医学外显子测序技术在严重胎儿生长受限产前诊断中的应用

Application of medical exome sequencing technology in prenatal diagnosis of severe fetal growth restriction

摘要

目的 探讨医学外显子测序技术在严重胎儿生长受限(FGR)产前诊断中的应用价值。方法 收集2021年1月至2023年9月在南方医科大学第十附属医院(东莞市人民医院)就诊,并进行介入性产前诊断,行染色体核型分析、微阵列分析结果阴性,且排除TORCH异常的32例严重FGR的胎儿进行医学外显子测序.按是否合并超声异常,将其分为单纯严重FGR组21例,严重FGR合并其他超声异常组11例;并对两组医学外显子测序结果进行分析。结果 在32例严重FGR病例样本中,羊水样本30例,脐血样本2例.通过医学外显子测序检出致病性/可疑致病性(P/LP)基因变异(FGFR2、CREBBP、COL1A1、PRRT2、GJB2)6例,检出率为18.8%,其中检出与严重FGR相关致病性/可疑致病性基因突变3例(病例1、病例2、病例3),检出率为9.4%;意外发现与超声表型不相关的致病性/可疑致病性基因突变3例(病例4、病例5、病例6),检出率为9.4%;检出临床意义未明基因变异4例(病例7、病例8、病例9、病例10),检出率为12.5%,突变基因主要包括:IHH、BMPR2、ATP2B1、SLC25A13.在单纯严重FGR组中,检出与严重FGR相关致病性/可疑致病性基因突变2例,检出率为9.5%;在严重FGR合并其他超声异常组中,检出与严重FGR相关致病性/可疑致病性基因突变1例,检出率为9.1%。结论 医学外显子检测有助于发现染色体核型微阵列分析无法检出的单基因突变,有利于提高对严重FGR遗传病因的诊断.

Abstract

Objective To investigate application value of medical exome sequencing technology in prenatal diagnosis of severe fetal growth restriction (FGR). Methods A total of 32 fetuses with severe FGR who underwent invasive prenatal examination and had negative results of chromosome karyotype analysis and microarray analysis (those with abnormal TORCH detection result were excluded) in The Tenth Affiliated Hospital of Southern Medical University/Dongguan Municipal People's Hospital from January 2021 to September 2023 were selected in the study. According to whether the fetus had ultrasound abnormalities, the fetuses were divided into simple severe FGR group (n=21) and severe FGR concurrent with ultrasound abnormalities group (n=11). The medical exome sequencing results of the fetuses in the two groups were analyzed. Results Among the 32 cases, including 30 amniotic fluid samples and 2 umbilical cord blood samples, 6 cases of pathogenic or likely pathogenic gene variants (FGFR2, CREBBP, COL1A1, PRRT2, GJB2) were detected by medical exome sequencing, with a detection rate of 18.8%. Among them, 3 pathogenic (P)/likely pathogenic (LP) gene variations detected (case 1, case 2 and case 3) were related to severe FGR, accounting for 9.4%, and other 3 pathogenic or likely pathogenic gene variations detected (case 4, case 5 and case 6) which were accidentally found were not related to ultrasonic phenotype, accounting for 9.4%. 4 cases of variant of uncertain significance (VUS) (IHH, BMPR2, ATP2B1, SLC25A13) (case 7, case 8, case 9 and case 10) were detected, the detection rate was 12.5%. In the simple severe FGR group, 2 cases of pathogenic/likely pathogenic gene variants (accounting for 9.5%) that were related to severe FGR were detected by medical exome sequencing, and in the severe FGR concurrent with ultrasound abnormalities group, 1 case (accounting for 9.1%) of pathogenic/likely pathogenic gene variant was detected by medical exome sequencing. Conclusion Medical exon sequencing is helpful to find out single gene mutations that cannot be detected by chromosome karyotype microarray analysis, for which it is beneficial to improve genetic etiological diagnosis of severe FGR.

