血浆总同型半胱氨酸测定在智力低下等神经精神异常病因调查中的应用

目的调查原因不明的神经精神异常及甲基丙二酸尿症患儿中同型半胱氨酸血症的发生情况,探讨荧光偏振免疫测定法进行血浆或血清总同型半胱氨酸测定的应用价值。方法对2000年1月至2007年12月因原因不明的智力低下、运动障碍、癫疒间、头痛等多种神经系统异常患儿799例,甲基丙二酸尿症126例患儿,采用荧光偏振免疫测定法检测血液总同型半胱氨酸,气相色谱质谱联用分析测定尿液有机酸,液相串联质谱法进行血液氨基酸、酯酰肉碱谱分析。结果925例高危患儿中共发现同型半胱氨酸血症128例（13.84%）。799例原因不明的神经系统疾病患儿中同型半胱氨酸血症27例（3.38%）,血液丙酰肉碱及游离氨基酸浓度正常。126例甲基丙二酸尿症患儿中合并同型半胱氨酸血症101例（80.16%）,血液丙酰肉碱浓度增高。结论甲基丙二酸尿症合并同型半胱氨酸血症是甲基丙二酸尿症的主要临床表型,为鉴别诊断、正确治疗,应及早进行血液总同型半胱氨酸测定。应用荧光偏振免疫测定法检测血清/血浆总同型半胱氨酸,是同型半胱氨酸血症高危筛查的可靠方法。     

甲基丙二酸尿症合并同型半胱氨酸血症致多系统损害

目的 甲基丙二酸尿症合并同型半胱氨酸血症是甲基丙二酸尿症中的特殊类型,对5例患儿进行回顾性分析,研究本症的临床表现、生化特点、诊断与治疗方法。方法 应用气相色谱-质谱联用分析法（gas chromatography-mass spectrometry,GC-MS）进行尿有机酸分析,采用荧光偏振免疫测定法检测血浆同型半胱氨酸。确诊后给予钴胺素、左旋肉碱、甜菜碱等药物治疗,予以长期随访。结果 5例患儿（男2例,女3例）起病年龄3个月～13岁。4例表现为进行性智力运动障碍伴蛋白尿、血尿,1例因肌肉酸痛就诊,伴抽搐2例,伴周围神经损害2例,肝功异常2例。5例患儿尿甲基丙二酸为29．4～805．9mg／g肌酐（正常对照为0．2～3．6mg／g肌酐）,血浆中同型半胱氨酸42．5～215．22μmol／L（正常对照5～15μmol／L）,均明显增高,血浆游离肉碱浓度下降。经维生素B12左旋肉碱治疗后,患儿尿甲基丙二酸浓度明显下降,经甜菜碱治疗后血浆同型半胱氨酸逐渐降低。结论 甲基丙二酸尿症并同型半胱氨酸血症可导致多系统损害,临床表现多样;早期诊断、早期治疗是改善预后的关键;对不明原因的脑病、周围神经病、肾损害等多脏器损害患者,应尽早进行尿有机酸分析等特殊检查,对于甲基丙二酸尿症患者应进行血浆同型半胱氨酸测定。     

甲基丙二酸尿症cblB型1例及其MMAB基因新突变

cblB缺陷是甲基丙二酸尿症中的罕见类型,该文首次报道1例中国cblB型甲基丙二酸尿症患儿,就其临床经过、血液酯酰肉碱谱、尿液有机酸分析、基因缺陷进行研究.该患儿以代谢性脑病形式起病,液相串联质谱分析显示患儿血液丙酰肉碱显著增高(22.43 μmol/L,参考值 1.0~5.0 μmol/L),丙酰肉碱/乙酰肉碱比值轻度增高(0.51,参考值0.03~0.50),尿液甲基丙二酸(195.41 mmol/mol肌酐,正常值0.2~3.6 mmol/mol肌酐)及其代谢产物浓度增高,血清总同型半胱氨酸浓度正常,符合单纯型甲基丙二酸血症.患儿MUT基因分析未见突变,MMAB基因存在c.562G>A(p.V188M)和c.577G>A(p.E193K)杂合突变,确诊为cblB型甲基丙二酸尿症.其中,c.562G>A为新突变.经羟钴铵肌肉注射、口服左卡尼汀、低蛋白饮食及特殊配方奶粉治疗后,患儿病情逐渐好转.随访至患儿3岁11个月,智力运动明显进步.cblB缺陷患者缺乏特异性症状,临床表型为单纯型甲基丙二酸尿症,可通过代谢筛查及MMAB基因分析获得确诊.     

