Study to Evaluate the Use of Triheptanoin in Patients With Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)

Participation in the study will require four outpatient visits at the Clinical and Translational Research Center at the UPMC Children's Hospital of Pittsburgh (also called the PCTRC). The total length of the study participation is approximately 8 weeks. Participants will come in for a screening visit (Visit 1) to where they will undergo some lab work testing to confirm they are eligible for the study. If it's determined that they are eligible, they will undergo training on the use of a continuous glucose monitor (CGM). They will be sent home and asked to wear the CGM for the next 10 days. This 10-day period is considered the run-in period. Following the run-in period, participants will return to the site (Visit 2) in a fasting state. Fasting labs will be drawn, then the participant will be provided with a meal and they will then be dosed with triheptanoin. Following the dose of triheptanoin, the participant will be sent home with instructions on how to titrate (increase) the dose of triheptanoin over the next 28 days. Following the 28 day dose titration period, the participant will return to the site (Visit 3) in a fasting state. Fasting labs will be drawn, then the participant will be provided with a meal and then will then be dosed with triheptanoin Following the dose of ACER-001, the participant will be sent home with continuous glucose monitoring and will be asked to log their triheptanoin doses as well as overnight fasting times. Triheptanoin doses will be weight-based with the maximum dose being 1.0 gm/kg daily divided into 3 or 4 doses. Participants will be asked to return approximately 2 weeks later for Visit 4 to complete the same procedures outlined for Visit 3. Study staff will contact the participant by phone approximately 1 week after Visit 4 to follow up on any adverse events. All study procedures will be done at no cost to the participants.