Mitochondrial recessive ataxic syndrome

from Wikipedia, the free encyclopedia
Classification according to ICD-10
G11.8 Other hereditary ataxias
ICD-10 online (WHO version 2019)

The mitochondrial recessive Fragile X syndrome ( MIRAS ), in the English literature as a syndrome of mitochondrial spinocerebellar ataxia and epilepsy (MSCAE) referred, is a very rare neurological disease. It can be assigned to the mitochondriopathies , the hereditary ataxias , the ataxia-neuropathy spectrum and the POLG-associated diseases . MIRAS is inherited in an autosomal recessive manner and is caused by mutations in the POLG gene. In Finland, MIRAS is the most common late-onset ataxia.

root cause

The disease is caused by mutations (homozygous or compound heterozygous) in the POLG gene (polymerase gamma). POLG codes for the DNA polymerase gamma and is located in humans on the long arm of chromosome 15 (15q24-q26). The polymerase gamma plays an important role in the replication of mitochondrial DNA . The mutations in the gene for the polymerase gamma lead to multiple deletions of mitochondrial DNA. The activity of the respiratory chain complexes I and IV is therefore restricted biochemically .

Clinical manifestations

MIRAS is characterized by an increasing gait disorder , speech disorder , weakened or abolished muscle reflexes on the legs, disturbed vibration sensation , nystagmus and other disorders of eye movements. In addition, epilepsy can occur and involuntary movements and cognitive impairment can occur.

further reading

  • M. Milone, R. Massie: Polymerase gamma 1 mutations: clinical correlations. In: The neurologist. Volume 16, Number 2, March 2010, pp. 84-91, ISSN  1074-7931 . doi : 10.1097 / NRL.0b013e3181c78a89 , PMID 20220442 .
  • BH Cohen, PF Chinnery et al .: POLG-Related Disorders . In: RA Pagon, TD Bird TD et al .: GeneReviews [Internet publication]. Seattle: University of Washington, 1993-16 March 2010. PMID 20301791 , full text freely available
  • J. Finsterer: Mitochondrial ataxias. In: The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques. Volume 36, Number 5, September 2009, pp. 543-553, ISSN  0317-1671 , PMID 19831121 , doi: 10.1017 / s0317167100008027 .
  • LA Bindoff, C. Tzoulis: Defining the Mitochondrial POLG-Related Spinocerebellar Ataxia and Epilepsy in Norway . In: Advances in clinical neuroscience and rehabilitation . Volume 11, Number 5, November / December 2011, full text freely accessible (PDF; 622 kB)
  • C. Tzoulis, LA Bindoff: The Syndrome of Mitochondrial Spinocerebellar Ataxia and Epilepsy caused by POLG mutations . Volume 9, Number 3, July / August 2009, full text freely accessible (PDF; 209 kB)

Individual evidence

  1. ↑ a b c Carmen Espinós, Vicente Felipo, Francesc Palau: Inherited neuromuscular diseases Springer-Verlag, 2009, ISBN 978-9048128129 , pp. 270-271
  2. ↑ a b J. Finsterer: Mitochondrial ataxias. In: The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques. Volume 36, number 5, September 2009, p. 549, ISSN  0317-1671 , PMID 19831121 , doi: 10.1017 / s0317167100008027 .
  3. ↑ POLG.  In: Online Mendelian Inheritance in Man . (English), last accessed on February 22, 2012