甲基丙二酸尿症合并同型半胱氨酸血症57例临床分析

目的对57例甲基丙二酸尿症合并同型半胱氨酸血症患者进行回顾性研究。方法1996～2006年就诊的96例甲基丙二酸尿症患者中57例（59.4％）合并同型半胱氨酸血症,来自中国大陆16个省市,其中男32例,女25例,通过尿液、血液生化分析诊断,尿液有机酸测定采用GCMS分析技术,血清、尿液总同型半胱氨酸检测采用荧光偏振免疫测定法。结果57例患者尿中甲基丙二酸均显著增高,血清总同型半胱氨酸81.5～226.5μmol／L（正常对照4.5～12.4μmol／L）,尿液总同型半胱氨酸79.1～414.5μmol／L（正常对照1.0～20.0μmol／L）。其中13例（22.8％）于新生儿期发病,临床表现类似缺血缺氧性脑病;14例（24.6％）于1个月-1岁内发病,以神经系统损害为主要表现;9例（15.8％）于1岁～学龄前发病,以智力运动倒退为主要表现;18例（31.6％）于6～15岁发病,其中7例合并肝、肾、周围神经等多脏器损害。3例（5.3％）分别于16、24、34岁出现进行性智力运动倒退等异常。57例患者中11例（19.3％）死亡。46例（80.7％）接受维生素B12、叶酸、左旋肉碱、甜菜碱补充治疗,逐渐好转,11例（19.3％）完全康复。结论甲基丙二酸尿症合并同型半胱氨酸血症是中国人甲基丙二酸尿症的常见类型,患者个体差异大,可于新生儿期至成年各个时期发病,临床诊断困难。对于甲基丙二酸尿症患者应及早进行血浆、尿液总同型半胱氨酸测定,鉴别诊断,合理治疗。     

甲基丙二酸尿症生化 基因诊断及产前诊断

甲基丙二酸尿症(MMA)是中国最常见的有机酸血症,其生化诊断指标为血丙酰肉碱、丙酰肉碱与乙酰肉碱比值、尿甲基丙二酸及甲基枸橼酸水平增高,合并同型半胱氨酸血症(合并型MMA)血同型半胱氨酸水平增高。已知导致MMA的基因突变主要包括MUT、MMAA、MMAB、MMACHC、MMADHC、LMRD1、HCFC1、MCEE、SUCLG1、SUCLG2及ABCD4,检测到致病变异具有诊断价值。MMA产前诊断主要通过孕妇羊水细胞或胎盘绒毛膜细胞基因突变检测。如果胎儿为MMA,母亲羊水丙酰肉碱与乙酰肉碱比值增高、甲基丙二酸及甲基枸橼酸增高,可以作为此病产前诊断的辅助方法。羊水总同型半胱氨酸检测可作为合并型MMA的产前诊断方法。     

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。     

亚甲基四氢叶酸还原酶缺乏症致脑积水患儿2例临床及MTHFR基因变异分析

目的 探讨以婴儿期脑积水为突出表现的亚甲基四氢叶酸还原酶缺乏症患儿的临床特点、治疗及预后。方法 2例患儿因脑积水于北京大学第一医院儿科就诊，经血清总同型半胱氨酸、血液氨基酸及酰基肉碱谱、尿有机酸和基因分析确诊，对患儿的临床特点、代谢异常、MTHFR基因变异、诊断、治疗及预后等进行回顾性研究。结果 2例患儿为男童，分别于2月龄及4月龄起病，以脑积水及癫痫发作为主要表现，血清总同型半胱氨酸显著增高，血甲硫氨酸降低或处于正常低值，尿有机酸正常，头颅影像检查发现严重脑积水。两患儿服用甜菜碱、亚叶酸钙、钴胺素等治疗后血清总同型半胱氨酸下降，侧脑室腹腔分流手术后颅压改善，但智力运动发育明显迟缓，仍有癫痫发作。两患儿MTHFR基因均存在复合杂合变异，确诊为亚甲基四氢叶酸还原酶缺乏症所致同型半胱氨酸血症2型。4种变异中1种为已知致病变异，3种为未报道的新变异。结论 亚甲基四氢叶酸还原酶缺乏症患儿可于婴儿早期发生脑积水及癫痫等严重神经系统疾病，血清总同型半胱氨酸及基因检测是早期诊断的关键。     

