摘要目的:探讨新生儿蛋白C缺乏症（protein C deficiency，PCD）患儿的临床特征、诊断治疗和基因特点，提高临床对PCD的认识。方法:对首都儿科研究所附属儿童医院新生儿科收治的1例严重新生儿PCD患儿临床资料进行回顾性分析。以“婴儿”、“新生儿”、“蛋白C缺乏”、“蛋白质C缺乏”、“暴发性紫癜”和“newborn”、“neonate”、“protein C deficiency”、“purpura fulminans”为主题词，对中国知网、万方数据库、中国生物医学文献数据库、维普生物医学数据库、Pubmed、Embase、SCI数据库收录的文献进行检索，总结已报道的新生儿PCD临床特征和基因变异特点。结果:本例患儿为足月女婴，生后2 d逐渐出现血小板减少、颅内出血、皮肤多发暴发性紫癜、弥散性血管内凝血、腹腔出血、高血压、门静脉及髂静脉血栓、视网膜剥离等表现，蛋白C活性<10%。基因结果回报PROC基因存在复合杂合变异，父源c.314G>T（p.C105F）和母源c.1218G>A（p.M406I），ACMG变异评级均为疑似致病变异，符合常染色体隐性遗传模式。住院6周患儿家长放弃治疗离院。检索到临床资料相对完整的新生儿病例文献共25篇，涉及患儿29例，其中男18例，女11例；早产儿4例，足月儿25例；生后7 d内起病28例；主要临床特征为皮肤暴发性紫癜及脏器血栓；记录蛋白C结果22例，范围0~25%；记录PROC基因异常结果16例，复合杂合变异10例。有预后记录的患儿22例，11例死亡，其中9例在3个月内死亡，余均遗留严重智力运动发育障碍、癫痫及失明等后遗症。结论:新生儿期发病的PCD主要临床表现包括暴发性紫癜、弥散性血管内凝血、全身多脏器出血或血栓等，起病急、症状重、病情进展快，预后差、病死率高，蛋白C水平检测及PROC基因检测可明确诊断。

abstractsObjective:To study the clinical features, diagnosis, treatment and genetic characteristics of neonatal-onset protein C deficiency (PCD).Methods:The clinical data of a newborn patient with severe PCD admitted to our neonatal department was reviewed. Databases including CNKI, Wanfang Database, CMB, VIP database, PubMed, Embase and SCI database were searched using" infantile", " neonate ", "newborn", "protein C deficiency" and "purpura fulminans" as key words. Published cases of PCD were analyzed.Results:The patient was a full-term female infant who developed multiple symptoms within 2 days after birth. The symptoms included thrombocytopenia, intracranial hemorrhage, purpura fulminans (PF), disseminated intravascular coagulation (DIC), celiac hemorrhage, hypertension, portal and iliac vein thrombosis, purulent meningitis and retinal detachment. Protein C activity was less than 10%. Genetic tests showed compound heterozygous mutations c.314G>T (p.c105f) of paternal origin and c.1218G>A (p.m406i) of maternal origin in PROC gene. According to ACMG guidelines, the mutations were strongly suspected pathogenic variants and consistent with an autosomal recessive (AR) inheritance pattern. The patient was discharged after 6 weeks of treatment at parents' request of withdrawal. A total of 25 articles on 29 patients with relatively complete clinical data were retrieved, including 18 males and 11 females. 4 patients were preterm and 25 full-term. 28 patients showed symptoms within 7 days after birth. The common clinical features were cutaneous PF and splanchnic thrombi. 22 cases documented protein C activity and ranged from 0 to 25%. 16 patients had PROC gene abnormalities and compound heterozygous mutations were found in 10 patients. Among the 22 patients with prognostic data, 11 died (9 within 3 months after birth), the remaining survivors suffered from sequelae including severe intellectual motor development disorder, epilepsy and blindness.Conclusions:The main clinical manifestations of neonatal-onset PCD include PF, DIC, multi-organ hemorrhage and thrombus. The disease is acute and severe, with rapid progression, poor prognosis and high fatality rate. Protein C activity and PROC gene testing may help establish the diagnosis.