一例3-羟基-3-甲基戊二酸尿症患儿的临床特点及基因分析

目的:探讨3-羟基-3-甲基戊二酰辅酶A裂解酶缺乏症(3-hydroxy-3-methylglutaryl-CoA lyase deficiency,HLD)患儿的临床特征和基因变异。方法:收集1例中山大学附属第六医院儿科2019年4月确诊的1例HLD患儿的临床表现、实验室检查及基因检测等临床资料,并以"3-羟基-3-...     

3-羟基-3甲基戊二酰辅酶A裂解酶缺乏症临床特点及基因变异分析

目的 了解3-羟基-3甲基戊二酰辅酶A裂解酶缺乏症的临床特点及基因变异情况。方法 分析6例3-羟基-3甲基戊二酰辅酶A裂解酶缺乏症患儿的临床资料及基因检测结果。结果 6例患儿,男性3例,女性3例。1例家族史阳性。3例患儿当地医院行新生儿筛查提示该疾病,2例患儿为发病后临床诊断,1例患儿至今未发病。5例患儿发病年龄10天～5岁。初诊年龄为1个月～7岁,发病时均有不同程度的代谢危象、低血糖和高乳酸血症等表现。2例患儿死亡。血串联质谱显示3-羟基异戊酰肉碱升高,部分患儿伴有己二酰肉碱升高;尿有机酸分析提示3-羟基-3-甲基戊二酸显著升高,伴3-甲基戊烯二酸、3-羟基异戊酸等增高。4例患儿基因检测均发现HMGCL基因变异：2例c.122G>A(p.R41Q)纯合;1例c.697C>T(p.H233Y)纯合;1例c.145-2A>G和c.590G>A(p.C197Y)复合杂合。其中,c.697C>T(p.H 233Y)、c.145-2A>G和c.590G>A(p.C197Y)变异均为首次报道,蛋白结构预测均为可能有害,ACMG评级为可能致病。另2例患儿未...     

气相色谱-质谱联用技术在3-羟基-3-甲基戊二酸尿症诊断中的应用

目的 建立尿素酶预处理气相色谱-质谱联用技术(GC-MS)定量检测3-羟基-3-甲基戊二酸的方法,用于临床鉴别诊断3-羟基-3-甲基戊二酸尿症(3-HMG).方法 尿3-羟基-3-甲基戊二酸经尿素酶预处理,残余物进行三甲基硅烷化(BSTFA-TMCS)衍生,衍生化后进行GC-MS测定分析,采用总离子扫描模式进行检测.3-羟基-3-甲基戊二酸存在2种衍生化形式,即2个硅烷化(di-TMS)和3个硅烷化(tri-TMS)形式,分别选择特征离子m/z 175(di-TMS)和363(tri-TMS)为定量离子,内标十七烷酸选择特征离子m/z 327为定量离子.分析该法精密度、稳定性、样本回收率.用该法检测10例代谢性酸中毒、低血糖、未伴酮症、高度怀疑3-HMG的患儿尿样.结果 3-羟基-3-甲基戊二酸定量范围为6.17 ～1 234.56μmol·L-,线性方程为Y =0.284 3X-0.003,线性相关系数为0.998 6,低、中、高水平批内变异系数为2.17％、7.79％、5.78％;批间变异系数为4.19％、4.73％、9.24％;回收率为88.25％～108.47％.诊断3-HMG 1例,尿3-羟基-3-甲基戊二酸水平为219.86 mmol·mol-1肌酐.结论 尿素酶预处理GC-MS测定尿3-羟基-3-甲基戊二酸具有较高的回收率、精密度和准确性,可为临床诊断3-HMG提供参考依据.     

儿童抗3-羟基-3-甲基戊二酰-辅酶A还原酶抗体肌病临床特点和治疗分析

目的:探讨儿童抗3-羟基-3-甲基戊二酰-辅酶A还原酶(HMGCR)抗体肌病的临床特点和治疗。方法:回顾性分析2020年1月至7月深圳市儿童医院神经内科收治的2例儿童抗HMGCR抗体肌病的临床表现、血清肌酸激酶(CK)、肌炎抗体、肌电图、肌肉病理、磁共振成像(MRI)、治疗等资料。结果:2例均为女性患儿,例1为3岁11...     

