Clinical analysis and genetic diagnosis of biotinidasedeficiency: a case report and literatures review#br#
MA Xiu-wei, ZHU Li-na, YANG Yao, et al
MA Xiu-wei, ZHU Li-na, YANG Yao, FENG Zhi-chun (Department of Neurology and Development, Affiliated Bayi Children’s Hospital, PLA Army General Hospital, Beijing 100700, China)
Abstract: 【Abstract】Objective To investigate the clinical features, diagnosis and treatment of biotinidase deficiency. Methods The two-month-old male patient was hospitalized in Bayi Children's Hospital affiliated to PLA Army General Hospital in April 2016 because of frequent convulsion for one month. Blood tandem mass spectrometry, urinary organic acid analysis, blood biotinidase activity assay and exome sequencing were performed to confirm the diagnosis. His clinical manifestations, diagnosis and treating process were analyzed. Results Video electroencephalogram (VEEG) showed multiple local discharges and fragmental hypsarrhythmia. The symptom aggravated after administration of sodium valproated. There was no effect to topiramate therapy. Blood tandem mass spectrometry demonstrated that levels of CO, C3 and C5-OH were elevated. Urine organic acid analysis showed that the level of 3 hydroxy isovaleric acid was elevated, with elevated 3 hydroxy acrylic acid, Me-citrate, and Pyroglutamic aid. Biotinidase activity assay on dried blood spot was 0.076 pmol/ (min?3 mm). Exome sequencing revealed that there were c.637delC deletion mutation and c.491dupG insertion mutationin in the exon regions of BTD gene, leading to p.H213fs and p.R164fs amino acid changes. The compound heterozygous mutations were from his parents respectively throughfamily validation. Biotin (10 mg/d) supplementation and l-carnitine (10 ml/d) led to a dramatic effect of the epilepsy. His parents stopped the antiepileptic drugs after discharge. The patient had no convulsion and VEEG was normal at 4-month-old return visit. Gesell test showed that his development quotient was 85. Conclusions Biotinidase deficiency should be considered in infancy with intractable epilepsy and developmental delay. Biotin administration can greatly improve the clinical symptoms. Biotinidase activity assay and gene mutation analysis may be helpful for the definite diagnosis.
基
马秀伟 朱丽娜 杨尧 等. 生物素酶缺乏症的临床分析与基因诊断1例及文献复习[J]. 发育医学电子杂志, 2016, 4(4): 229-235.
MA Xiu-wei, ZHU Li-na, YANG Yao, et al. Clinical analysis and genetic diagnosis of biotinidasedeficiency: a case report and literatures review#br#. Journal of Developmental Medicine(Electronic Version), 2016, 4(4): 229-235.
2016, Vol. 4 
