迟发型鸟氨酸氨基酰转移酶缺乏症一例分析并文献复习

Report of a case with late-onset ornithine transcarbamylase deficiency with gas chromatography-mass spectrometry and DNA sequencing confirmation and literatures review

目的 探讨鸟氨酸氨基酰转移酶缺乏症（OTCD）相关临床特点及诊断、治疗经验.方法 报告1例安徽省儿童医院2014年收治的鸟氨酸氨基酰转移酶缺乏症患儿临床诊治疗经过,并结合国内外报道的鸟氨酸氨基酰转移酶缺乏症的资料进行文献复习.结果 （1）8岁男童,进食较多鸡蛋后,出现呕吐、意识模糊症状1d.既往有类似病史.血氨2 500μmol/L.疑诊OTCD,给予禁食、高热卡静脉输注、降血氨等治疗,患儿病情进行性加重,最终因脑疝、中枢性心血管功能衰竭而死亡.死亡后尿气相色谱-质谱、血浆氨基酸报告血瓜氨酸、精氨酸降低,尿乳清酸升高,OTC基因突变[OTCc.386G＞A p.（Arg129His）]确诊为OTCD.（2）总结近5年国内外数据库中检索到的明确诊断及有治疗结果的OTCD 65例,发病年龄在3d至49岁;40例有呕吐症状,32例有意识障碍.52例行血氨基酸、尿有机酸检查,均有血瓜氨酸、精氨酸降低,尿乳清酸升高;42例行OTC基因检查,均检测到OTC致病基因位于Xp21.1,致病基因均有基因突变,重复位点较少.55例国外患者资料中,存活53例,死亡2例.10例国内患者资料中,存活3例,4例死亡,3例失联.结论 OTCD常以呕吐、意识障碍起病,有血氨升高,可先临床诊断并治疗,确诊须通过尿气相色谱-质谱、血浆氨基酸检查以及基因检测结果.国内OTCD患者预后差可能与对此类疾病认识度不高有关.

Objective To discuss the clinical characteristics,diagnosis and treatment management of ornithine transcarbamylase deficiency （OTCD）.Method Data of the clinical diagnosis and treatment of a case with OTCD were analyzed,and the domestic and intemational literature was reviewed.Result （1） The case was a boy,8 years old; and the initial symptoms were vomiting and reduced consciousness for a day after eating a lot of eggs as previous similar history.The level of blood ammonia was 2 500 μmol/L.The patient was treated with fasting,high-calorie fluid intravenous infusion,reducing blood ammonia.However,the disease further aggravated and the patient died due to brain hernia and central cardiovascular failure.Finally,he was confirmed as OTCD through urine testing by gas chromatography-mass spectrometry,plasma amino acid examination （plasma arginine and citrullineurine reduced,orotic acid raised） and genetic testing （OTC c.386G 〉 A p.（Arg129His））.（2） Data of 55 case reports about diagnosis and treatment outcome including 65 OTCD cases＇ clinical data in domestic and abroad reports in nearly 5 years.Their ages ranged from 3 days to 49 years; the common symptoms were vomiting and encephalopathy; both urine tests were positive in 52 cases; pathogenic genes had less repeated loci and located at Xp21.1 in 42 cases detected by OTC gene test; all of which had gene mutation.Conclusion The acute onset OTCD begins with the symptoms of vomiting and unconsciousness,with rapid rise of blood ammonia level.OTCD may cause high mortality.