Citrin deficiency develops in different symptomatic periods from the neonatal period to adulthood. Some infantile patients are diagnosed by newborn mass screening or symptoms of neonatal intrahepatic cholestasis caused by citrin deficiency, some patients in childhood may develop hepatopathy or dyslipidemia as failure to thrive and dyslipidemia caused by citrin deficiency, and some adults are diagnosed after developing adult-onset type 2 citrullinemia (CTLN2) with hyperammonemia or encephalopathy. A diagnosis is needed before the development of severe phenotypic CTLN2 but is often difficult to obtain because newborn mass screening cannot detect all patients with citrin deficiency, and undiagnosed patients often appear healthy in childhood. There are only a few reports that have described patients in childhood. To explore the clinical features of undiagnosed patients with citrin deficiency in childhood, we studied 20 patients who were diagnosed after the first year of life. Of these patients, 45% experienced hypoglycemic attacks in childhood. The acetoacetic acid level during hypoglycemic attacks was lower than expected. Growth failure at diagnosis (45%) was also noted. From the patients' history, fat- and protein-rich food preferences (80%), a low birth weight (70%), and prolonged jaundice or infantile hepatopathy (40%) were identified. To diagnose citrin deficiency in childhood, we should ask about food preferences and a history of infantile hepatopathy for all children with severe hypoglycemia or growth failure and consider the genetic test for citrin deficiency if the patient has characteristic food preferences or a history of infantile hepatopathy.

中文翻译：

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低血糖发作和生长障碍是 1 岁后 citrin 缺乏症最常见的表现

Citrin 缺乏症在从新生儿期到成年期的不同症状时期发展。一些婴儿患者通过新生儿大规模筛查或因 citrin 缺乏症引起的新生儿肝内胆汁淤积症状被诊断，一些儿童期患者可能发展为肝病或血脂异常，因为 citrin 缺乏症引起的发育迟缓和血脂异常，一些成人在成人发病后被诊断伴有高氨血症或脑病的 2 型瓜氨酸血症 (CTLN2)。在出现严重表型 CTLN2 之前需要进行诊断，但通常很难获得诊断，因为新生儿大规模筛查无法检测到所有 citrin 缺乏症患者，并且未确诊的患者通常在儿童时期看起来很健康。只有少数报道描述了儿童时期的患者。为了探索儿童时期未确诊的 citrin 缺乏症患者的临床特征，我们研究了 20 名在出生后第一年被确诊的患者。在这些患者中，45% 在儿童时期经历过低血糖发作。低血糖发作期间的乙酰乙酸水平低于预期。还注意到诊断时生长失败（45%）。根据患者的病史，确定了富含脂肪和蛋白质的食物偏好 (80%)、低出生体重 (70%) 和长期黄疸或婴儿肝病 (40%)。为了诊断儿童时期的 citrin 缺乏症，