中、短链酰基辅酶A脱氢酶缺乏症患儿临床特点分析及基因突变研究

中、短链酰基辅酶A 脱氢酶缺乏症属脂肪酸β 氧化障碍疾病,其基因突变可导致中、短链脂肪酸无法进入线粒体进行氧化供能,引起多器官功能异常。本研究对2 例临床表现为低血糖合并代谢性酸中毒的患儿进行血酰基肉碱及尿液有机酸分析,同时对患儿及其父母进行基因突变检测。家系1 患儿,男,3 d,出生后因新生儿窒息、吸奶无力、嗜睡住院治疗。血酰基肉碱谱提示中链酰基肉碱（C6~C10）升高,其中辛酰肉碱（C8）3.52 μmol/L（参考值0.02~0.2 μmol/L）;尿有机酸分析未见明显异常;Sanger 测序发现ACADM 基因7 号外显子已报道纯合突变c.580A>G（p.Asn194Asp）。家系2 患儿,女,3 个月,因咳嗽伴反复发热10 余天住院治疗。血酰基肉碱谱提示血丁酰肉碱（C4）1.66 μmol/L（参考值0.06~0.6 μmol/L）;尿有机酸分析提示乙基丙二酸55.9（参考值0~6.2）;Sanger 测序发现ACADS 基因已报道纯合突变c.625G > A（p.Gly209Ser）。研究结果提示对不明原因代谢性酸中毒及低血糖患儿应进行遗传代谢病筛查,通过家系ACADM、ACADS 基因分析,将有助于中、短链酰基辅酶A 脱氢酶缺乏症的诊断。     

全羧化酶合成酶缺乏症1 例临床及基因分析

目的探讨全羧化酶合成酶缺乏症的临床及基因诊断。方法回顾分析1例罕见的全羧化酶合成酶缺乏症患儿的临床及基因资料。结果男性患儿,出生后即发育落后,3月龄开始接受康复治疗;5月龄因反复呼吸道感染查尿有机酸谱,3-羟基丙酸、丙酮酸、3-甲基巴豆酰甘氨酸、甲基巴豆酰甘氨酸浓度增高,血氨基酸及肉碱谱、3-羟基异戊酰肉碱显著增高,伴游离肉碱降低;基因分析证实HCS基因外显子区域存在c.1648GA、c.1544GA杂合突变,确诊为全羧化酶合成酶缺乏症。其中,c.1544GA为新生突变。经口服生物素、左卡尼汀治疗后,患儿病情逐渐好转。随访至8月龄,智力运动发育明显进步。结论全羧化酶合成酶缺乏症临床起病缓慢,症状隐匿,可通过代谢筛查及HCS基因分析确诊。     

异戊酸血症一例临床及异戊酰辅酶A脱氢酶基因突变研究

目的 了解异戊酸血症患儿的临床、实验室特点以及异戊酰辅酶A脱氢酶(IVD)基因突变情况.方法 对1例异戊酸血症患儿的病史、实验室检查以及血串联质谱和尿气相色谱质谱结果进行了分析,对IVD基因12个外显子及两端内含子行PCR扩增和DNA测序,限制性内切酶片段长度多态性分析c.466G＞C(G127A)新突变.结果 患儿男,2岁7个月,生后3 d起出现呕吐和酸中毒,行幽门切开术后仍反复呕吐,伴有酸中毒发作,智力发育明显落后.血串联质谱分析显示C5酰基肉碱水平增高至12.89μmol/L,尿气相色谱质谱分析显示异戊酰甘氨酸明显升高,临床诊断为异戊酸血症.IVD基因DNA测序显示,患儿存在复合杂合突变:c.149G＞A(R21H)和c.466G＞C(G127A),c.466G＞C(G127A)突变在IVD基因第5外显子上,是以往未报道的新突变.结论 报道1例异戊酸血症,新生儿期发病,反复呕吐,酸中毒和智力落后,血C5酰基肉碱明显升高,尿中有异戊酰、甘氨酸大量排出,基因诊断发现1个IVD基因新突变.     