戊二酸尿症1型的复杂临床表型与基因型

戊二酸尿症1型为罕见的有机酸尿症,为常染色体隐性遗传病。戊二酰辅酶A脱氢酶(GCDH)基因缺陷导致戊二酰辅酶A脱氢酶活性降低或缺陷,导致戊二酸、3-羟基戊二酸在体内蓄积,引起纹状体等神经核团损害,导致神经退行性疾病。患者临床表型及基因型复杂,个体差异显著,胎儿期至成年均可发病,轻症患者发病前几乎无临床症状,重者表现为严重的急性代谢性脑病,导致死亡或残障。婴幼儿时期常因发热、外伤、饥饿、高蛋白饮食、疫苗接种等诱因引发急性脑病。患者发病年龄越早症状越重,预后越差。尿有机酸、血液酯酰肉碱谱分析及GCDH基因检测是诊断戊二酸尿症1型的重要方法,新生儿筛查是早期诊断、改善预后的关键。     

戊二酸尿症Ⅰ型1例临床和基因突变分析

目的探讨戊二酸尿症Ⅰ型的基因突变特点。方法回顾分析1例戊二酸尿症Ⅰ型患儿的临床资料及基因检测结果。结果女性患儿,1岁11个月,主要表现为腹泻及抽搐。血戊二酰肉碱水平(0.78μmol/L)及尿戊二酸显著增高。二代测序发现GCDH基因两处变异,c.271+1GA(IVS4+1GA),为父源性剪切变异;c.938GA为母源性错义变异。两处变异的致病性均已有文献报道,但均是国内首次报道。结论扩充了国内戊二酸尿症Ⅰ型的基因突变谱。     

线粒体3-羟基3-甲基戊二酰辅酶A合成酶缺乏症1例并文献复习

线粒体3-羟基3-甲基戊二酰辅酶A合成酶缺乏症（HMCSD）是由于HMGCS2基因变异导致的罕见酮体生成障碍疾病。该研究报道1例该病。患者,女,8个月,因腹泻1周,发热、抽搐1天入院,病程中出现抽搐以及酸中毒、低血糖、肝功能损害、心肌损伤、凝血功能异常等表现。基因检测发现患者HMGCS2基因存在新发c.1502G > A（p.R501Q）纯合突变,生物信息学软件分析提示有害;尿有机酸分析提示4-羟基-6-甲基-2-吡喃酮明显增高,与基因检测结果吻合。患者最后确诊为HMCSD。     

线粒体3-羟基-3-甲基戊二酰辅酶A合成酶缺乏症1例分析及文献回顾

目的探讨线粒体3-羟基-3甲基戊二酰辅酶A合成酶缺乏症(HMCSD)的临床及遗传学特征。方法回顾分析1例HMCSD患儿的临床资料,并复习相关文献。结果女性患儿,9个月余,先后因呕吐、抽搐及发热、咳嗽就诊。血生化检查示低血糖、代谢性酸中毒、肝功能异常、凝血功能异常,尿筛查示双羧酸尿。基因检测发现HMGCS2基因存在6号外显子c.1187+1GC和3号外显子c.648GT复合杂合突变,确诊为HMCSD。此突变未见报道。患儿经积极抗感染、纠正代谢性酸中毒、维持血糖稳定及补充左卡尼汀等治疗后好转。随访半年智力运动发育正常。结论 HMCSD临床表现多样,基因检测可明确诊断,早期识别、早期诊治有助于改善预后。     

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。     

3-羟基异丁酰辅酶A水解酶缺乏症一例诊治体会并文献复习

报道一例3-羟基异丁酰辅酶A水解酶缺乏症,并结合文献,探讨其临床特征、基因突变特点和诊疗现状。患儿,男,1岁6个月,发热、腹泻后出现发育倒退、阵发性肌张力不全等症状;头部MRI提示双侧基底节对称性病变。线粒体基因组全长检测未发现致病突变。线粒体相关疾病核基因检测发现患儿HIBCH基因新发复合杂合突变：c.439-2A > G和c.958A > G （p.K320E）,分别遗传自其父母。予以患儿"鸡尾酒疗法"、限制缬氨酸饮食及对症治疗,2周后患儿肌张力不全症状改善,运动以及智能较前缓慢进步。     

3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency: review of 18 reported patients

3-Hydroxy-3-methylglutaryl-coenzyme A lyase deficiency (HMG-CoA lyase) is an inborn error of leucine catabolism which often leads to life-threatening illness in the neonatal period. The cardinal clinical features include severe infantile hypoglycemia, metabolic acidosis, hepatomegaly, lethargy or coma and apnea. Hyperammonemia is variable. There is a characteristic absence of ketosis. Considerable heterogeneity has been observed in clinical and biochemical presentation. Acute episodes of illness have been mistaken for Reye syndrome. The pattern of organic acids in the urine includes large amounts of 3-hydroxy-3-methylglutaric, 3-methylglutaconic, 3-methylglutaric and 3-hydroxyisovaleric acids. Smaller, but appreciable levels of glutaric, adipic and other dicarboxylic acids may also be excreted in the urine. Lactic acid may be present in sizable amounts at times of acute illness. The primary defect is a deficiency of 3-hydroxy-3-methylglutaryl-coenzyme A lyase, a key enzyme in the cycle of ketogenesis.Abbreviation HMG-CoA lyase 3-hydroxy-3-methylglutaryl-coenzyme A lyase     

