第二代测序技术诊断球形细胞脑白质营养不良1例报告

Application of next generation sequencing technology for genetic diagnosis of a case with globoid cell leukodystrophy

目的探讨球形细胞脑白质营养不良(Krabbe病)的临床、影像学和GALC基因突变特征。方法回顾分析1例经基因检测确诊的Krabbe病患儿的临床和影像学资料,并应用目标序列捕获和第二代测序技术检测相关基因,采用Sanger测序验证突变位点,并对其父母样本进行突变位点的序列分析。结果患儿男,3岁5个月,为晚发婴儿型,主要临床表现为精神运动发育倒退、抽搐。头颅MRI显示双侧脑室后角旁白质、胼胝体压部、内囊后肢对称性长T1长T2信号。二代测序结果显示患儿GALC基因第15外显子1个杂合突变c.1832T>C和第9外显子1个杂合突变c.979T>G,分别引起氨基酸变化p.L611S和p.F327V,为复合杂合突变。Sanger测序结果显示2个突变分别来源于母亲和父亲,c.1832T>C已有报道,c.979T>G为首次报道。结论通过二代测序技术可以准确检测出Krabbe病的GALC基因突变,可协助临床诊断与鉴别。

Objective To explore the clinical,radiological features and gene mutation of GALC gene in one child withgloboid cell leukodystrophy(Krabbe disease).Methods The clinical and radiological data of a patient diagnosed with Krabbedisease through next-generation sequencing were retrospectively analyzed.Sanger sequencing was used to confirm the results.Results The patient was late infantile form with main manifestations of progressive psychomotor regression and convulsion.Brain MRI showed symmetric long T1and long T2signal changes in the white matter next to lateral ventricle angle,posteriorlimb of internal capsule,and the ministry of corpus callosum.The patient was found to have compound heterozygous mutationsof c.1832T>C in exon15and c.979T>G in exon9,which resulted in amino acid changes of p.L611S and p.F327V,respectively.Sanger sequencing results showed that the two heterozygous mutations were correspondingly inherited from his mother andfather.Conclusions Next-generation sequencing technology is a useful tool for the detection of GALC gene mutation,which isvaluable for definite diagnosis and differential diagnosis of Krabbe disease in clinical practice.