上呼吸道感染患儿口服尼美舒利后发生瑞氏综合征及猝死样症状

患儿，男，6岁3个月，2个月前因上呼吸道感染、发热，父母参照说明书予以尼美舒利口服，半小时后抽搐，呼吸心跳骤停，急诊检查发现低酮性低血糖，代谢性酸中毒，血清转氨酶及肌酶显著升高，肾功能受损。经积极复苏治疗后患儿意识及生命体征恢复，但是智力、运动严重倒退。患儿血液游离肉碱降低，中长链酯酰肉碱增高，尿液戊二酸、3-羟基戊二酸、异戊酰甘氨酸、乙基丙二酸等增高，提示多种酯酰辅酶A脱氢酶缺乏症。经维生素B₂、左卡尼汀、苯扎贝特等治疗后患儿病情逐渐好转，3个月后复查生化指标恢复正常。患儿ETFDH基因存在复合杂合突变，c.341G > A（p.R114H）为已知突变（来自母亲），c.1484C > G（p.P495R）为未报道的新突变（来自父亲）。患儿最终确诊为多种酰基辅酶A脱氢酶缺乏症，因发热服用尼美舒利诱发急性代谢危象，导致瑞氏综合征、猝死样发作。遗传代谢病是导致瑞氏综合征、猝死的一组主要病因，生化及基因分析是识别潜在疾病的关键。     

3例非典型异戊酸尿症患儿临床及基因型研究

目的探讨迟发型非典型异戊酸尿症患儿的临床、治疗及IVD基因突变特点。方法 3例非典型异戊酸尿症患儿,经尿液有机酸、血液酯酰肉碱谱分析发现异戊酸尿症,并经IVD基因突变检测确诊。患儿给予左卡尼汀、甘氨酸补充治疗及限亮氨酸饮食干预并进行随访。结果 3例患儿于1~2岁间发病,有不明原因呕吐、嗜睡,伴汗脚样体臭及代谢性酸中毒。3例患儿智力正常,均伴随显著的白细胞减少症,其中1例伴红细胞减少症。3例患儿血液异戊酰肉碱水平显著增高(4.6~8.2μmol/L),尿液异戊酰甘氨酸水平显著增高(36.1~1 783.56 mmol/mmol肌酐)。3例患儿IVD基因共检出6种突变,其中已知突变4种(c.157CT,c.214 GA,c.1183CG,c.1208AG),新突变2种(c.1039GA,c.1076AG)。经治疗后患儿顺利康复,目前1岁7个月~14岁,智力、运动及体格发育正常。结论迟发性异戊酸尿症临床表现复杂,于婴幼儿期发病,可有反复呕吐、酸中毒,通过血液酰基肉碱谱、尿液有机酸分析及基因分析确诊,左卡尼汀及饮食干预,疗效显著。     

海南省少数民族地区脂肪酸氧化代谢病新生儿筛查结果分析

目的 探讨海南省少数民族地区新生儿人群脂肪酸氧化代谢障碍（FAOD）的发病率,分析确诊患儿的临床特点,为海南省出生缺陷预防提供依据。方法 收集海南省少数民族地区2016年10月至2021年12月新生儿遗传代谢疾病串联质谱筛查数据。采用串联质谱技术检测新生儿干血斑中游离肉碱以及30种酰基肉碱水平。初筛阳性新生儿进行召回复查血串联质谱,气相质谱测尿有机酸,采集新生儿及其父母外周血进行基因测序。结果 研究期间共出生66 578名新生儿,参与筛查46 285名（69.5%）,初筛阳性513例（初筛阳性率为1/90）,召回501例,确诊FAOD 11例,发病率1/4208,其中原发性肉碱缺乏症6例,短链、中链、极长酰基辅酶A脱氢酶缺乏症各1例,肉碱棕榈酰转移酶Ⅰ和Ⅱ缺乏症各1例。结论 海南省少数民族地区新生儿人群FAOD发病率较高,以原发性肉碱缺乏症较为多见。建议将新生儿遗传代谢病串联质谱筛查纳入新生儿常规筛查项目。     

乙基丙二酸脑病患儿的临床研究及ETHE1基因新突变1例报告

目的 1例经EHTE1基因分析确诊的罕见的常染色体隐性遗传病——乙基丙二酸脑病。方法回顾性分析1例确诊乙基丙二酸脑病患儿的临床经过、基因突变特点等。结果女性患儿,7个月起出现顽固性腹泻,并逐渐出现智力运动发育落后及倒退,23个月时检测患儿血液丁酰肉碱4.48 mmol/L,异戊酰肉碱0.7 mmol/L;尿乙基丙二酸及甲基琥珀酸浓度显著增高;颅脑MRI显示双侧基底节区对称性异常信号,符合乙基丙二酸脑病;ETHE1基因分析发现2个杂合突变,其中c.488GA(p.R163Q)为已知突变,c.203TC(p.L68P)为未报道的新突变。患儿经免乳糖饮食,以及左卡尼汀、辅酶Q10、维生素B1、维生素B2、维生素C支持治疗后,全身情况改善,智力运动发育有所进步,但仍明显落后。结论尿液乙基丙二酸增高可见于线粒体脂肪酸代谢障碍等多种疾病,血液丁酰肉碱、异戊酰肉碱浓度增高是乙基丙二酸脑病的常见生化表现之一,ETHE1基因分析有助于确诊。     