以精神行为异常为首发表现甲基丙二酸尿症合并同型半胱氨酸血症1例报告

<正>甲基丙二酸尿症又称甲基丙二酸血症,是一种常见的遗传代谢性疾病,主要分为8种亚型,即变位酶蛋白缺陷的两种亚型和维生素B12代谢缺陷的6种亚型,其中cbl C、cbl D和cbl F在临床上表现为甲基丙二酸尿症合并同型半胱氨酸血症。本文报道1例以精神行为异常为首发表现的甲基丙二酸尿症合并同型半胱氨酸血症患儿资料,以期提醒临床医师对于有精神行为异常表现的患儿注意     

因预防接种诱发急性脑病的甲基丙二酸尿症cblA型一例

目的 报道1例因预防接种诱发急性脑病的中国甲基丙二酸尿症的cblA型病例.方法 就病例临床、血液酯酰肉碱谱、尿有机酸、甲基丙二酸尿症相关基因等特点进行分析.结果 患儿男,1岁3个月时因“间断呕吐、酸中毒、发育落后8个月”就诊.患儿生后7个月内发育正常,7个月时接种乙肝疫苗后lh出现呕吐、昏迷.临床诊断“中度脱水,电解质紊乱,代谢性酸中毒”,经补液等治疗后好转.此后,患儿发育落后,间断呕吐.1岁3个月时接种百白破疫苗,接种3h后再次出现呕吐,嗜睡,静脉补液后未见好转,7d后喘憋、呼吸困难、昏迷.患儿血液丙酰肉碱16.3μmol/L(参考值1.0 ～ 5.0μmol/L)、丙酰肉碱/游离肉碱0.27(参考值0.03 ～0.25)增高,尿甲基丙二酸(388.21 mmol/mol肌酐,参考值0.2～3.6 mmol/mol肌酐)及其代谢产物浓度显著增高,血浆总同型半胱氨酸浓度正常,符合单纯型甲基丙二酸血症,MMAA基因存在c.650 T＞A(p.L217X)和c.742 C＞T(p.Q248X)复合杂合突变,确诊为cblA型.经羟钴铵肌内注射、左卡尼汀、低蛋白饮食及特殊配方奶粉治疗后,患儿病情逐渐好转.患儿现2岁7个月,智力运动正常.结论 报道我国首例因预防接种诱发急性脑病的cblA型甲基丙二酸尿症.对疑似遗传代谢病患儿,预防接种前的代谢筛查是减少意外的关键.     

经典型同型半胱氨酸尿症13例临床及CBS基因分析

目的分析经典型同型半胱氨酸尿症患儿的临床特点和CBS基因变异情况, 探讨个体化治疗方法及预防。方法回顾性分析2013年11月至2021年6月就诊于郑州大学附属儿童医院及北京大学第一医院儿科的13例经典型同型半胱氨酸尿症患儿的一般情况、临床表现、实验室检查、头颅影像学、CBS基因变异特点、诊断及治疗等资料。结果 13例患儿中男6例, 女7例, 确诊年龄为10日龄至14岁。3例为新生儿筛查检出, 无症状时开始治疗, 余10例于1～6岁发病, 5～14岁时确诊, 主要表现为马凡综合征样体型、晶状体脱位和(或)近视、发育落后、骨质疏松及心脑血管疾病。4例脑磁共振成像示不对称梗死灶, 1例示髓鞘形成低下。13例患儿血清蛋氨酸、血清总同型半胱氨酸及尿液总同型半胱氨酸均增高, 尿液甲基丙二酸正常, 符合经典型同型半胱氨酸尿症。13例患儿CBS基因共检出18种变异, 其中10种为新变异、8种为已知变异。仅1例为维生素B6部分反应型, 12例为维生素B6无反应型, 均以低蛋氨酸饮食及甜菜碱治疗为主, 3例疗效不良患儿分别于3、8、8岁进行了肝移植治疗, 术后1周内血液蛋氨酸及同型半胱氨酸恢复正常。1例患...     

