Neonatal cholestasis with increased 3β-monohydroxy-Δ5 bile acids in serum and urine: Not necessarily primary oxysterol 7α hydroxylase deficiency

► Primary oxysterol 7α-hydroxylase (CYP7B1) deficiency is rare genetic disorders. ► Detected cholestenoic acid is important for diagnosis of CYP7B1 deficiency. ► Detected 27-hydroxycholesterol is also important for diagnosis of CYP7B1 deficiency. ► Patient with elevated 3β-monohydroxy-Δ5 bile acids is not necessarily CYP7B1 deficiency.