Protect\_Child\_101 is an observational study to be performed in children that have undergone a liver or renal transplant.
The aim of this study is to analyse small variations in the genetic material (DNA) of transplanted children. The investigators will also study a type of chemical 'marks' called methylations, which do not change the DNA itself, but can affect how it functions. These marks can influence how certain diseases develop or how the body responds to transplantation.
Specifically, investigators seek to discover:
* Whether there are genetic or epigenetic (methylation) alterations that may explain why some children develop serious diseases that require transplantation. * If these alterations can help us predict possible complications after transplantation, such as organ rejection, infections, organ failure, cancer development.
Within this study, data from the child's medical history will be collected. The data to be collected are demographic data (gender, age, ethnicity), clinical data, personal and family history possibly related to his/her disease, course and evolution of the disease, and complementary and laboratory examinations collected from his/her clinical history.
The only non-routine tests to be performed will be the genomic and methylomic tests. Nevertheless, these determinations will be performed on samples obtained during the child's routine care. No extra intervention is planned as part of this study.
Samples and clinical data will be collected at different time points after transplantation. Schematically, collection is planned for months 0, 1, 3, 6, 12 and 24 post-transplant. In addition to these pre-established points, comprehensive data collection will be attempted when the child suffers a relevant clinical event, e.g. infection, treatment toxicity, organ rejection (post-transplant complication).
● Paediatric patients (6 months to 18 years old) with liver or kidney transplant.
For the retrospective cohort, only patients within the first 5 years after transplantation will be included.
Patients and/or parents agreeing to participate in the study and provide consent for the obtention of clinical data and samples for genomic and methylomic analysis and the use of the information according to the protocol.
Patients that are not being followed up in the clinical site.
Subjects alternating between different clinical sites. Subjects/Tutors that don't understand the informed consent form.
Subject or their legally authorized representative does not sign the informed consent document.
Re-transplantation or AB0-incompatible transplantation.