探讨丙酮酸激酶缺乏症(PKD)患儿的临床与基因检测特点。

选择2016年4月7日，因"发现贫血2^＋个月"，于成都市妇女儿童中心医院接受治疗的1例PKD男性患儿为研究对象。回顾性分析其临床病例资料，包括本次住院情况、确诊经过及随访情况。在知情同意情况下，采集患儿及其父母外周血，采用疾病相关基因目标序列捕获和二代测序技术，筛选患儿及其父母基因突变类型，再采用Sanger法测序进行验证。以"丙酮酸激酶""溶血性贫血""hemolytic anemia""gene sequencing"等为关键词，检索国内外相关数据库，对建库至2019年1月各数据库中，关于PKD并有基因检测结果的文献进行复习。本研究符合2013年修订的《世界医学协会赫尔辛基宣言》。

①本例患儿此次入院年龄为2^＋个月，目前对其随访至2岁11个月。其主要临床表现：生后即出现严重黄疸，多次血常规检查均提示重度贫血、网织红细胞比例明显升高，提示溶血性贫血。实验室检查排除其葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症、地中海贫血等其他溶血性贫血相关疾病可能。针对初诊"自身免疫性溶血性贫血"的激素治疗无效，故临床考虑本例患儿为PKD，但是丙酮酸激酶(PK)活性检测结果正常。②基因检测结果：患儿父亲PKLR基因第10外显子c.1437-1G>A突变，患儿母亲PKLR基因第6外显子c.848T>C突变。患儿存在上述2处杂合突变，分别遗传自其父母。其中，患儿及其父亲共同存在的基因异常信息，在线人类孟德尔遗传数据库中尚未见收载。结合临床表现、实验室检查及基因检测结果，对患儿的PKD诊断明确。③PKD相关文献检索结果显示：PKD临床表现多样，并且PK活性受很多因素影响，因此迄今诊断并报道的PKD病例数较少。目前，我国已报道并且有基因检测结果的PKD患者共计12例(包括本例患儿)，其基因检测结果均为PKLR基因突变，83.3%(10/12)为杂合突变；75.0%(9/12)PK活性检测结果为正常，58.3%(7/12)为输血依赖，58.3%(7/12)出现肝和(或)脾大，25.0%(3/12)伴胆石症。

部分PK活性正常的PKD患者，可通过基因检测明确诊断。

To investigate the clinical and gene detection characteristics of children with pyruvate kinase deficiency (PKD).

A PKD boy with chief complaint of " anemia for 2⁺ months" who was admitted to Chengdu Women′s and Children′s Central Hospital on 7 April 2016, was chosen as research object. The clinical data of PKD child were analyzed retrospectively, including the hospitalization situation of this admission, diagnosis process and follow-up. In the case of informed consent, peripheral blood samples were collected from PKD boy and his parents to screening gene mutations of them through disease related gene target sequence capture and second-generation sequencing technology. Then these gene mutations were verified by method of Sanger sequencing. With key words of " pyruvate kinase" and " hemolytic anemia" in Chinese, and " hemolytic anemia" " gene sequencing" in English etc., the literature of PKD with gene detection results were collected from relevant domestic and foreign databases from construction to January 2019, then reviewed the relevant data. The study was in line with World Medical Association Declaration of Helsinki revised in 2013.

①The child was admitted to hospital at age of 2⁺ months and up to now he was age of 2 years and 11 months, and had been followed up for more than 2 years. The main clinical manifestations of him were as follows: he appeared serious jaundice shortly after birth, results of blood routine examinations showed severe anemia, reticulocyte proportion increased obviously for many times, and it was suggested that hemolytic anemia should be diagnosed. His relative laboratory test results excluded glucose-6-phosphate dehydrogenase (G6PD) deficiency, Thalassemia anemia and other types of hemolytic anemia related diseases. Because treatment of " autoimmune hemolytic anemia" by glucocorticoid was not effective, the child was considered PKD. However, the test result of pyruvate kinase (PK) activity was normal. ②The results of gene tests: pyruvate kinase liver and RBC (PKLR) gene of his father was c. 1437-1G>A mutation in exon 10, and PKLR gene of his mother was c. 848T>C mutation in exon 6, respectively. Both sites and types mutations of PKLR gene from his parents were detected in the child. Both genetic abnormalities in the child and his father were not reported in Online Mendelian Inheritance in Man yet. According to clinical manifestations, laboratory examinations and genetic testing results, diagnosis of PKD of this child was confirmed. ③The PKD related literature search results showed that due to diverse clinical manifestations of PKD and PK activity was affected by many factors, a few cases of PKD had already been reported. A total of 12 PKD patients (included this child) with gene test results in China were reported, and all of them were PKLR gene mutation. Among 12 PKD patients, the heterozygous mutation was 83.3% (10/12), proportion of normal PK activity was 75.0% (9/12), proportion of blood transfusion dependence was 58.3% (7/12), 58.3% (7/12) of patients had hepatomegaly and (or) splenomegaly and 25.0% (3/12) of patients had cholelithiasis.

Some PKD patients with normal PK activity could be diagnosed by gene test.