Correction to: Orphanet J Rare Dis (2021) 16:62 https://doi.org/10.1186/s13023-020-01666-4

Following the publication of the original article [1] it was brought to our attention that some of the authors are part of the Evidence Review Group for the England & Wales National Institute for Health and Care Excellence (NICE) and did not yet have permission to publish the case studies in this article, because final guidance has not been issued.

Any mentions to the case studies have, therefore, been removed from the original article, which has already been updated online.