Albertine Donker

General Discussion 311 9 The translation of the above-mentioned legislation to daily practice is costly and time-consuming. Practical solutions, especially with regards to informed consent (IC) procedures that reasonably take account of the rights of the involved patients without interfering with the conduction of relevant research are urgently needed. This is of particular interest for minors, for which the procedure regarding participation in clinical research is even more complicated from a legal point of view. 46 Apart from biobanking, (virtual) networks with health care providers involved in the care for patients with complex and/or rare disorders that require concentrated knowledge and resources and highly specialized treatments, is crucial. The European Reference Network (ERN) EuroBloodNet, of which the RCID is a part, is a promising example of such collaboration. 41,47,48 Further developing this network will certainly benefit (European) patients with rare disorders, such as the genetic anemias addressed in this thesis. Reference values of serum hepcidin are required for children of all age groups from various origins As discussed earlier, our study on serum values of hepcidin in children ( Chapter 7 4 ) predominantly contained older children of Western-European descent; young children and children of non-Western European origin were underrepresented. Therefore, broadening the study population regarding children of different age groups and ethnic origins is essential in order to establish usable and widely applicable reference values of serum hepcidin and its ratio to the iron parameters ferritin and TSAT, which form the starting point of the diagnosis and treatment of iron disorders in childhood. Noticeably, our data on serum hepcidin values relative to indicators of body iron show evidence for a changing set point of iron handling during childhood. This point needs further exploration, preferably in prospective cohort studies that assess the course of serum hepcidin levels from fetal life until young adulthood in a healthy population. However, this will present a challenge since children who visit the clinic periodically for check-ups including blood tests are often diagnosed with chronic conditions that are known to affect serum hepcidin values by either organ dysfunction as liver- or renal impairment or by inflammation. Moreover, clinical research in children is challenging because of the stringent Dutch legislation applying to medical research in minors; at this point practical and workable guidelines are urgently needed for this purpose.