[Five de novo forms of polymorphisms first found in Chinese mitochondrial genome].

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.