**5. Conclusions**

From the largest genotype–phenotype cohort of pediatric patients with HHT to date, we demonstrate that organ involvement and associated genotype-phenotype correlations in children with HHT are similar to those previously described in the adult population. Specifically, the *ENG* genotype is associated with pulmonary AVMs and brain VMs in children with HHT. Moreover, pediatric patients can present with a combined phenotype, with both pulmonary AVM and brain VM, which is also associated with the *ENG* genotype. Our results highlight the importance of organ VM screening in pediatric patients with HHT.

**Author Contributions:** Conceptualization, A.K., G.A.L., A.J.W., D.C., and M.E.F.; Data curation, The Brain Vascular Malformation Consortium HHT Investigator Group; Formal analysis, A.K. and M.E.F.; Investigation, A.K., G.A.L., A.J.W., D.C., M.M.C., F.R., J.M., K.W., J.R.G., D.L., K.H., J.P., J.P.M., H.K., M.T.L., and M.E.F.; Methodology, A.K., G.A.L., and M.E.F.; Project administration, H.K., M.T.L., and M.E.F.; Supervision, M.F.; Writing—original draft, A.K., G.A.L., A.J.W., D.C., and M.F.; Writing—review and editing, A.K. and M.E.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** The Brain Vascular Malformation Consortium (U54NS065705) is a part of the NCATS Rare Diseases Clinical Research Network (RDCRN) and is supported by the RDCRN Data Management and Coordinating Center (DMCC) (U2CTR002818). RDCRN is an initiative of the Office of Rare Diseases Research (ORDR), NCATS, funded through a collaboration between NCATS and NINDS. M.E.F. was also supported by the Nelson Arthur Hyland Foundation and Li Ka Shing Knowledge Institute.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