A rare inborn error of intracellular processing of cobalamine presenting with microcephalus and megaloblastic anemia: a report of 3 children

INTRODUCTION: Defects of methionine synthase or methionine synthase reductase result in an impaired remethylation of homocysteine to methionine. Patients present with megaloblastic anemia, failure to thrive and various neurological manifestations including mental retardation, cerebral atrophy, muscular hypotonia or hypertonia, ataxia, seizures, nystagmus and visual disturbances. PATIENTS: We report on three children (two girls, one boy), aged 3.5-7.5 years, who presented with severe megaloblastic anemia, micro-cephalus and partly nystagmus (2/3) due to a rare inborn error of remethylation. RESULTS: Methionine synthase reductase deficiency, cblE type of homocystinuria (OMIM 236270), is a rare autosomal recessive inherited disorder described only in 14 patients worldwide. Metabolic hallmarks of the disease are hyperhomocysteinemia (median 98 micromol/l, normal range <15) without methylmalonic aciduria but often hypomethioninemia. The patients described here were diagnosed at ages of 2-18 months. The importance of an early recognition of this possibly underdiagnosed congenital disease is stressed. Treatment consisted of the application of hydroxocobalamine (1-2 mg weekly, i.m.), betaine (100-200 mg/kg daily, p.o.), folate (5-10 mg daily, p.o.) and intensive physical therapy. CONCLUSION: Defects of intracellular processing of cobalamine must be considered in all patients with neurological symptoms in combination with megaloblastic anemia. Measurements of homocysteine and methionine in plasma as well as methylmalonic acid in urine is required for confirming the diagnosis. Early treatment im-proves the outcome, although mental disability may not be prevented. Treatment has a positive impact on megaloblastic anemia but only slight effect on hyperhomocysteinemia. The long-term cardiovascular risk of hyperhomocysteinemia in cblE deficient patients is not known yet.     

以急性脑干脑炎及脊髓炎起病的单纯型甲基丙二酸尿症1例

MUT 基因突变引起的甲基丙二酰辅酶A 变位酶缺陷是我国单纯型甲基丙二酸尿症的主要病因。该文报道我国首例以急性脑干脑炎和脊髓炎样形式起病的MUT 型患者,探讨甲基丙二酸尿症的复杂临床表型。患儿,女,3 岁2 个月时因发热伴肢体进行性无力3 d,呼吸困难伴意识障碍1 d 就诊。头颅MRI 扫描提示双侧苍白球及脑干背侧对称片状高信号,脊髓MRI 扫描提示急性脊髓炎样改变。临床诊断为"病毒性脑炎、中枢型呼吸衰竭?",血液丙酰肉碱(6.83 μmol/L,参考值1.0~5.0 μmol/L)增高,尿甲基丙二酸(133.2 mmol/mol肌酐,参考值 0.2~3.6 mmol/mol 肌酐)显著增高,血清总同型半胱氨酸正常。MUT 基因存在c.1663C>T 和c.1630_1631GG>TA 突变,其中c.1663C>T(p.A555T)为新突变,确诊为MUT 型甲基丙二酸尿症。经特殊饮食、维生素B12、左卡尼汀治疗后,患儿病情逐渐好转。甲基丙二酸尿症临床表现复杂,早期的代谢筛查及基因诊断是鉴别病型、指导治疗的关键技术。     

Intact recovery from early 'acquired methylmalonic aciduria' secondary to maternal atrophic gastritis

Aim: A 6‐month‐old infant with severe hyporegenerative anaemia, muscular hypotonia and developmental delay is reported, and the metabolic, diagnostic and therapeutic implications of this case are discussed. Results: Diagnostic work‐up disclosed vitamin B12 depletion with an elevated excretion of methylmalonic acid (MMA), but a normal plasma total homocysteine. MRI showed fronto‐temporal atrophy and a delay in myelinization. The boy’s disease was attributable to a maternal atrophic gastritis. After initiation of vitamin B12 supplementation, he quickly recovered regarding haematopoiesis and MMA excretion. His neurological development completely normalized during 18 months of follow‐up including assessment by Bayley scores. Conclusion: As the majority of reported patients with this acquired form of methylmalonic aciduria show a persistent neurological deficit, early diagnosis of this condition is mandatory and should include sensitive markers of vitamin B12 depletion, namely MMA formation and plasma homocysteine.     

Neonatal onset methylmalonic aciduria and homocystinuria:Biochemical and clinical improvement with betaine therapy

Methylmalonic aciduria and homocystinuria is a very rare inborn error of cellular cobalamin (Cbl) metabolism. We describe the biochemical evolution and clinical course of a boy with neonatal onset CblC mutant defect.Born after a normal pregnancy, the patient developed general hypotonia and severe feeding difficulties at 5 days of life. Diagnosis of methylmalonic aciduria and homocystinuria was established by amino-acid and organic acid analysis and was confirmed by enzyme and genetic studies. The patient was initially treated with parenteral hydroxocobalamin (1 mg/day), oral carnitine (100 mg/kg/day) and a restricted protein diet. This treatment returned methylmalonic acid levels to normal. Despite the parenteral hydroxocobalamin therapy, the patient showed no improvement in neurological dysfunction, hypotonia or developmental delay. Oral betaine supplementation (3 g/day) from months 3-15 reduced plasma total homocysteine and homocystinuria. The patient showed clinical improvement in neurological and growth development. We conclude that early betaine therapy was safe and effective in our patient with neonatal onset methylmalonic aciduria and homocystinuria type CblC.     

