丙酮酸脱氢酶复合物缺乏症一例的临床特点及基因检测

Clinical features of pyruvate dehydrogenase complex deficiency and gene testing in one case

目的 分析1例丙酮酸脱氢酶复合物缺乏症患儿的临床表现及其基因突变特点.方法 对广州医科大学附属广州市妇女儿童医疗中心2013年9-12月确诊的1例丙酮酸脱氢酶复合物缺乏症患儿临床症状、体征特点、生化检测结果、治疗效果进行分析,运用PCR法扩增外周血PDHA1基因的11个外显子及与内含子拼接区,对扩增片段采用直接测序方法检测突变.通过PDHA1基因分析,确诊丙酮酸脱氢酶复合物缺乏症.结果 患儿男,2岁4个月,反复发作性双下肢无力1年余,间断出现抬头无力,独坐不稳,不能独站,持续性高乳酸血症.血乳酸5.37 mmol/L,丙酮酸0.44 mmol/L,乳酸/丙酮酸12.23,脑MRI提示双侧基底节苍白球条状异常信号,T2WI和T2WIFlair高信号.PDHA1基因分析显示,c.788G＞A（p.R263Q）突变,确诊丙酮酸脱氢酶复合物缺乏症.给予生酮饮食、维生素B1、辅酶Q10和左旋肉碱治疗,病情稳定.结论 PDHA1突变所致的丙酮酸脱氢酶复合物缺乏症临床表现复杂多样.PDHA1基因出现c.788G＞A（p.R263Q）突变.对不明原因的肢体无力、高乳酸血症,可通过基因分析诊断.合理治疗可以稳定病情.

Objective To analyze the clinical characteristics and genetype of one children who had been diagnosed with pyruvate dehydrogenase complex deficiency.Method Comprehensive analyses of this case were performed,including clinical symptoms,signs,biochemical examinations and therapeutic effects.The eleven exons and splicing areas of PDHA1 were amplified with genomic DNA from whole blood.And variations were investigated by sequencing the PCR product.The patient was diagnosed with pyruvate dehydrogenase complex deficiency by sequence analysis of PDHA1 gene.Result The patient was a 2 years and 4 monthes old boy.He presented with muscle hypotonia and weakness for one year,and experienced recurrent episodes of unstable head control,unable to sit by himself or stand without support,with persistently hyperlactacidemia.Metabolic testing revealed blood lactate 5.37 mmol/L,pyruvate 0.44 mmol/L,and lactate/pyruvate ratio was 12.23.MRI of the brain showed hyperintense signals on the T2 and T2 Flair weighted images in the basal ganglia bilaterally.Sequence analysis of PDHA1 gene showed a G ＞ A point mutation at nucleotide 778,resulting in a substitution of glutarnine for arginine at position 263 （R263Q）.And the diagnosis of pyruvate dehydrogenase complex deficiency was identified.By giving the therapy with ketogenic diet,vitamin B1,coenzyme Q10 and L-carnitine,the boy was in a stable condition.Conclusion The severity and the clinical phenotypes of pyruvate dehydrogenase complex deficiency varied.Sequence analysis of PDHAI gene revealed a 788G ＞ A （R263Q） mutation.Patients who presented with unexplained muscle hypotonia,weakness and hyperlactacidemia could be diveded by gene analysis.And appropriate treatment can improve the quality of life.