Abstract: Objective：To verify the maternal balanced reciprocal translocation t（22；22） in a pregnant woman and the partial trisomy 22q in her fetus, which detected by G banding in a local hospital, using the combined genetic techniques. Methods：G-banding， N-banding and FISH were performed in the pregnant woman and her fetus，and high-resolution G-banding and N-banding in parents of the pregnant woman. Results：Inherited from her mother，the pregnant woman had the karyotype of 46，XX，t（11；22）（q25；q13），22ps+. 22ps+ which was obviously a balanced reciprocal translocation with a pair of 22ps+ polymorphisms. A 22ps+ and a normal chromosome 11 in fetus were found to transmit from the pregnant woman，leading to a balanced karyotype in the fetus. Conclusions：The comprehensive analysis by using combined genetic techniques should be performed in fetus and family members to prevent errors in prenatal diagnosis.

Key words: Chromosome banding, Nucleolar organizer region, In situ hybridization, fluorescence, Polymorphism, single nucleotide, Nucleic acid hybridization