This will be a comprehensive, cross-sectional study conducted in approximately 60 individuals (or representative parents of patients) affected by ENPP1 deficiency and the acute form of ABCC6 deficiency. All study participants will complete the RSVP, PRO tools and upload a proof of disease form, followed by an interview conducted by a trained interviewer. It is estimated that each respondent will need up to 60 minutes for the entire process; 20 minutes to complete the RSVP, PRO tools and to upload proof of diagnosis of ENPP1 deficiency or the acute form of ABBC6 deficiency, and approximately 40 minutes to complete the interview and address any follow-up questions if needed.

