应用第二代测序对一个范可尼贫血家系进行基因突变检测和产前诊断

Molecular and prenatal diagnosis of a family with Fanconi anemia by next generation sequencing

目的对一例范可尼贫血（Fanconi anemia，FA）先证者在母亲再次怀孕时采用第二代测序技术结合Sanger测序验证的方法进行快速诊断，并应用于产前诊断。方法采用全基因外显子组高通量测序方法，分析全基因组外显子数据，在FA相关基因中发现FANCA基因有两个低频致病突变，随后对可疑致病突变进行Sanger测序验证，再对孕母抽取羊水，细胞培养并提取基因组DNA，对FANCA基因做突变检测。结果检测到先证者在FANCA基因中携带母源性e．989_995del（p．H330LfsX2）和父源性C．3971C＞T（p．P1324L）突变，胎儿与先证者均携带此两种突变。结论应用第二代测序技术对一例范可尼贫血患者进行快速亚型分型及基因突变检测，加快了对该患者家系再次生育的产前诊断速度。

Objective To provide prenatal diagnosis for a pregnant woman who had given birth to a child with Fanconi anemia with combined next-generation sequencing （NGS） and Sanger sequencing. Methods For the affected child, potential mutations of the FANCA gene were analyzed with NGS. Suspected mutation was verified with Sanger sequencing. For prenatal diagnosis, genomic DNA was extracted from cultured fetal amniotic fluid cells and subjected to analysis of the same mutations. Results A low-frequency frameshifting mutation c. 989_995de17 （p. H330LfsX2, inherited from his father） and a truncating mutation c. 3971C〉T （p. P1324L, inherited from his mother） have been identified in the affected child and considered to be pathogenic. The two mutations were subsequently verified by Sanger sequencing. Upon prenatal diagnosis, the fetus was found to carry two mutations. Conclusion The combined next- generation sequencing and Sanger sequencing can reduce the time for diagnosis and identify subtypes of Fanconi anemia and the mutational sites, which has enabled reliable prenatal diagnosis of this disease.