肉碱棕榈酰转移酶Ⅱ缺乏症家系CPT2基因突变分析及产前诊断

分析肉碱棕榈酰转移酶Ⅱ（CPTⅡ）缺乏症患儿及其父母CPT2基因突变类型,为家系成员提供遗传咨询及产前诊断。先证者,女,于3个月时发烧8 h入院,血液酯酰肉碱谱分析显示棕榈酰肉碱显著增高,提示CPTⅡ缺乏症。收集患儿临床资料,采集患儿和父母外周血,提取基因组DNA,应用直接测序法进行CPT2基因5个外显子编码区及与外显子交界的部分内含子区域进行测序。患儿母亲于妊娠中期采取羊水,分取羊水细胞进行CPT2基因突变分析。Sanger测序发现先证者CPT2基因存在两个已知致病突变c.886C > T（p.R296X）和c.1148T > A（p.F383Y）,突变来自父母双方。母亲第二胎羊水细胞CPT2基因存在c.886C > T（p.R296X）,为致病基因携带者。胎儿出生后血液酯酰肉碱谱正常,发育正常。通过家系CPT2基因分析,证实了先证者死因为CPTⅡ缺乏症,在突变明确的前提下,成功地进行了下一胎同胞的产前诊断,为该家庭提供帮助。     

急性脑病起病的晚发枫糖尿症

枫糖尿症（maple syrup urine disease,MSUD）是一种较常见的氨基酸代谢障碍性疾病。患者通常在新生儿期至婴幼儿期发病,学龄期以急性脑病起病的病例未见报道。本文报道1例MSUD患儿,8岁6个月首次发病,以感染后急性脑病症状为主要临床表现,于发病第2天时来院,一般化验发现代谢性酸中毒、血尿酸增高、脑脊液蛋白质降低,头颅磁共振扫描显示双侧小脑齿状核、脑干、双侧丘脑、壳核、尾状核及双侧大脑半球皮层呈现长T1,长T2信号,头颅弥散频谱（DWI）示以上部位呈明显高信号。血代谢检查示：血亮氨酸/异亮氨酸、缬氨酸显著高于正常范围;尿液代谢结果示：2-羟基异戊酸、2-羟基丁酸、2-酮异戊酸和2-酮异己酸亦显著增高,提示MSUD。同时游离肉碱明显降低,提示继发性肉碱缺乏、酮症。经控制氨基酸摄入,予大剂量维生素B1、葡萄糖、左旋肉碱静脉点滴,入院后第5天病情明显好转,第7天病情完全恢复,未遗留任何中枢神经系统后遗症。根据患儿治疗效果考虑为硫胺有效型。继续给予维生素B1口服,控制蛋白质饮食（每日1 g/kg）治疗1个半月后复查,血、尿代谢结果完全正常,复查头颅MRI结果明显改善。对以急性脑病起病的病例,要警惕遗传代谢性疾病的可能。如能及时诊断、正确治疗,可以有效地预防中枢神经系统后遗症的发生,改善预后。     

全羧化酶合成酶缺乏症导致的婴儿死亡1例报告北大核心CSCD

回顾性分析2020年5月包头市第四医院收治的1例确诊为全羧化酶合成酶缺乏症的死亡婴儿的临床和分子遗传学资料。患儿男,2月龄29 d,因“喉中痰鸣5 d,抽搐1 d,昏迷半天”入院。反应差,代谢性酸中毒难以纠正,经积极治疗2 d后病情仍进一步加重,自动出院,返家当日死亡。血氨基酸及及酰基肉碱分析示3-羟基异戊酰肉碱及丙酰肉碱增高。尿液有机酸分析示3-羟基丙酸、丙酰甘氨酸、甲基巴豆酰甘氨酸、甲基枸橼酸升高。采用全外显子组测序示HLCS存在c.1522C>T(p.R508W)/c.782delG(p.G260V)复合杂合突变,经Sanger家系验证突变来源于父母。HLCS缺乏症临床表现不典型,对于重症肺炎合并癫痫及难以纠正的代谢性酸中毒患儿,应考虑HLCS缺乏症可能,及时行代谢筛查及基因分析确诊。     

