| Object 1. To detect the cytochrome oxidase (CO I, II) gene mutation which differs from the normal tissue in MDS patients. 2. To determine if the mutations suggest the existence of the "hot spot" reported in documents. 3. To find out unreported single-nucleotide- polymorphisms.Methods Eighteen MDS patients aged from 20 to 70 years old were brought into this study, including 2 cases with RA, 3 cases with RCMD, 7cases with RAEB, 5cases with RAEB-t/AML, and 1 case with MDS/MPD. The total DNA was extracted both from bone marrow cells and buccal cells of the same MDS patients separately. We designed a pair of primers to amplify a fragment with 528 base pair by PCR technique, which contained the "hot spot" of cytochrome oxidase (CO I, CO II) gene mutation based on the literature report. The PCR products were purified and sequenced. The results of sequence of CO I , CO II gene from MDS patients bone marrow cells were contrasted both with the standard from Gene Bank and with that from MDS patients buccal cells, and were analyzed if the mutation alsoexisted in normal somatic cells.Result We have found 3 single nucleotide changes in 528bp cytochrome oxidase gene fragment from 18 MDS patients. They were 7674 T->C, 7353 A->G, and the insert mutation of G at 7702. It needs to be testified further more due to the mutation was lain in primer region.Conclusions l.Our study fails to reveal the "hot spot" of mtDNA mutation, and does not support that cytochrome oxidase (CO I . II ) gene mutation plays a key role in MDS pathogenesis. The mutations previously reported may not be universal changes. It is probably a phenomenon just accompany with the disease. 2. Comparing and our data with foreigner's study, the difference may be due to the factors listed below: lack of subtype of RARS, race differences, and the region we selected in mtDNA. |
