Deranged Liver Function in a Neonate

[摘要] A 1-week-old female neonate was evaluated following an abnormal newborn screening (NBS)2 result. The child developed coagulopathy (prothrombin time, 37.9 s; reference interval, 9.7–12.2 s) and a conjugated hyperbilirubinemia (direct bilirubin, 0.9 mg/dL; reference interval, 0.0–0.6 mg/dL). Her α-fetoprotein (AFP) concentration was increased at 375000 ng/mL (age-related reference interval, 1480–58887 ng/mL). An abdominal ultrasound scan was concerning for a liver nodule. A urine sample was collected for organic acid analysis by GC-MS. The results are shown in Fig. 1.Fig. 1. Organic acids analysis of patient urine using GC-MS.Urine organic acids were extracted into ethyl acetate/ether and converted to trimethylsilyl (TMS) derivatives prior to analysis using a GC 6890N/MS 5975 system equipped with a DB-1 column (Agilent). PDA, protein design automation.This patient has tyrosinemia type I (TYR1) caused by deficiency of fumarylacetoacetate hydrolase [EC.3.7.1.2], which catalyzes the hydrolysis of fumarylacetoacetate at the final step of tyrosine metabolism. As a result of the enzyme block, …

[学科分类] 过敏症与临床免疫学