关键词: 新生儿疾病筛查, 甲基丙二酸血症, 出生后3~7天, C16:1-OH

Abstract: Objective To understand distribution characteristics of the concentration of relevant indicators in neonatal methylmalonic academia (MMA) screening by tandem mass spectrometry technology, and to evaluate the application value of 3-hydroxyhexadecenoyl carnitine (C16:1-OH) in the interpretation of MMA diseases, so as to provide basis for improving the positive predictive value of MMA screening and screening efficiency. Methods A total of 185 239 local newborns born between October 2013 and July 2019 were conducted MMA screening using tandem mass spectrometry technology.The levels of MMA disease-related indicators were compared among children in different gender, gestational age and birth weight groups.The initial screening levels were compared with re-examination indicator levels of confirmed samples. Results A total of 44 cases were diagnosed, 5 cases with simple type, 39 cases with combined type, and the overall prevalence was about 0.023 7%(44/185 239).Grouped by gender, gestational age and birth weight, free carnitine (C0), propionyl carnitine (C3), propionyl carnitine/free carnitine (C3/C0), propionyl carnitine/acetyl carnitine (C3/C2), C16:1-OH and methionine (MET) and other index concentration value distribution differences were statistically significant (P＜0.001).Compared with the results of initial screening, the level of C3/C2 in the re-examination samples was significantly higher (Z=5.10,P＜0.001), while the C16:1-OH level in the re-examination samples was significantly lower (Z=5.236, P＜0.001).The area under the ROC curve of the C16:1-OH indicator was 0.951 (95%CI: 0.914 - 0.987), and the weight index was approximately 15.46. Conclusions When screening MMA in neonates, medical staff are suggested give comprehensive interpretation based on the time of blood collection, birth weight and gestational age so as to reduce the positive rate of initial screening.The C16:1-OH indicator is helpful in the interpretation of MMA disease in the primary screening sample (blood sampling from 3 to 7 days after birth), and can effectively improve the positive predictive value and screening efficiency, thereby achieving early diagnosis, early treatment, and reducing the rate of disability.

Key words: neonatal disease screening, methylmalonic acidemia, 3~7 days after birth, C16:1-OH