RB1 genetic testing as a clinical service: A follow-up study

Background Genetic testing for inherited predisposition to diverse cancers has recently become available as a clinical service. We conducted a follow- up study of the initial series of US families who underwent RBI genetic tes ting to evaluate long-term effects of the service. Procedure. We enrolled 5 2 of 71 eligible families who responded to a follow-up study questionnaire administered 3-10 years after receipt of their RBI results. Each family had one proband with unilateral, non-familial retinoblastoma, which is associa ted with a 12% pre-test probability of hereditary retinoblastoma. RBI testi ng identified germline RBI mutations in five patients, lowered the carrier probability to 2% in 21 patients, and did not substantially modify the carr ier probability in the remaining 26. Results. Diverse medical specialists o ffered and arranged for RBI testing, and their recommendation was the most influential factor in the decision to be tested, Pre-test counseling was pr ovided by ophthalmologists (30), oncologists (11), and geneticists and gene tic counselors (11). Most respondents, regardless of test result, were sati sfied and perceived gains from their genetic testing, Based on small number s, families with reduced likelihood of hereditary retinoblastoma reported m ore positive outcomes. Parents of RBI carriers were more likely to seek med ical services, worry, and decide against having more children. Conclusions. This study demonstrates the feasibility of follow-up studies of families w ho had genetic testing. Results from Our small series suggest that genetic information and counseling are important components of RBI clinical genetic testing, and long-term adverse effects of testing are uncommon. Med Pediat r Oncol 2001;37:372-378. (C) 2001 Wiley-Liss, Inc.