婴儿手足口病后肢体扭转伴发育倒退1月

患儿,女,1岁,因手足口病后肢体扭转、发育倒退1个月就诊。患儿11个月时因发热5d,皮疹伴频繁抽搐2d在当地就诊,诊断"手足口病重型、病毒性脑炎、癫癎持续状态"。颅脑MRI显示双侧基底节,双侧丘脑、大脑脚、双侧皮层及海马对称性异常信号。给予免疫球蛋白、抗病毒以及抗惊厥药物等治疗2周,效果不佳。为查明病因,进行了遗传代谢病血尿筛查。尿有机酸分析示戊二酸及3-羟基戊二酸显著增高,血戊二酰肉碱正常、游离肉碱降低。提示戊二酸尿症1型。经低赖氨酸饮食、左卡尼汀、巴氯芬等治疗1个月后患儿症状明显改善。手足口病是儿科常见病毒感染性疾病,患有遗传代谢病、免疫缺陷等潜在疾病的患儿可能出现严重合并症。对于手足口病合并难以解释的脑病患儿,应考虑潜在的遗传代谢性疾病。     

Phenotypic and mutation spectrums of Thai patients with isovaleric acidemia

Background: Isovaleric acidemia (IVA) is an autosomal recessive disorder caused by deficiency of isovaleryl‐CoA dehydrogenase (IVD). Clinical features include vomiting, lethargy, metabolic acidosis, and “sweaty feet” odor. The pathognomonic metabolite, isovalerylglycine, is detected on urine organic acid analysis. Clinical diagnosis of IVA can be confirmed on mutation analysis of the IVD gene. Methods: The cases of five unrelated Thai patients with IVA, identified on urine organic acid analysis, are described. Mutation analysis of the IVD gene was performed using polymerase chain reaction sequencing of the entire coding regions. Results: Four out of the five IVA patients had an acute neonatal form. The hematologic abnormalities were common and thus could be presenting symptoms in the absence of metabolic acidosis. As for the neurological outcome, only one patient had normal intelligence. Mutation analysis of the IVD gene identified the mutations c.457–3_2CA>GG, c.1199A>G (p.Y371C), c.281C>G (p.A65G), c.358G>A (p.G91R), and c.827T>C (p.L247P). The poor outcome in most patients might be explained by the delayed diagnosis and initial unavailability of the metabolic formulas and medications in Thailand. The c.457–3_2CA>GG mutation was identified in all of the present patients. This suggests that it is the most common mutation in the Thai population. Therefore, it could be a founder mutation in Thai subjects. One of the present Thai IVA patients also had the p.Y371C mutation, which is common in Han Chinese subjects. In addition, two novel mutations, p.A65G and p.L247P, were identified. Conclusion: The present study provides additional knowledge on the genotype–phenotype of IVA, suggesting that IVD mutations in Asian populations are distinct from these in Western populations.     

Holocarboxylase synthetase deficiency induced by HLCS gene mutations: a rare disease study北大核心CSCD

男性患儿,16月龄,因发现头面部红斑15个月,外阴红斑10个月,加重5 d就诊。患儿新生儿期即出现口周、眼周红斑,婴儿期出现颈部、腋下、外阴三角区等腔口和皱褶部位的红斑、丘疹,可见脱屑和糜烂。血气分析提示代谢性酸中毒,血遗传代谢病氨基酸和酰基肉碱谱分析、尿液有机酸分析结果均提示多种羧化酶缺乏症,基因检测结果提示HLCS基因存在c.1522C>T(p.R508W)纯合突变。最终该患儿诊断为全羧化酶合成酶缺乏症,口服生物素治疗取得良好的临床疗效。该文总结了1例全羧化酶合成酶缺乏症患儿的临床资料,对其病因、诊断、治疗进行归纳总结,为临床医生诊断该类罕见疾病提供思路。     

以脑积水起病的甲基丙二酸尿症合并同型半胱氨酸血症1例报道

甲基丙二酸尿症合并同型半胱氨酸血症极少以脑积水起病。本文报道1例以脑积水起病的该病病例,并进行文献复习,探讨该类有机酸代谢病与脑积水的关系。该患儿以抽搐、脑积水起病,存在大细胞性贫血,发育评估落后,视听功能损伤,脑电图高峰失律,头颅磁共振及超声证实脑积水。血同型半胱氨酸升高,为143.06μmol/L,尿代谢筛查甲基丙二酸浓度为正常值的1483倍,基因检测确诊甲基丙二酸尿症合并同型半胱氨酸血症,为位于1p34.1的c.609G>A纯合突变,属于CblC型维生素B12合成酶缺陷。确诊后加用静脉维生素B12、口服叶酸、甜菜碱后,患儿抽搐缓解,脑室回缩,发育较前进步。因此,对于没有明确病因以脑积水作为主诉就诊的患儿,应注意排查代谢性疾病。     

