title: Mitochondrial insertion-deletion polymorphism: role in disease pathology.
abstract: OBJECTIVE
  Mitochondrial DNA (mtDNA) sequence variations are associated with a number of human diseases. The 9-bp repeat sequence, CCCCCTCTA, in the intergenic region of MTCO2 and MTTK genes of the mtDNA has been extensively used in phylogenic studies. The sequence has been reported to be polymorphic in south-east Asians in isolated cases of mt diseases. This is the first systemic study identifying the role of insertion-deletion polymorphism in human disease.
  
  
  RESULTS
  A total of 241 patients including those with cardiomyopathy, ataxias, and idiopathic neurological disorders along with 100 controls were screened; 2.9% of patients showed a single repeat (deletion) and 4.14% had three repeats (insertion), whereas all the controls had two repeats (normal).
  
  
  CONCLUSIONS
  This indicates that the 9-bp insertion-deletion repeat polymorphism plays a role in disease pathology, affecting the expression of the downstream genes of mtDNA and altering ATP generation.
authors.affiliation: Department of Genetics and Molecular Medicine, Kamineni Hospitals, L.B Nagar, Hyderabad, India.
authors.forename: Sreelatha
authors.initials: S
authors.lastname: Komandur
authors.forename: Sambasivan
authors.initials: S
authors.lastname: Venkatasubramanian
authors.forename: Ravindra Varma
authors.initials: RV
authors.lastname: Alluri
authors.forename: Pragna
authors.initials: P
authors.lastname: Rao
authors.forename: Prabhakar
authors.initials: P
authors.lastname: Rao
authors.forename: Qurratulain
authors.initials: Q
authors.lastname: Hasan
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000235:genetics*; D016022:Case-Control Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D008928:Mitochondria / Q000235:genetics / Q000473:pathology; D016254:Mutagenesis, Insertional; D009422:Nervous System Diseases / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012357:RNA, Transfer, Lys / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D020754:Spinocerebellar Ataxias / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D012357:RNA, Transfer, Lys; C117108:cytochrome C oxidase subunit II; D003576:Electron Transport Complex IV