Six cases for trisomy 12 were detected by one centromeric probe for 12.And del(13q14.3),del(11q23) were usually detected in normal karyotype.

• 12号着丝粒探针检出6例有+12；而且D13S272(13q14.；3)、ATM(11q23)缺失常发生在常规检测正常的核型。