If the medical device is intended to treat serious or lifethreatening diseases, occurring in both adults and paediatric patients, for which there are currently no or limited therapeutic options, paediatric population may be included in the clinical investigation early, following assessment of initial safety data and reasonable evidence of potential benefit. In circumstances where this is not possible, lack of data has to be justified. (e) If the medical device has a potential for use in paediatric patient, paediatric studies may be conducted. These studies may be initiated at various stages of clinical development or after post-marketing surveillance in adults, if a safety concern exists. In cases where there is limited paediatric data at the time of submission of application, more data in paediatric patients would be expected after marketing authorization for use in children is granted. (f) Paediatric subjects are legally unable to provide written informed consent, and are dependent on their parents or legal guardian to assume responsibility for their participation in clinical investigation. Written informed consent shall be obtained from the parent or legal guardian. However, all paediatric participants shall be informed to the fullest extent possible about the study in a language and in terms that they are able to understand. Where appropriate, paediatric participants should additionally assent to enroll in the study. Mature minors and adolescents should personally sign and date a separately designed written consent form. Although a participant's wish to withdraw from a study shall be respected, there may be circumstances in therapeutic studies for serious or life-threatening diseases in which, in the opinion of the investigator and parent or legal guardian, the welfare of a pediatric patient would be jeopardized by his or her failing to participate in the study. In this situation, continued parental or legal guardian consent will be sufficient to allow participation in the study.