Department of Pediatrics;
Jinshan Hospital;
Fudan University;
Department of Pathology and Laboratory Medicine;
Cincinnati Children's Hospital Medical Center;
The Center for Pediatric Liver Diseases;
Children's Hospital of Fudan University;
Department of Pediatrics;
Shanghai Medical College of Fudan University;
Δ4-3-oxosteroid-5β-reductase; deficiency; Mass; spectrometry; Bile; acid; synthesis; disorder; Chenodeoxycholic; acid; Ursodeoxycholic; acid;