探讨以反复肺炎为主要表现的原发性肉碱缺乏症(PCD)的临床特点。

选择2015年9月，因"发育落后9个月，反复重症肺炎5次，咳嗽、喘息3 d"，于河南中医药大学第一附属医院住院治疗的1例11个月龄女性PCD患儿为研究对象。其2～7个月龄时，因重症肺炎反复发作5次，入不同医院治疗。本次入院后，对患儿进行血常规、血生化等实验室检查、血液氨基酸及酯酰肉碱谱分析、尿有机酸分析、基因检测等，以确诊PCD；采取Gesell发育评估法评估患儿发育商(DQ)等。

①相关检测结果：本例患儿生长发育落后。2个月龄时发现血浆游离肉碱浓度为5.814 μmol/L(正常参考值为20.000～60.000 μmol/L)，酯酰肉碱谱正常，尿有机酸分析显示非酮症性二羧基酸尿症。患儿7个月龄时在上述病例收集医院复查血浆游离肉碱浓度为3.730 μmol/L；11个月龄时，因重症肺炎再次入上述病例收集医院治疗，发现肝功能损害，心肌酶谱异常，DQ为52.7，SLC22A5基因c.1400C>G(p.S467C)和c.632A>G(p.Y211C)2个杂合突变。②治疗与随访结果：给予左卡尼汀1 500 mg/d静脉滴注，同时给予抗感染治疗及营养支持，患儿病情改善，出院后长期口服左卡尼汀800 mg/d及采取其他支持措施治疗。患儿出院后4个月未再发生呼吸道感染，15个月龄时复查肝功能及心肌酶谱恢复正常，体格及神经系统发育接近正常儿童，DQ为63.9。

PCD患儿的临床表现缺乏特异性，血液酯酰肉碱谱分析、尿有机酸分析及基因检测结果有助于该病的早期诊断。早期、足量左卡尼汀治疗，可有效治疗及改善PCD患儿预后。

To investigate the clinical features of primary carnitine deficiency(PCD) with recurrent pneumonia as the main manifestation.

A eleven-month-old female patient hospitalized in Department of Pediatrics, the First Affiliated Hospital of Henan University of TCM in September 2015, was selected as study object. The chief complaint was " Mental and motor retardation for 9 months, recurrent severe pneumonia of 5 times, cough and wheezing for 3 d" . During 2- to 7-month-old, the infant had been treated in different hospitals for severe pneumonia for 5 times. After hospitalization in case collection hospital, the blood routine, blood biochemical laboratory tests, blood amino acids and acyl carnitine spectrum analysis, urine organic acid analysis and gene analysis were carried out to make a definite diagnosis of PCD.Use Gesell Developmental Scale to evaluate the development quotient(DQ).

①Related inspection results: this infant was characterized as growth and development retardation. The blood amino acids and acyl carnitine spectrum analysis tested at 2- month-old showed that, the free carnitine decreased significantly to 5.814 μmol/L(normal reference value is 20.000-60.000 μmol/L), and the acylcarnitine spectrum was normal. The urine organic acid analysis suggested non-ketosis second carboxyl aciduria. Free carnitine was as low as 3.73. μmol/L when 7-month-old in case collection hospital. When 11-month-old, this infant was treated in case collection hospital because of severe pneumonia and the examinations showed that: The patient has hepatic functional lesion and abnormal myocardial enzyme spectrum, and the DQ of Gesell Developmental Scale was 52.7, then the gene sequencing analysis revealed two heterozygous mutations which included a c. 1400C>G(p.S467C) and a c. 632A>G(p.Y211C)of SLC22A5 gene, ②Treatment and follow-up results: the infant was medicated with L-carnitine in the dose of 1 500 mg/d intravenous infused, meanwhile the anti-infective and supportive treatment were carried out. After disease condition improved, she was treated long-term with L-carnitine 800 mg/d orally and other support treatment. No more respiratory infections happened 4 months after release from hospital and the reexamination of liver function and myocardial enzyme spectrum were normal, and the developmental level of body build and nervous system were almost as normal child. The DQ of Gesell Developmental Scale was 63.9.

The clinical manifestations of PCD are not specific, and blood acyl carnitine spectrum analysis, urinary organic acid analysis and gene sequencing analysis are helpful for the early diagnosis of PCD. The sufficient quantities of L-carnitine medicated timely can treat it effectively and improve the prognosis.