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。     

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-...     

新生儿异戊酸血症一例

患儿女,生后8d,因鼻塞伴奶量减少1d入院。患儿系第6胎第2产,胎龄41周,顺产,出生体重3000g,无窒息史,母乳喂养,吸吮有力。否认家族遗传病史。母亲曾人工流产4次,患儿胞兄生后7d因抽搐、昏迷在当地医院死亡,当时诊断VitK缺乏颅内出血。患儿无发热,无咳嗽、气促,无呕吐、腹泻,无尖叫、抽搐等。入院查体:生命体征平稳,反应可,全身轻度汗脚臭味,原始反射存在,四肢肌张力正常。入院诊断:上呼吸道感染。入院予以抗感染、对症治疗,静脉输注6%小儿氨基酸30ml+5%葡萄糖。治疗5h,患儿突然出现双上肢抽动,持续3min自行缓解,但反复发作,神志由淡漠到浅昏迷,无大汗、发热等。查体:P136次/mi     

新生儿全血细胞减少伴代谢异常

患儿,男,9d,急性起病,表现为咳嗽、气促、喂养困难、嗜睡、昏迷。辅助检查提示肺部感染、严重代谢性酸中毒、高血糖、高血氨、血象三系减少。为查明病因,进行了血液酯酰肉碱谱及尿液有机酸分析及基因诊断。结果发现：血异戊酰肉碱及尿异戊酰甘氨酸和3-羟基异戊酸显著升高,游离肉碱降低,提示异戊酸血症 （IVA）;基因检测提示第12号外显子纯合突变c.1208A > G （p.Tyr403Cys）,父母为杂合突变携带者。经低亮氨酸饮食、左卡尼汀等治疗后症状稍改善,但1周后患儿死亡。新生儿肺炎是新生儿常见感染,但可能是遗传代谢病患儿的诱发因素,因此对于肺炎起病的伴有难以解释的代谢异常患儿,应进行遗传代谢性疾病筛查。     

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.     

单纯型甲基丙二酸尿症126例的临床表型与基因型研究北大核心CSCD

目的：探讨单纯型甲基丙二酸尿症患者的临床、生化及基因特点。方法选取2001年1月至2014年12月北京大学第一医院诊断的126例单纯型甲基丙二酸尿症患者,男81例,女45例。其中60例行基因分析。对患儿的临床经过、生化特点、影像学异常、基因型及预后等进行研究。结果126例患儿中仅3例（2.4％）为新生儿筛查发现,于1个月左右开始饮食与维生素 B12、左卡尼汀支持治疗,无症状;123例（97.6％）患儿为临床高危筛查发现,于出生后数小时~7岁11个月发病,主要表现为反复呕吐、喂养困难、发育落后、嗜睡、呼吸困难、昏迷、抽搐、皮肤损害、黄疸等。27例（21.4％）有异常家族史,有同胞不明原因死亡或残障。一般辅助检查常见异常为代谢性酸中毒、贫血。头颅 MRI 异常以双侧基底核对称性损害及白质改变为主。60例接受基因分析的患者中,MUT 缺陷58例,MMAA 缺陷、MMAB 缺陷各1例。MUT 基因缺陷中共检出46种突变,其中12种为新突变。112例患儿经治疗后临床症状改善,但仍遗留不同程度的智力运动障碍及多脏器损伤。11例（8.73％）患儿死亡。仅3例智力运动发育正常。结论单纯型甲基丙二酸尿症患者临床表现复杂,易出现代谢危象,MUT 基因缺陷是主要病因,早期诊断、合理治疗至关重要。新生儿筛查是早期发现甲基丙二酸尿症的关键。     

2甲基3羟基丁酰辅酶A脱氢酶缺陷症一家系基因突变分析

目的 对一个2甲基3羟基丁酰辅酶A脱氢酶缺陷症(MHBDD)家系进行基因突变分析,为疾病的诊断及遗传咨询提供依据.方法 采集患儿及父母外周静脉血,分别提取总RNA及基因组DNA.应用RT-PCR方法扩增ACAT1基因全编码区序列.应用PCR方法扩增ACAT1基因启动子序列及HADH2基因全部外显子编码区及两侧内含子区域.所有扩增产物,均进行直接测序并与参考序列进行比对.结果 患儿1岁1个月,主要表现为精神运动发育迟缓,就诊时尚不能独站,生化检测血乳酸升高(3.19 mmol/L),头颅核磁提示髓鞘发育延迟,气相色谱质谱检测提示乙酰乙酰辅酶A硫解酶缺陷症.ACAT1基因全编码区及启动子区域未见异常突变位点,HADH2基因第4外显子发生c.388C ＞T(p.R130C)半合子改变,使编码的第130位精氨酸变成了半胱氨酸.患者母亲该位点为杂合改变,父亲正常.结论 通过基因突变分析确诊了1例2甲基3羟基丁酰辅酶A脱氢酶缺陷症患儿,p.R130C是该患儿的致病突变,为准确的遗传咨询提供了可能.     

