2010 Volume 10 Issue 2 Pages 65-70
All bilateral and 10–15 ％ of unilateral retinoblastomas are hereditary with a germline inactivating mutation of the RB1 gene. An early diagnosis increases a chance for eye and eyesight preservation. About half of newly diagnosed retinoblastoma cases in Japan visit National Cancer Center Hospital, in which 88probands and 74 relativeschose genetic tests from 1998 to March 2010. The tests typically consist of dHPLC（WAVE）analysis for the entire RB1 coding region followed by direct sequencing, direct sequencing of the RT-PCR products of all RB1 exons, Multiplex Ligation-dependent Probe Amplification （MLPA） and FISH. Pathogenic mutations were detected in 93 ％ for bilateral cases and unilateral cases with family history but 11 ％ for unilateral cases without family history. Because sensitivity is not sufficient for each single test, and detection of mosaicism and splicing aberration requires FISH and RT-PCR, respectively, the combination of multiple tests is necessary.