幼儿发育落后间断抽搐8个月

该文报道1 例因发育落后及癫癎而诊断为母性苯丙酮尿症(phenylketonuria, PKU)的患儿。患儿男,1 岁8 个月时就诊,发育落后,1 岁出现癫癎,毛发黑,头围小,发育商为43,脑MRI 扫描显示白质髓鞘化发育落后,双侧侧脑室增宽,枕骨大孔狭窄。染色体核型正常,血液氨基酸、酯酰肉碱谱及尿液有机酸正常。家族史调查发现患儿母亲自幼智力落后,学习困难,毛发色泽发黄,26 岁结婚,婚前常规检查未见异常。患儿母亲于28 岁来院检查,血液氨基酸分析发现血液苯丙氨酸显著增高(916.54 μmol/L,正常值20~120 μmol/L),苯丙氨酸羟化酶(PAH)基因c.611A>G(p.Y204C)纯合突变,为PAH 缺陷导致的PKU 患者。患儿为c.611A>G杂合突变携带者,血液苯丙氨酸正常。患儿父亲健康,PAH 基因未检出突变。建议对于不明原因智力障碍的患儿需进行详细的家族史调查,对智力障碍的父母更需进行详细的临床及代谢分析,以发现亲代疾病导致的儿童脑损害,如母性PKU。     

甲基丙二酸尿症合并先天性肾上腺皮质增生症1例报告

目的探讨罕见的甲基丙二酸尿症合并先天性肾上腺皮质增生症患儿的诊疗方法。方法分析1例甲基丙二酸尿症变位酶缺乏合并21羟化酶缺乏症患儿的临床及实验室资料。结果患儿,男,生后3个月起病,接种疫苗及高蛋白饮食后出现喂养困难、腹泻、代谢紊乱及智力运动发育倒退,1岁8个月时确诊为甲基丙二酸尿症,治疗后好转。5岁后出现性早熟表现,确诊为21羟化酶缺乏症男性化型。基因证实MUT基因存在c.866G??C和c.2179C??T两个突变,CYP21A2基因存在c.188A??T和c.518T??A两个已知突变。结论遗传代谢病及内分泌病临床表现复杂,鲜有病例共患多种疾病,该患儿共患甲基丙二酸尿症及21羟化酶缺乏症两种罕见疾病。     

Dravet�ۺ����ٴ���SCN1A����ͻ���������60�����棩

??Objective??To study the clinical features and SCN1A genes detection results in children with Dravet syndrome in order to provide reference for clinical treatment. Methods??The clinical data??SCN1A genes reports and antiepileptic drug effects of 60 DS children who were diagnosed from December 2013 to December 2015 were collected from the Children’s Hospital of Fudan University. Results??The onset of seizures occured during 1-9 months with a median of 6 months and 83.3% of patients were febrile seizures at frist onset??they were heat sensitive??and hot water bath induced seizures in 63.3%??38/60??. There were multiple phenotypes??including generalized tonic-clonic seizures??95.0%??57/60????partial seizures??alternating unilateral seizure????78.3%??47/60????status epilepticus??65.0%,39/60????myoclonic seizures??65.0%??39/60????and atypical absence ??63.3%??38/60??. Seizure ouccurred most frequently??2-3 times per month?? in 1-3 years of age. The median age of mental retardation was 18 months. The number of mental retardation and the positive rate of EEG increased with age. Dravet syndrome were intractable. In patients who used sodium ion blocking drugs 40.0%??24/60?? children had aggravated seizures. 80.0%??48/60?? patients had SCN1A mutation with missense and nonsense mutation accounting for over a half. There was no correlation between SCN1A mutations and onset age??sex??seizure type or seizure frequency. Conclusion??Dravet syndrome is a childhood-onset epileptic encephalopathy??which is not rare in the national seizure center. The positive rate of SCNIA mutation is high??which can help the diagnosis of DS. Anti-epiletic drug treatment for DS is difficult and the misuse of drugs is in a high proportion??so the diagnosis and treatment level still needs to be improved.