Study of Triheptanoin for the Prevention of Hypoglycemia in Patients With Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)

Inclusion Criteria: * A diagnosis of MCAD deficiency with molecular confirmation. * Age criteria age ≥ 16 years * Able to perform and comply with study activities including overnight admission to the research unit at UPMC Children's Hospital Pittsburgh, placement of an IV catheter, and all blood draws. * Negative pregnancy test for all female subjects of child bearing age. Females of childbearning potential must agree to use a highly effective method of contraception, and males must agree not to father a child or donate sperm. True abstinence for the duration of the study will also be accepted. * Signed informed consent for subjects ≥ 18 years, or assent by subjects age 16-17 years with parental consent for underaged subjects. Exclusion Criteria: * Use of any investigational drug within 30 days of screening. * Active infection (viral or bacterial) or any other intercurrent condition as reported by the subject or noted on physical exam at screening. * Evidence of liver disease as defined by elevations of AST or ALT\> 1.5x ULN at screening * Any clinical or laboratory abnormality or medical condition that, at the discretion of the investigator, may put the subject at increased risk by participating in this study. * Pregnant, planning to become pregnant, breastfeeding or lactating females. * Diagnosis of pancreatic insufficiency or concomitant use of a pancreatic lipase inhibitor (e.g. Orlistat) which can interfere with absorption of triheptanoin * Subjects with type 1 or typ…