A Case of Increased C5-OH Acylcarnitine

[摘要] A 12-day-old male infant was brought to metabolism clinic to follow up an abnormal newborn screening result. The screening laboratory reported a 3-hydroxyisovalerylcarnitine (C5-OH)2 concentration of 170 μmol/L (reference cutoff value, <10 μmol/L). The child was born at term following an uneventful pregnancy. He was breastfeeding and developing normally with no concerns. A urine sample was collected for organic acid analysis by GC-MS. The results are shown in Fig. 1.Fig. 1. Organic acid analysis of patient urine using GC-MS.Urine organic acids were extracted into ethyl acetate/ether and converted to TMS derivatives prior to analysis using a GC 6890N/MS 5975 system equipped with a DB-1 column (Agilent). IS, internal standard.There are a total of 7 separate conditions that may result in an increased C5-OH concentration by acylcarnitine analysis using tandem mass spectrometry (MS/MS). Because organic acid analysis by GC-MS is …

[学科分类] 过敏症与临床免疫学