial DNA depletion syndrome, encephalomyopathic form
Other name(s)
  • Mitochondrial DNA depletion syndrome 8B (MNGIE type)
  • Mitochondrial DNA depletion syndrome 8A(encephalomyopathic type with renal tubulopathy)
  • Corresponding gene RRM2B
    Other symbol(s) MTDPS8A , MTDPS8B
    Main clinical features
  • severe mtDNA depletion syndrome with less than 1p100 mtDNA in skeletal muscle, with neonatal hypotonia, lactic acidosis, a proximal renal tubulopathy , neurologic deterioration and death in the first months of life
  • lipid myopathy with ragged red fibers, congenital deafness, generalized central hypomyelination, nephrocalcinosis, proximal tubulopathy and peripheral lactic acidemia
  • on brain MRI generalized mild hypomyelination
  • Genetic determination autosomal recessive
    Function/system disorder neurology
    Type disease
    Gene product
    Name cytosolic p-53-inducible ribonucleotide reductase small subunit (p53RB)
    Gene mutationChromosome rearrangementEffectComments
    various types     nonsense, missense and slice-site mutations and in-frame deletions