Footnotes

• Contributors AZ conceptualised and designed the study, acquired patient data, drafted the initial manuscript and approved the final manuscript as submitted. DE conceptualised and designed the study, acquired patient data, critically reviewed the manuscript, and approved the final manuscript as submitted. JL and HP acquired patient data, critically reviewed the manuscript and approved the final manuscript as submitted. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

• Competing interests None declared.

• Patient consent Obtained from the parents/guardian.

• Provenance and peer review Not commissioned; internally peer reviewed.