Approximately 70% of BB stakeholders view re-consent as necessary. This aligns with findings from international studies in which 73% of experts involved in human research protection supported re-consent for genetic research (Lemke et al. 2010). While re-consent respects participant autonomy (Wallace et al. 2016), challenges include the logistical burden and the potential discomfort of re-engaging participants.

Studies in Canada and the UK show that research participants feel more engaged when asked for re-consent (Master et al. 2013; van der Velden et al. 2023). However, concerns exist regarding administrative feasibility, costs, and participant burden. In this study, only 25% of BBs implemented re-consent, indicating significant challenges in its practical application.

Moreover, requiring re-consent at the age of consent can serve as a mechanism to promote public trust in research institutions. When individuals are actively given the opportunity to decide on the continued use of their samples and data, it enhances their sense of agency and may contribute to greater societal acceptance of biobanking practices. This aligns with discussions on dynamic consent models that emphasize transparency and ongoing participant engagement (Kaye et al. 2015).

In Japan, the continued use of samples and data in pediatric genomic research based on broad consent given by parents is commonly accepted, in accordance with guidance provided by national ethical guidelines. This acceptance typically applies only to biospecimens and information that were already collected prior to the child reaching adulthood. When such data or samples are used in ongoing or new research, it is customary to notify the public through the disclosure of study information and to provide an opportunity for opt-out, rather than seeking renewed individual consent. Cultural norms that emphasize family decision-making may support such practices, yet this approach may conflict with emerging standards of individual autonomy and informed consent.

Further illustrating these challenges, a semi-structured interview survey of 30 Australian young adults (18–34 years old) who were former pediatric oncology patients and had stored biospecimens revealed that 60% believed biobanking permission should be re-obtained in adulthood, yet 70% were unaware of their previously banked tissue (Rush et al. 2015). From a researcher’s perspective, arguments against re-consent include the impracticality of obtaining individual consent, high resource demands, and the concern that re-consent requests might cause undue distress to participants (Wallace et al. 2016). Given that only one-quarter of the BBs in this study had implemented re-consent, its widespread adoption remains a significant challenge.

Various alternative approaches to re-consent, such as opt-out notification and complete anonymization, have been proposed. However, each method presents challenges. Opt-out approaches raise concerns about the effectiveness of information dissemination, as previous studies suggest that participants strongly prefer explicit permission for the use of their genetic data (Ludman et al. 2010). On the other hand, complete anonymization removes the need for re-consent but also limits participants’ rights, such as withdrawing consent or receiving research results. Given Japan’s legal framework, anonymization alone may not fully meet ethical compliance requirements. In Japan, genomic data are classified as personal information under the Act on the Protection of Personal Information. the Ethical Guideline for Life Science and Medical Research Involving Human Subjects in Japan (2021) further emphasize the importance of data protection and the safeguarding of individual rights, even in research involving anonymized data. Consequently, complete anonymization does not necessarily exempt a study from ethical oversight. Comparative frameworks, such as the EU’s GDPR, highlight similar concerns, where pseudonymization still requires legal safeguards (Shabani and Borry 2018).

BB stakeholders emphasized that the most appropriate re-consent method depends on several factors, including the management status of samples and data, accessibility to participants, timing of re-consent, and the operational burden on BBs. To determine the most suitable approach, it is crucial to conduct surveys involving research participants, their proxies, and the public while continuously evaluating the necessity and feasibility of re-consent practices in Japan. Digital tools, such as secure web portals and mobile apps, are useful for promoting communication with participants and enabling re-consent and dynamic consent (Gesualdo et al. 2021; Lee et al. 2024). While these approaches have been adopted internationally, they have not yet been implemented in Japanese biobanks and remain a future direction.

Many respondents in this survey highlighted “discovering the causes of diseases and developing treatment/prevention methods” as key benefits of sharing pediatric genomic data. Similarly, a U.S. study involving 163 parents of infants found that those who participated in a clinical trial prioritized the “direct benefit for the child” significantly more than non-participating parents (Shah et al. 2018), a trend supported by multiple studies (Hoberman et al. 2013; Nathe et al. 2023). Some ethical concerns raised by stakeholders—particularly participants’ expectations of personal benefit—may reflect a phenomenon known as the ‘therapeutic misconception.’ This refers to the mistaken belief that participating in research will provide direct therapeutic benefits, even though the primary objective of research is to generate generalizable knowledge rather than to deliver clinical care (Appelbaum et al. 1987). In pediatric biobanking, such misconceptions may influence parental decision-making, especially when consent is motivated by hopes of discovering a cure or advancing treatments for their child. Moreover, altruism has been identified as the second most common motivation for participating in research after direct personal benefit (Nathe et al. 2023). Therefore, it is essential to clearly communicate that participation in research primarily contributes to broader societal benefits—such as the development of future treatments and preventive strategies for other children—rather than immediate clinical outcomes for the participant. Conversely, concerns about privacy and genetic discrimination were prominent. Over half of the respondents cited “the possibility of invasion of privacy,” while more than 40% mentioned risks of “discrimination and stigma.” A survey of 10,731 Japanese individuals, including cancer patients and their families, indicated that those with a personal or family history of disease were more concerned about genetic discrimination than healthy individuals (Ri et al. 2023). Another study of 1,760 parents of newborns who declined genomic research participation found that privacy and discrimination concerns influenced their decision (Genetti et al. 2019).

Genetic discrimination remains a global issue, with policies differing by country in terms of insurance enrollment, employment, and public awareness (Kim et al. 2021). In North America, concerns differ by race, nationality, and insurance systems (Hall et al. 2005; Prince & Marks 2021), whereas seven Asian countries, including Japan, report lower concerns in health insurance due to universal coverage (Kim et al. 2021). However, in Japan, younger generations are increasingly worried about genetic discrimination in employment, while concerns about marriage and pregnancy discrimination remain significant (Hishiyama et al. 2019). These findings suggest that in Japan, genomic research participation concerns extend beyond medical risks to social and economic implications. To mitigate these risks, measures should be implemented to prevent discrimination and enhance public literacy on genomic research.

Advances in genomic analysis have improved accuracy and expanded clinical applications. The American College of Medical Genetics and Genomics (ACMG) has identified actionable genes for clinical disclosure, including secondary findings. In Japan, the Tohoku Medical Megabank pilot study returned results on pathogenic variants for familial hypercholesterolemia, Lynch syndrome, and hereditary breast and ovarian cancers (Kawame et al. 2022; Ohneda et al. 2023). While genomic information can facilitate health management, it may also heighten anxiety and concerns about unexpected hereditary disease diagnoses. To ensure responsible data sharing, genetic experts should provide appropriate information and psychosocial support. In practice, re-consent is not only relevant at age thresholds but also when returning individual results with clinical significance. Such key decision points warrant renewed consent to ensure ongoing voluntary participation (Appelbaum et al. 2014). Given that many participants initially enrolled through parental consent, re-consent becomes increasingly vital in allowing individuals to make informed decisions about their genetic data. Genetic counselors can play a crucial role in re-consent processes by supporting participants in understanding genomic results and making informed decisions. Their involvement may enhance participant autonomy and reduce anxiety about unexpected findings.

Since the respondents of this study were just 21 BB stakeholders (response rate was approximately 50%), the results did not reflect all BBs in Japan. However, this study was a first step in the discussion on the pediatric genome data sharing among nationwide Japan BBs.