Impact of revised severity criteria on the acceptability of PGT-M for childhood-onset cancer predisposition syndromes: a survey of genetic professionals in Japan.

The scope of preimplantation genetic testing for monogenic disorders (PGT-M) in Japan, initially limited to severe childhood-onset diseases, appears to be expanding following the 2022 revision of the Japan Society of Obstetrics and Gynecology's definition of "severity." This study examines the impact of this definitional change on the acceptability of PGT-M by comparing attitudes of Japanese genetic professionals before and after the revision, focusing on three childhood-onset cancer predisposition syndromes: Li-Fraumeni syndrome (LFS), familial adenomatous polyposis (FAP), and neurofibromatosis type 1 (NF1). A two-phase survey was conducted in 2019-2020 and 2024 among clinical genetic specialists supervisors and certified genetic counselors. The survey explored views on PGT-M acceptability, the concept of "selection of life," awareness of the revised severity definition, and background factors influencing opinions. Among 382 respondents, LFS was most frequently judged acceptable for PGT-M, followed by FAP and NF1. Between the two phases, "unacceptable" responses declined, while "neither" increased. Those viewing PGT-M as "selection of life" were more likely to oppose it (r=-.293, p<.01). Genetic professionals in the pediatric field were more likely to consider PGT-M unacceptable (r=-.22, p<.01). These findings suggest that clinical experience, ethical perceptions, and institutional guidelines shape professional attitudes toward PGT-M. These findings have implications for genetic counseling practice and policy discussions surrounding the evolving scope of PGT-M. Ongoing dialogue and education are essential as eligibility criteria and societal values continue to evolve.