Objective: To know more polymorphic changes in mitochondrial genome in Chinese.
Method: PCR and sequencing of the 16,569 bp long mtDNA of the white blood cell DNA were conducted on 4 Chinese children, 3 with Rett syndrome and one normal. PCR and Restriction endonuclease digest, including artificial created restriction site (ACRS), were done on 100 normal controls in the light of the 7 newly discovered single base substitution sites.
Result: Five point mutations, C298T, C638G, C3206T, A6323G and C6326T, neither appearing in MITOMAP database nor reported in literature before, were identified in Chinese people with the frequencies of 17.65%, 32.04%, 62.77%, 33.33% and 32.26%. Other two point mutations, C737T and C9860T, were found only in patients with Rett syndrome.
Conclusion: The five sequence changes newly found in mitochondrial genome of Chinese are de novo kinds of polymorphism.