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Generation of Genomic Deletions in Mammalian Cell Lines via CRISPR/Cas9
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Risk of developing a mitochondrial DNA deletion disorder

Patrick F Chinnery1, Salvatore DiMauro, Sara Shanske

  • 1Neurology, University of Newcastle upon Tyne, Newcastle upon Tyne, UK. P.F.Chinnery@ncl.ac.uk

Lancet (London, England)
|August 18, 2004
PubMed
Abstract

Insights

Mitochondrial DNA (mtDNA) deletion disorders do not increase with maternal age. Affected women have a 1 in 24 risk of passing on mtDNA deletion disorders to their offspring.

Area of Science:

  • Genetics
  • Mitochondrial Biology
  • Human Disease

Background:

  • Pathogenic mitochondrial DNA (mtDNA) mutations affect at least 1 in 8000 individuals.
  • Currently, no effective treatments exist for mtDNA disorders, emphasizing the importance of disease prevention.
  • Many patients have a single pathogenic mtDNA deletion, but risk factors for new cases and recurrence are unknown.

Purpose of the Study:

  • To investigate the relationship between maternal age and the risk of unaffected mothers having children with mtDNA deletion disorders.
  • To determine recurrence risks of mtDNA deletion disorders among siblings and offspring of affected individuals.

Main Methods:

  • A multicenter study involving 226 families with a proband identified with a single mtDNA deletion.
  • Included patients with chronic progressive external ophthalmoplegia, Kearns-Sayre syndrome, or Pearson's syndrome.
  • Analyzed the association between maternal age and the risk of affected offspring, and calculated recurrence risks.

Main Results:

  • No correlation was found between maternal age and the risk of unaffected mothers having children with mtDNA deletion disorders.
  • None of the 251 siblings of index cases developed clinical features of mtDNA disease.
  • The risk of recurrence among offspring of affected women was 4.11% (approximately 1 in 24 births).

Conclusions:

  • The incidence of mtDNA deletion disorders is not influenced by maternal age, unlike nuclear chromosomal rearrangements.
  • Unaffected mothers are unlikely to have more than one child with an mtDNA deletion disorder.
  • The risk of affected women having clinically affected offspring is approximately 1 in 24, a higher risk than previously assumed.

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