Ethics Approval

This retrospective case series involving human participants was in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This research study was conducted retrospectively from data obtained for clinical purposes, with already signed informed consent for clinical studies. We consulted extensively with the Ethics Committee from our tertiary center who determined that our study did not need additional ethical approval.

Consent to Participate

Written informed consent was obtained from all patients or parent/guardian/relative of the patients included in the manuscript.

Consent for Publication

Not applicable.

Competing Interests

PYL receives royalty from UpToDate for a section on DADA2. We certify that other authors have no competing interests.