Wada Yoichi, Arai-Ichinoi Natsuko, Kikuchi Atsuo, Sakamoto Osamu, Kure Shigeo
Department of Pediatrics, Tohoku University School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, Miyagi, 980-8574, Japan.
Tohoku Medical Megabank Organization, 2-1, Seiryomachi, Aobaku, Sendai, Miyagi, 980-8573, Japan.
BMC Pediatr. 2020 Sep 22;20(1):444. doi: 10.1186/s12887-020-02349-6.
Citrin deficiency (CD) is a recessive metabolic disease caused by biallelic pathogenic variants in SLC25A13. Although previous studies have reported ketosis in CD, it was observed at the time of euglycemia or mild hypoglycemia. Blood ketone levels concomitant with symptomatic or severe hypoglycemia in CD have not been a topic of focus despite its importance in identifying the etiology of hypoglycemia and assessing the ability of fatty acid utilization. Herein, we describe a patient with CD who had repeated episodes of hypoglycemia with insufficient ketosis.
A 1-year-old boy with repetitive hypoglycemia was referred to us to investigate its etiology. The fasting load for 13 h led to hypoketotic hypoglycemia, indicating the possibility of partial β-oxidation dysfunction. A genetic test led to the diagnosis of CD. The hypoglycemic episodes disappeared after switching to a medium-chain triglyceride-containing formula.
This case report suggests that symptomatic or severe hypoglycemia in patients with CD could be associated with relatively low levels of ketone bodies, implying that β-oxidation in these patients might possibly be partially disrupted. When encountering a patient with hypoglycemia, clinicians should check blood ketone levels and bear in mind the possibility of CD because excessive intravenous administration of glucose can cause decompensated symptoms in patients with CD as opposed to other disorders presenting with hypoketotic hypoglycemia, such as fatty acid oxidation disorders. Further studies in a large-scale cohort are warranted to confirm our speculation.
瓜氨酸缺乏症（CD）是一种由SLC25A13双等位基因致病性变异引起的隐性代谢疾病。尽管先前的研究报道了CD患者出现酮症，但这种情况是在血糖正常或轻度低血糖时观察到的。尽管血酮水平在识别低血糖病因和评估脂肪酸利用能力方面具有重要意义，但CD患者出现症状性或严重低血糖时的血酮水平尚未成为关注焦点。在此，我们描述了一名患有CD的患者，该患者反复出现低血糖且酮症不足。
一名1岁反复出现低血糖的男孩被转诊至我院以调查病因。13小时的禁食负荷导致低酮性低血糖，提示存在部分β-氧化功能障碍的可能性。基因检测确诊为CD。改用含中链甘油三酯的配方奶后，低血糖发作消失。
本病例报告提示，CD患者的症状性或严重低血糖可能与酮体水平相对较低有关，这意味着这些患者的β-氧化可能部分受损。遇到低血糖患者时，临床医生应检查血酮水平，并牢记CD的可能性，因为与其他出现低酮性低血糖的疾病（如脂肪酸氧化障碍）不同，过度静脉输注葡萄糖会导致CD患者出现失代偿症状。有必要在大规模队列中进行进一步研究以证实我们的推测。