Screening newborns for multiple organic acidurias in dried filter paper urine samples: method development

Screening urine for inherited and acquired organic acidurias in newborns has the potential of preventing severe disease, mental retardation, and death. A method for screening dried urine filter paper samples for acidic markers of at least 20 different metabolic conditions has been developed. These conditions include, among others, maple syrup urine disease; methylmalonic, propionic, isovaleric, glutaric, and hydroxymethylglutaric acidurias; methylcrotonylglycinuria; medium-chain acyl-CoA dehydrogenase deficiency; inherited vitamin responsive disorders B12, biotin, B2), and acquired deficiencies of these vitamins. The preparation of the urine extract is identical to the method we use to screen infants for neuroblastoma. Screening is based on a highly sensitive and specific determination of eight organic acid markers by an automated computerized gas chromatography mass spectrometry system using selected ion monitoring. The markers used for screening are methylmalonic acid, 2-hydroxyisocaproic acid, glutaric acid, propionylglycine, isovalerylglycine, 3-methylcrotonylglycine, hexanoylglycine, and 3-phenylpropionylglycine. The extraction efficiencies of these acids from dried filter paper were similar to extraction from water, ranging from about 40% to 80%, except for propionylglycine which showed a low extraction efficiency of 11-13%. The stability of these acids on filter paper exposed to room air and temperature over a period of 15 d was adequate for the use of this collection method for organic aciduria screening. Normal levels, adjusted to urinary creatinine, were established for these acids in 519 urine filter paper samples obtained from 3-wk-old newborns. This screening method was tested on samples obtained from 12 patients with known organic acidurias including stored urine filter paper collected at 3-wk of age from two infants later found to have organic acidurias.     

罕见病研究：CTNS基因突变致胱氨酸贮积症

1岁6月龄男性患儿,4月龄时发现持续尿糖阳性,伴多饮、多尿、生长迟缓,辅助检查提示患儿存在低比重尿、贫血、低钾血症、低钠血症、低镁血症、代谢性酸中毒、糖尿、氨基酸尿、钾排泄分数增高、肾小管磷重吸收率降低,头颅、胸部及右手腕X线提示肾性佝偻病改变,裂隙灯检查观察到角膜出现大量结晶,基因检查示CTNS基因存在可疑致病性纯合突变c.922G>A(p.Gly308Arg),该患儿最终诊断为胱氨酸贮积症。治疗初期予对症支持治疗,维持内环境稳定,确诊后特异性应用半胱胺酒石酸胶囊行清除胱氨酸治疗。该文报道了1例CTNS基因突变致胱氨酸贮积症患儿,对该病病因、临床特征、诊疗等进行归纳总结,为该病的早期诊断、治疗及后续研究提供参考依据。     

An unusual late-onset case of propionic acidaemia: biochemical investigations, neuroradiological findings and mutation analysis

We report a 5-year-old boy with propionic acidaemia who developed a rapidly fatal necrosis of the basal ganglia after an episode of clinical deterioration. Neither metabolic acidosis nor hyperammonaemia were present. Organic acid analysis in both urine and CSF showed increased levels of methylcitric and 3-hydroxypropionic acids. Propionic acidaemia was confirmed by demonstrating a propionyl-CoA carboxylase deficiency (11% of control value) in skin fibroblasts. DNA analysis revealed that the patient was a compound heterozygote for two mutations in the PCCB gene. Conclusion Propionic acidaemia can present as a sudden and fatal neurological disease and not only as an organic aciduria with severe biochemical dis-turbances and progressive neurological deterioration. Received: 24 March 1997 / Accepted in revised form: 14 July 1997     

Acetaminophen-induced hepatotoxicity in a glutathione synthetase-deficient patient

We report a patient with glutathione synthetase (GS) deficiency who developed acetaminophen-induced hepatotoxicity after a two-day treatment with regular doses of acetaminophen. A nine-month-old female was referred because of intractable metabolic acidosis. She was given acetaminophen at therapeutic doses over a 48-hour period. She was hospitalized because of confusion and metabolic acidosis. Liver function tests were abnormal with normal bilirubin levels. The urine gas chromatography-mass spectrometry (GC/MS) showed massive excretion of 5-oxoproline. She improved and liver function tests normalized in the next six days, but compensated metabolic acidosis and massive 5-oxoprolinuria persisted. The analysis of GS in erythrocytes revealed 5% of normal enzyme activity, and the patient had 491G > A mutation on both alleles in the GS gene. In this report it can be assumed that patients, even if heterozygous for a mutation of the GS gene, are at risk for acetaminophen toxicity.