Liver Metabolic Functions in Patients With Citrin Deficiency and Healthy Subjects

Inclusion criteria for AACD patients are: * Subjects with citrin deficiency, confirmed by genetic analysis to carry pathogenic variant(s) in the SLC25A13 gene * Age from 18 years to 65 years inclusive * Male or female * Written informed consent has been given * Understands and is willing, able and likely to comply with study procedures and restrictions Inclusion criteria for healthy subjects are: * Age from 18 years to 65 years inclusive, and not more than five years younger or older than the specified paired participant from the AACD group * Same sex as the specified paired participant from the AACD group * Same ethnicity the specified paired participant from the AACD group * Written informed consent has been given * Understands and is willing, able and likely to comply with study procedures and restrictions Exclusion criteria for AACD patients are: * acute and chronic disease requiring treatment of any kind, other than his/her AACD * females who are pregnant or lactating or attempting to become pregnant * use of any medication which, in the opinion of the investigator, is likely to interfere with liver function Exclusion criteria for healthy subjects are: * carry any pathogenic variant in the SLC25A13 gene * current or recurrent disease that could affect the metabolic function of the liver * acute and chronic disease requiring treatment of any kind * females who are pregnant or lactating or attempting to become pregnant * use of any medication which, in the opinion of the investigator, is likely to interfere with liver function * weight loss ≥10% within 3 months before study screening * daily alcohol consumption of more than 2 standard-sized beer for men and more than 1 standard-sized beer for women, or the equivalent * BMI \> 30 kg/m2 * currently smoking \>1 cigarette daily * liver transplant recipients * type 1 and 2 diabetes * currently on a ketogenic diet * currently taking medium chain triglyceride (MCT) supplements