维生素B_2治疗有效的晚发型戊二酸尿症Ⅱ型

Late-onset riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency (glutaric aciduria type Ⅱ)

目的 探讨戊二酸尿症Ⅱ型 (glutaricaciduriatypeⅡ ,GAⅡ )的诊断和治疗。 方法 应用气相色谱 质谱分析技术 (GC MS)对 2例肌无力患儿的尿滤纸片标本进行有机酸分析。确诊为GAⅡ型后 ,在低蛋白、低脂肪、高碳水化合物饮食控制的基础上 ,应用VitB2 进行治疗 ,并观察治疗前后临床、生化及尿有机酸分析等方面的变化。结果 (1)两患儿尿滤纸片标本有机酸分析检出大量戊二酸、异戊酰甘氨酸、乙基丙二酸及己二酸、辛二酸、癸二酸等二羧酸 ,提示为戊二酸尿症Ⅱ型 ;(2 )经饮食控制和VitB2 治疗后 ,2例患儿的肌无力症状明显好转 ,肌力明显增强 ,四肢肌张力恢复正常 ,尿有机酸分析显示上述有机酸的排出量逐步降低、甚至消失 ,血清谷 草转氨酶、肌酸激酶以及乳酸脱氢酶水平均较治疗前显著降低。血氨基本降至正常水平。结论 戊二酸尿症是一种严重的先天代谢障碍性疾病。部分本症患儿在低蛋白、低脂肪、高碳水化合物饮食控制的基础上 ,应用VitB2 进行治疗 ,可取得较好的临床效果。

Objective Glutaric aciduria typeⅡ, or multiple acyl-CoA dehydrogenase deficiency is an autosomal recessively inherited defect of mitochondrial energy metabolism. The authors report two cases of late-onset glutaric aciduria type Ⅱ, and evaluate the procedures for the diagnosis and treatment of this rare disease. Methods The clinical and biochemical characteristics of 2 patients with late-onset glutaric aciduria type Ⅱ were documented. Case 1 presented with lipid storage myopathy for 3 years. Case 2 presented with intermittent episodes of non-ketotic hypoglycemia and muscle weakness for 9 years. The diagnosis of the 2 cases was confirmed with gas chromatography/mass spectrometry analysis of urine samples. Riboflavin supplementation and a low-fat, low-protein, high-carbohydrate diet were initiated as soon as the diagnosis was made. Results Organic acid analysis on both untreated cases revealed massive glutaric acid with elevated concentrations of isovalerylglycine, isobutyrylglycine, ethylmalonic acid, adipic acid, suberic acid and other dicarboxylic acids. The clinical manifestations were improved remarkably after the administration of riboflavin and diet control. Consistent improvements of sera enzymes and urine organic acids were observed during the course of treatment. Conclusion Patients with unexplained myopathy, metabolic acidosis or hypoglycemia should be carefully screened for inherited metabolic disorders. Riboflavin in conjunction with appropriate diet control is an effective therapeutic regime for patients with late-onset glutaric aciduria type Ⅱ.