摘要Cytogenetic analysis of eight cases of retinoblastoma patients was carried out to deter-mine the occurrence of chromosome aberrations and to identify consistently associated clinical abnormali-ties.Among the 80 cases,55 cases were unilateral,25 cases were bilateral.seventy patients had a posi-tive family history of Rb in 10 families.Normal chromosomes were found in 70 patients.Ten pati-ents showed abnormal karyotypes:two cases of 13q deletion,one case of mosaicism of 13q deletion,one case of translocation between chromosomes 13 and 15 with the interstitial deletion of 13q,one case of 47,xxy,three cases of pericentric inversion of hete-romorphic region of chromosome 9,two cases of pe-ricentirc inversion of chromosome Y.The patient who had the translocation between 13 and 5 with 13q deletion was found to have the characteristic midfacial appearance associated with 13q-deletion syndrome.