关键词

严重胎儿生长受限 / 外显子测序 / 产前诊断 / 遗传咨询

Key words

severe fetal growth restriction / exome sequencing technology / prenatal diagnosis / genetic counseling

参考文献

[1] 谢幸, 孔北华, 段涛. 妇产科学[M].9版. 北京: 人民卫生出版社, 2018: 135.

[2] Richards S, Aziz N, Bale S, et al. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology[J]. Genet Med, 2015, 17(5): 405-424.

[3] Audette M C, Kingdom J C. Screening for fetal growth restriction and placental insufficiency[J]. Semin Fetal Neonatal Med, 2018, 23(2): 119-125.

[4] Colella M, Frerot A, Novais A R B, et al. Neonatal and long-term consequences of fetal growth restriction[J]. Curr Pediatr Rev, 2018, 14(4): 212-218.

[5] Vaiserman A, Lushchak O. Developmental origins of type 2 diabetes: focus on epigenetics[J]. Ageing Res Rev, 2019, 55: 100957.

[6] Radulescu L, Ferechide D, Popa F. The importance of fetal gender in intrauterine growth restriction[J]. J Med Life, 2013, 6(1): 38-39.

[7] 中华医学会国产医学分会胎儿医学学组. 胎儿生长受限专家共识(2019版)[J]. 中华围产医学杂志, 2019, 22(6): 361-380.

[8] Hu Xuyun, Li Niu, Xu Yufei, et al. Proband-only medical exome sequencing as a cost-effective first-tier genetic diagnostic test for patients without prior molecular tests and clinical diagnosis in a developing country: the China experience[J]. Genet Med, 2018, 20: 1045-1053.

[9] Monaghan K G, Leach N T, Pekarek D, et al. The use of fetal exome sequencing in prenatal diagnosis: a points to consider document of the American College of Medical Genetics and Genomics (ACMG)[J]. Genet Med, 2020, 22(4): 675-680.

[10] 广东省精准医学应用学会遗传病分会. 产前外显子组测序遗传咨询及报告规范(讨论稿)[J]. 中华医学遗传学杂志, 2020, 37(11): 1205-1212.

[11] 娄桂予, 侯巧芳, 杨科. 全外显子组测序技术在产前诊断中的应用专家共识[J]. 中华医学遗传学杂志, 2022, 39(5): 457-463.

[12] Zhou J, Yang Z, Sun J, et al. Whole genome sequencing in the evaluation of fetal structural anomalies: a parallel test with chromosomal microarray plus whole exome sequencing[J]. Genes (Basel), 2021, 12(3): 376.

[13] Fu F, Li R, Li Y, et al. Whole exome sequencing as a diagnostic adjunct to clinical testing in fetuses with structural abnormalities[J]. Ultrasound Obstet Gynecol, 2018, 51(4): 493-502.

[14] Zhou Hang, Fu Fang, Wang You, et al. Genetic causes of isolated and severe fetal growth restriction in normal chromosomal microarray analysis[J]. Gynecol Obstet, 2023, 161: 1004-1011.

[15] Gabriel H, Korinth D, Ritthaler M, et al. Trio exome sequencing is highly relevant in prenatal diagnostics[J]. Prenat Diagn, 2021, 42(7): 845-851.

[16] Moosa S, Wollnik B. Altered FGF signaling in congenital craniofacial and skeletal disorders[J]. Semin Cell Dev Biol, 2016, 53: 115-125.

[17] Kosinski P, Luterfk K, Wielgos M. Diaphragmatic hernia as an early ultrasound manifestation of Apert syndrome[J]. Ginekol Pol, 2016, 87(12): 830.

[18] Tan G H, Liu Y Y, Wang L, et al. PRRT2 deficiency induces paroxysmal kinesigenic dyskinesia by regulating synaptic transmission in cerebellum[J]. Cell Res, 2018, 28(1): 90-110.

基金资助

广东省自然科学基金资助项目(2022A1515010359)

广东省粤莞联合项目(2022A1515140168)