Abstract
Context
Citrin-deficient infants present neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), which resolves at 12 months. Thereafter, they have normal liver function associated with hypercholesterolemia, and a preference for lipid-rich carbohydrate-restricted diets. However, some develop adult-onset type II citrullinemia, which is associated with metabolic abnormalities.
Objectives
To identify the causes of hypercholesterolemia in citrin-deficient children post-NICCD.
Design and Setting
We determined the concentrations of sterol markers of cholesterol synthesis, absorption, and catabolism by liquid chromatography–electrospray ionization–tandem mass spectrometry and evaluated serum lipoprotein profiles.
Subjects
Twenty citrin-deficient children aged 5 to 13 years and 37 age-matched healthy children.
Intervention
None.
Main Outcome Measures
Relationship between serum lipoproteins and sterol markers of cholesterol metabolism.
Results
The citrin-deficient group had a significantly higher high-density lipoprotein cholesterol (HDL-C) concentration than did the control group (78 ± 11 mg/dL vs 62 ± 14 mg/dL, P < 0.001), whereas the two groups had similar low-density lipoprotein cholesterol and triglyceride concentrations. The concentrations of markers of cholesterol synthesis (lathosterol and 7-dehydrocholesterol) and bile acids synthesis (7α-hydroxycholesterol and 27-hydroxycholesterol) were 1.5- to 2.8-fold and 1.5- to 3.9-fold, respectively, higher in the citrin-deficient group than in the control group. The concentration of 24S-hydroxycholesterol, a marker of cholesterol catabolism in the brain, was 2.5-fold higher in the citrin-deficient group. In both groups, the HDL-C concentration was significantly positively correlated with that of 27-hydroxycholesterol, the first product of the alternative bile acid synthesis pathway.
Conclusions
HDL-C and sterol marker concentrations are elevated in citrin-deficient children post-NICCD. Moreover, cholesterol synthesis and elimination are markedly enhanced in the liver and brain of citrin-deficient children.
Molecular diagnosis of pediatric patients with citrin deficiency in China: SLC25A13 mutation spectrum and the geographic distribution