有机酸血（尿）症及其临床处理

有机酸血（尿）症是临床最常见的一类遗传代谢病,目前已经发现约50余种,多数在新生儿期或婴幼儿期发病.临床上多表现为顽固性代谢性酸中毒、发作性呕吐、喂养困难、肌张力低下、惊厥和意识障碍等.由于本类疾病临床没有特异性,若不能早期诊断和治疗,易出现猝死或不可逆转的神经系统损伤.利用气相色谱-质谱联用技术和（或）串联质谱技术对疑似有机酸血（尿）症患儿进行早期生化诊断是改善患儿预后和挽救患儿生命的关键.     

精氨酰琥珀酸尿症导致新生儿死亡1例报告

目的报道1例早发型精氨酰琥珀酸尿症病例。方法女性患儿,于出生第2天发病,入院后经临床及实验室检查、基因检测获得诊断。结果患儿血氨显著增高,肝功能异常,伴代谢性酸中毒,血钾、血钙降低。血液瓜氨酸显著增高(1 098.12μmol/L)、精氨酸降低,尿乳清酸、尿嘧啶、精氨酰琥珀酸显著增高。经精氨酸支持、低蛋白饮食治疗无效,病情进行性加重,于生后23 d死亡。基因分析证实精氨酰琥珀酸裂解酶ASL基因存在c.544CT(p.R182X)和c.706CT(p.R236W)复合杂合突变,父母各携带1个杂合突变。结论此例为国内首次报道的早发型精氨酰琥珀酸尿症,死亡后获得确诊。精氨酰琥珀酸尿症是严重的遗传代谢疾病,临床诊断困难,生化特点为血瓜氨酸及尿精氨酰琥珀酸显著增高,ASL基因检测是诊断的关键。     

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.     

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??Objective To analyze the clinical features?? mutation types?? treatment and outcomes of methylmalonic acidemia combined with homocysteinemia??MMA-HC?? in children??in order to improve the clinical understanding of this disease.
Methods The clinical data??mutation types??treatment and outcomes of 11 children with MMA-HC were retrospectively analyzed to find the relationships of clinical phenotypes and genotypes with the prognosis of the early-onset??≤1 year?? and late-onset ????1 year?? patients. Results In the 9 early-onset children with more serious clinical manifestations??the major gene mutation type was c.609G??A and C.658_660delAAG??the mutation types of 2 cases of late-onset children were c.482G??A/c.609 G??A and c.394C??T/c.80A??G compound heterozygous mutations. The children with C.609G??A/c.658_660delAAG compound heterozygous mutation in early-onset patients had poorer clinical manifestations and prognosis. In contrast??the other early-onset children were relatively good. After treatment??the prognosis of late-onset children were usually good. Conclusion Combined-type MMA children have various clinical manifestations and individual differences. Seizures??lethargy??feeding difficulty and no increase of weight are the common symptoms in early-onset children??while in late-onset patients there is occult onset??chronic mental disorders??mental retardation and weakness of two legs. Early treatment with hydroxycobalamin can significantly improve the clinical symptoms in the children??but the prognosis still depends on the clinical phenotype and genotype.     

Barth综合征3例临床表现及基因突变分析

目的探讨Barth综合征(BTHS)的临床表现、诊断、治疗及转归。方法回顾性分析2013年6月至2014年10月经基因检测确诊的3例BTHS患儿的临床资料。结果 3例患儿均为男性,其中2例为双胞胎。3例患儿均以心肌病和心功能不全为主要表现,同时合并不同程度的左室心肌疏松,其中2例诊断为左室心肌致密化不全(LVNC);3例患儿均有运动发育迟缓和肌无力表现,生长发育落后;尿液3-甲基戊烯二酸(3-MGCA)水平显著增高,其中1例合并中性粒细胞减少;3例患儿均检测到TAZ基因突变,2例双胞胎患儿检测到1个新的错义突变c.527AG(p.H176R),另外1例患儿检测到1个已知的无义突变c.367CT(p.R123X),突变均来源于患儿母亲。随访过程中2例双胞胎分别于生后7个月和7个半月死亡,另1例目前存活。结论 BTHS是引起儿童心肌病的原因之一,对于合并有肌无力、中性粒细胞减少、3-甲基戊烯二酸尿症等表现的男性心肌病患儿,尤其是合并LVNC时,需要重视BTHS的筛查。     

A study of urinary metabolites in patients with dicarboxylic aciduria for differential diagnosis