The contribution of protein catabolism to metabolic decompensation in 3-hydroxy-3-methylglutaric aciduria

Leucine and protein metabolism were studied using stable isotope techniques in 6-year-old twins with 3-hydroxy-3-methylglutaric aciduria during acute metabolic decompensation. The decompensation was preceded by prolonged fasting in twin 1 and by an upper respiratory infection in twin 2. Twin 2 was also studied when well (control study). During infection, leucine oxidation (36 mol/kg per hour), protein catabolism (6.0 g/kg per day) and urinary excretion of major leucine metabolites (104 mol/kg per hour) were all increased compared with the control study (16 mol/kg per hour, 4.7 g/kg per day and 28 mol/kg per hour respectively). During fasting, leucine oxidation (18 mol/kg per hour) was unchanged and protein catabolism (4.1 g/kg per day) was decreased despite substantially increased urinary metabolite excretion (87 mol/kg per hour) compared with the control study. These results indicate that protein mobilisation and leucine oxidation played important roles in metabolic decompensation during infection but not during fasting. It is likely that the increased metabolite excretion during fasting arose primarily from fatty acid catabolism, indicating the importance of this substrate in metabolic decompensation in 3-hydroxy-3-methylglutaric aciduria.     

Dizygotic twins with 3-hydroxy-3-methylglutaric aciduria; unusual presentation,family studies and dietary management

A 4-month-old infant with hypotonia and macrocephaly was diagnosed as having 3-hydroxy-3-methylglutaric aciduria, using gas chromatography and mass spectrometry and confirmatory enzyme studies. The same diagnosis was made on his asymptomatic non-indentical twin. Examination of the pedigree is consistent with an autosomal recessive mode of inheritance. Dietary treatment improved the symptoms of the propositus, but did not prevent episodes similar to Reye's syndrome in both twins. One such episode closely followed immunisation and our experience suggests that children with this disorder should be observed carefully following immunisation. These episodes were accompanied by an overflow of a wide range of abnormal metabolites.Examination of the urine for organic acids should be considered in infants with unexplained hypotonia and macrocephaly, especially if accompanied by abnormal biochemical indices.     

3-Methylglutaconic and 3-methylglutaric aciduria in a patient with suspected 3-methylglutaconyl-CoA hydratase deficiency

A girl suffering from marked muscular hypotonia, severe statomotor and mental retardation, bilateral optic atrophy with chorioretinal degeneration, convulsions and a moderate compensated metabolic acidosis is described. Screening for metabolic disorders revealed massive 3-methylglutaconic with 3-methylglutaric aciduria leading to the tentative diagnosis of 3-methylglutaconyl-CoA hydratase deficiency. Metabolite excretion was correlated with variation of leucine intake. 3-methyl-3-hydroxyglutaryl-CoA lyase activity in cultured fibroblasts was normal. The suspected metabolic defect was not demonstrable in cultured skin fibroblasts, however.Abbreviation MSUD Maple syrup urine disease     

Stroke-like encephalopathy in an infant with 3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency

A 2.5-year-old boy presented with acute metabolic decompensation in whom 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) lyase deficiency was diagnosed. Four days after metabolic decompensation, a stroke-like encephalopathy with tonic clonic convulsion of the left arm and leg and coma developed. Brain oedema and subsequent demarcation and atrophy were observed mainly within the supply areas of the right anterior and middle cerebral artery and to a lesser extent in various sites within the right hemisphere. Residual neurological deficits included spastic paresis of the left arm and leg, and left supranuclear facial palsy and aphasia, indicating bilateral diffuse brain affection. Conclusion In the presented patient with HMG-CoA lyase deficiency, stroke-like encephalopathy occurred days after metabolic decompensation indicating ongoing (intracerebral) metabolic derangement. Monitoring of the intracerebral accumulation of toxic metabolites by magnetic resonance spectroscopy and of cerebral haemodynamics might be useful for a better understanding of the pathogenetic mechanisms of stroke-like encephalopathy and to identify patients at risk. Received: 31 August 1997 and in revised form 30 January 1998 / Accepted: 31 January 1998     

3-Methylglutaconic aciduria: a phenotype in which activity of 3-methylglutaconyl-coenzyme A hydratase is normal

