Suzuki Toshihiro, Wada Yoichi, Mikami-Saito Yasuko, Kikuchi Atsuo, Kure Shigeo
Department of Pediatrics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8573, Japan.
Mol Genet Metab Rep. 2021 Dec 20;30:100834. doi: 10.1016/j.ymgmr.2021.100834. eCollection 2022 Mar.
Citrin deficiency belongs to a group of urea cycle disorders that can be identified during newborn screening by measuring citrulline, phenylalanine, methionine, and galactose levels. Early diagnosis of citrin deficiency is beneficial as disease-specific interventions such as permission of food preference and/or supplementation of medium-chain triglyceride can prevent metabolic decompensation. However, there are currently no laboratory tests for the diagnosis of citrin deficiency in routine clinical practice. Our retrospective study investigated the diagnostic characteristics of citrin deficiency during infancy at secondary newborn screening. The present study included 10 patients with citrin deficiency and 35 controls without the condition. The positive likelihood ratios for serum levels of blood urea nitrogen (BUN) levels were 6.8 at the first visit, 3.2 at age ≤ 60 days, and 17.5 at age ≤ 100 days. The serum BUN/creatinine ratio also showed a high positive likelihood ratio (3.9 at first visit, 16.0 at age ≤ 60 days, and 24.5 at age ≤ 100 days). Therefore, the serum BUN or BUN/creatinine ratio may help to identify patients with citrin deficiency during newborn screening. Further studies are required to confirm its diagnostic accuracy in a larger cohort and elucidate the underlying mechanisms involved.
瓜氨酸缺乏症属于一组尿素循环障碍疾病，可在新生儿筛查期间通过测量瓜氨酸、苯丙氨酸、蛋氨酸和半乳糖水平来识别。瓜氨酸缺乏症的早期诊断有益，因为特定疾病的干预措施，如允许食物偏好和/或补充中链甘油三酯，可以预防代谢失代偿。然而，目前在常规临床实践中没有用于诊断瓜氨酸缺乏症的实验室检测方法。我们的回顾性研究调查了婴儿期二次新生儿筛查中瓜氨酸缺乏症的诊断特征。本研究纳入了10例瓜氨酸缺乏症患者和35例无该病症的对照。首次就诊时血尿素氮（BUN）水平的血清阳性似然比为6.8，≤60日龄时为3.2，≤100日龄时为17.5。血清BUN/肌酐比值也显示出较高的阳性似然比（首次就诊时为3.9，≤60日龄时为16.0，≤100日龄时为24.5）。因此，血清BUN或BUN/肌酐比值可能有助于在新生儿筛查中识别瓜氨酸缺乏症患者。需要进一步研究以在更大队列中确认其诊断准确性并阐明其中涉及的潜在机制。