Dicarboxylic aciduria (DCA-uria) is a relatively common finding in the screening of organic acidemias by gas chromatography/mass spectrometry (GC/MS). A considerable number of patients with DCA-uria are involved in disturbances of mitochondrial and peroxisomal fatty acid β-oxidation. The differential diagnosis of DCA-uria was investigated using a combination of organic acid analysis by GC/MS, carnitine determination, acylcarnitines by fast atom bombardment/mass spectrometry (FAB/MS) and acylglycines by stable-isotope dilution analysis. The relative distribution of urinary metabolites was examined in 46 patients with DCA-uria of different origins, including physiological ketosis of childhood, disorders of propionic acid metabolism, glutaric aciduria type II, Zellweger syndrome and patients who were clinically diagnosed as having Reye syndrome. Zellweger syndrome seemed to be distinguishable from other disorders by the high sebacic acid/adipic acid ratio of DCA-uria and increased excretion of 4-hydroxyphenyllactic acid and 2-hydroxysebacic acid. The mild form of glutaric aciduria type II was often missed by current organic acid analysis alone, but was readily diagnosed by acylcarnitine and acylglycine determination. The ratio of free/total carnitine was low in most of the DCA-uria patients except for two of five cases of Zellweger syndrome and one of three cases of Reye syndrome. The acylcarnitine analysis by FAB/MS showed adipyl-, suberyl-, sebacyl- or dodecanedioylcarnitine as major peaks in most of these patients, although these were not specific. Disease-specific peaks were detectable only in congenital organic acidemias such as glutaric aciduria type II, methylmalonic acidemia and propionic acidemia.     

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??Methylmalonic acidemia??also known as methylmalonic aciduria??is the most common disease of organic acids metabolic disorders. The patients usually present with multi-organic damage. Neurological diseases are common findings. In some patients??kidney disease is one of the complication or the only symptom. Kidney damage due to methylmalonic acidemia needs much attention. Renal damage caused by methylmalonic acidemia is mainly manifested as tubulointerstitial injury. The common manifestations are hematuria??proteinuria??edema and hypertension. If left untreated??the pregressive disease will lead to renal failure. The detection of plasma total homocysteine??blood amino acids??acyl-carnitines and urinary organic acids and genetic analysis are the important methods of etiological diagnosis with methylmalonic acidemia. Most of the patients of methylmalonic acidemia are cobalamin-effective. The renal diseases are reversible. Many patients are improved or get recovery. For the patients with unexplained renal diseases??the differential diagnosis should be paid attention to. Early diagnosis and early intervention are keys to improving the outcome of the patients with methylmalonic acidemia.     

A familial progressive neurodegenerative disease with 2-oxoglutaric aciduria

A boy and a girl born to a consanguineous Tunisian couple are suffering from a slowly progressive nervous disorder. Initially they both had normal psychomotor development with acquisition of gait and speech. First symptoms in the boy were athetoid movements during the second year of life. He later lost all motor and language skills and developed muscular rigidity and intention tremor. At the age of five years, he was completely bedridden while he appeared mentally much less affected. His younger sister followed a similar course. The major specific abnormality detected was a strikingly elevated excretion of 2-oxoglutaric acid, which was identified by gas liquid chromatography, mass spectrometry, and enzymatic analysis. 2-oxoglutarate dehydrogenase activity in homogenates of cultured skin fibroblasts was reduced to about 25% of control values in both children. Although the pathogenetic mechanisms leading to brain damage remain obscure, the finding strongly suggest an autosomal recessive neurometabolic disease with predominant involvement of the extrapyramidal system.Supported by Deutsche Forschungsgemeinschaft, SFB33Part of the results was obtained during work for a medical thesis by G. H.     

精氨酰琥珀酸尿症致反复高氨血症1 例报告

目的探讨精氨酰琥珀酸尿症致反复高氨血症的诊断和治疗。方法回顾分析1例精氨酰琥珀酸尿症患儿的诊治及随访经过,并复习相关文献。结果患儿,男,13个月,因呕吐、嗜睡、反应差入院,检查发现血氨升高(138.02μmol/L),肝功能异常,伴低钾血症,血瓜氨酸升高(65.64μmol/L);脑电图异常。完善高氨血症相关基因的二代基因测序,发现精氨酰琥珀酸裂解酶基因(ASL)复合杂合突变。予以限制蛋白饮食、补充精氨酸治疗,患儿高氨血症仍反复发作,肝脏进行性增大;确诊1年后行肝移植。移植后1年,患儿肝功能、血氨无异常,生长发育无异常。结论精氨酰琥珀酸尿症临床表现复杂,高氨血症是其重要表现;基因检查有助确诊,肝移植治疗有效。     

Glutaric aciduria type II: treatment with riboflavine,carnitine and insulin

A boy, now 22 months old, is described who presented at the age of 6 weeks with hypoglycaemic coma. The excretion pattern of organic acids in the urine was consistent with glutaric aciduria type II (GA II). A high energy diet low in fat and protein was given.Treatment with riboflavine resulted in an improvement of the metabolite profile, and the patient gained weight. However, a tendency to hypoglycaemia and severe hypotonia persisted. Due to muscle weakness, aggravated by infections, artificial ventilation was necessary during three periods.Serum carnitine level was low. Treatment with carnitine, started during the third period of artificial ventilation, led to some improvement of muscle strength, but he still could not breathe without support. Treatment with insulin, combined with further enrichment of the diet with glucose, resulted in an increase in muscular strength and in weight gain.Thirteen families with GA II have been described upto now. This is the first patient with a severe form of the disorder wo has survived the 1st year of life. Treatment and metabolic studies are presented.