Participant eligibility for the study will be determined during a screening period lasting up to 45 days. In-clinic follow visits will occur over several days every 6 months for 2 years from baseline. Thereafter, annual telephone follow-up contact will be conducted for 2 additional years. Thus, the active study duration for each participant will be up to approximately 2 years and the total duration per participant will be approximately 4 years.~The study will be conducted in the United States and select sites outside the United States based on incidence data.
The purpose of the study is to prospectively and systematically collect standardized clinical information, to describe important features of the disease course of SURF1 deficiency. These include but are not limited to symptomatology, clinical course, and risk factors for severe disease and complications.