[Genetics of retinoblastoma].

Recent advancement of molecular genetics has enabled us to perform presymptomatic prediction for hereditary retinoblastoma, based on RB gene diagnosis. We used PCR combined with SSCP and heteroduplex analysis to screen leukocyte DNA, exon by exon, in patients with bilateral retinoblastoma. Germline mutations were detected in the 22 of the 33 cases, and, in 16 cases, the mutations were identified by sequencing. Among 2 families with those hereditary retinoblastoma presymptomatic prediction by the method described above was applied for 2 newborn babies, resulting in both success. It is expected that gene diagnosis will be applied for not only bilateral but also unilateral cases for genetic counseling.