五个成骨不全家系COL1A1基因的变异分析

目的分析5个成骨不全家系的COL1A1基因致病变异位点,为家系遗传咨询及产前诊断提供依据。方法应用高通量测序方法对5个成骨不全家系的先证者进行225个骨病相关基因进行检测分析,所检岀的可疑变异经PCR扩增后进行Sanger测序,对5个家系的先证者及其家庭成员和100名正常个体进行验证,确定致病性变异后,对1个家系中的高危胎儿进行产前诊断。结果5个家系的先证者分别携带COL1A1基因c.3226G>A(p.Glyl076Ser)杂合错义变异、c.579delT(p.Glyl94Valfs*71)移码变异、c・2911_2912insAG(p.Gly971Glufs*138)插入变异、c.3037G>A(p.Glyl013Arg)杂合错义变异,以及c.642+5G>A杂合剪接变异;家系1胎儿产前诊断结果提示胎儿未携带与先证者相同的变异,与超声检查结果一致。5个家系的父母均未携带相应的变异,均为新发变异。100名正常个体均未检出上述变异。其中COL1A1基因c.3037G>A(p.Glyl013Arg),c.29U_2912insAG(p.Gly971Glufs*138)变异为未报道的新变异。结论COL1A1基因变异是5个成骨不全家系的致病病因。本研究的结果丰富了COL1A1基因的变异谱,为家系遗传咨询和产前诊断提供了依据。

Analysis of COL1A1 gene variants in five Chinese pedigrees affected with osteogenesis imperfecta

Objective To detect potential variants of COL1A1 gene in five Chinese pedigrees affected with osteogenesis imperfecta(OI)and provide prenatal diagnosis for a fetus at 11th gestational week.Methods The coding regions and exon/intron boundaries of 225 genes associated w让h bone diseases were subjected to targeted capture and next generation sequencing(NGS).Suspected mutations were verified with Sanger sequencing in the probands,unaffected relatives and 100 unrelated healthy controls.Prenatal diagnosis for a high-risk fetus was carried out by Sanger sequencing.Results The probands of the pedigrees 1-5 have respectively carried c.3226G>A(p.GlylO76Ser),c.579delT(p.Glyl94Valfs*71),c.2911_2912insAG(p.Gly971Glufs*138),c.30370 A(p.GlylO13Arg)and c.642+5G>A variants of the COL1A1 gene.For pedigree 1,the same variant was not found in the fetus,c.3037G>A(p.GlylO13Arg)and c.2911_2912insAG(p.Gly971Glufs*138)were not reported previously.Conclusion Mutations of the COL1A1 gene probably underlie the OI in the five pedigrees.Combined NGS and Sanger sequencing can provide an effective and accurate method for the genetic and prenatal diagnosis of OI.