Peripheral blood karyotype analysis
Chromosome analysis was performed on routinely cultured peripheral blood lymphocytes as described previously[12]. Briefly,the sections were treated with trypsin using standard techniques, the slides were Giemsa stained and then G-banding analysis was performed. Add colchicine 4 hours before cytology preparation. For each sample, at least 20 cells from two independent cultures were used for microscopic observation and analysis in metaphase.