3-Methylglutaconic aciduria has been found in two distinct syndromes. In one there is deficient activity of 3-methylglutaconyl coenzyme A hydratase, and the only clinical manifestation observed has been retardation of speech development. In the other, which includes a majority of the patients studied, we document that the activity of this enzyme in fibroblast extracts is normal. The phenotype of this disorder is one of profound neurological impairment with retarded psychomotor development, hypotonicity and/or spasticity, convulsions or EEG abnormalities, and sensorineural changes in the eye and ear.Abbreviations 3-MG-CoA 3-methylglutaconyl coenzyme A - PAS periodic acid-Schiff - ATP adenosine-5-triphosphate - HMG 3-hydroxy-3-methylglutaric acid - 3-HB 3-hydroxybutyric acid - EDTA ethylene-diaminetetra-acetic acid     

Detection of late onset steroid 21-hydroxylase deficiency by capillary gas chromatographic profiling of urinary steroids in children and adolescents

Patients suffering from late onset 21-hydroxylase deficiency (LO-CAH) excreted only slightly higher amounts of 17-hydroxypregnanolone (17-OH-PO), pregnanetriol (PT) and 11-oxo-pregnanetriol (11-O-PT) than age-matched healthy controls. To discriminate between LO-CAH and virilization of unknown origin and precocious pubarche, we calculated the following ratios: (1) pregnanetriol to tetrahydrocortisone (PT/THE), (2) the sum of 17-OH-PO, PT and 11-O-PT (OHP-M) to the sum of THE, tetrahydrocortisol (THF) and allotetrahydrocortisol (a-THF) (C-M) and (3) 11-O-PT to C-M. The following patients were studied: 9 patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency-non-salt losing (CAH-NSL), never treated; 8 patients with CAH (NSL/SL: 3/5) off treatment; 10 patients with LO-CAH; 11 patients with virilization of unknown origin (prepubertal/pubertal: 5/6) and 9 patients with precocious pubarche. Healthy individuals and obligatory heterozygote carriers of comparable ages served as controls. LO-CAH showed increased ratios (median (range)) of PT/THE: 2.27, (1.15–9.09), OHP-M/C-M: 2.30, (1.24–8.15), and 11-O-PT/C-M: 0.24, (0.13–1.23) compared to healthy individuals and heterozygous carriers: PT/THE 0.28, (0.03–0.57), OHP-M/C-M 0.23, (0.06–0.46) and 11-O-PT/C-M<0.01, (<0.01–0.06), respectively. The calculation of ratios, rather than absolute amounts seems to allow the detection of LO-CAH in a single spontaneously voided urine specimen. The clinical and measurable hormonal manifestations of LO-CAH occur at the same time.Abbreviations LO-CAH late onset 21-hydroxylase deficiency - CAH congenital adrenal hyperplasia due to 21-hydroxylase deficiency - SL salt losing - NSL non-salt losing - p.p. prepubertal - p. pubertal - 17-OH-PO 17-hydroxypregnanolone (5-pregnane-3,17-diol-20-one) - PT pregnanetriol (5-pregnane-3,17,20-triol) - 11-O-PT 11-oxo-pregnanetriol (5-pregnane-3,17,20-triol-11-one) - THE tetrahydrocortisone (5-pregnane-3,17,21-triol-11,20-dione) - THF tetrahydrocortisol (5-pregnane-3,11,17,21-tetrol-20-one) - a-THF allotetrahydrocortisol (5-pregnane-3,11,17,21-tetrol-20-one) - OHP-M 17-OH-PO+PT+11-O-PT - C-M THE+THF+a-THF Dedicated to Prof. Enno Kleihauer, Ulm, on the occasion of his 60th birthday     

Relapsing encephalopathy with cerebellar ataxia are caused by variants involving p.Arg756 in ATP1A3

Mutations in ATP1A3 lead to different phenotypes having in common acute neurological decompensation episodes triggered by a specific circumstance and followed by sequelae. Alongside Alternating Hemiplegia of Childhood (AHC), Rapid-onset Dystonia Parkinsonism (RDP) and Cerebellar ataxia, Areflexia, Pes cavus, Optic atrophy, Sensorineural hearing loss syndrome (CAPOS), a new Relapsing Encephalopathy with Cerebellar Ataxia (RECA) phenotype was published in 2015. We describe herein eight new pediatric cases. Most of them had no specific history when the first neurological decompensation episode occurred, before the age of 5 years, triggered by fever with severe paralytic hypotonia followed by ataxia with or without abnormal movements. Neurological sequelae with ataxia as the predominant symptom were present after the first episode in three cases and after at least one subsequent relapse in five cases. Five of the eight cases had a familial involvement with one of the two parents affected. The phenotype–genotype correlation is unequivocal with the causal substitution always located at position 756. The pathophysiology of the dysfunctions of the mutated ATPase pump, triggered by fever is unknown. Severe recurrent neurological decompensation episodes triggered by fever, without any metabolic cause, should lead to the sequencing of ATP1A3.