应用全外显子测序技术探究家族性表型不一致的平衡易位病例的遗传因果关系。
Exploring the Genetic Causality of Discordant Phenotypes in Familial Apparently Balanced Translocation Cases Using Whole Exome Sequencing.
机构信息
Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, 2371 Nicosia, Cyprus.
Department of Genetics, Alexandra Hospital, 11528 Athens, Greece.
出版信息
Genes (Basel). 2022 Dec 27;14(1):82. doi: 10.3390/genes14010082.
Familial apparently balanced translocations (ABTs) are usually not associated with a phenotype; however, rarely, ABTs segregate with discordant phenotypes in family members carrying identical rearrangements. The current study was a follow-up investigation of four familial ABTs, where whole exome sequencing (WES) was implemented as a diagnostic tool to identify the underlying genetic aetiology of the patients' phenotypes. Data were analysed using an in-house bioinformatics pipeline alongside VarSome Clinical. WES findings were validated with Sanger sequencing, while the impact of splicing and missense variants was assessed by reverse-transcription PCR and in silico tools, respectively. Novel candidate variants were identified in three families. In family 1, it was shown that the de novo pathogenic variant (NM_003165.6:c.1110+2T>G) affected splicing and segregated with the patient's phenotype. In family 2, a likely pathogenic variant (NM_006009.4:c.875C>T, NP_006000.2:p.(Thr292Ile)) could explain the patient's symptoms. In family 3, an variant of uncertain significance (NM_006920.6:c.5060A>G, NP_008851.3:p.(Glu1687Gly)) required additional evidence to sufficiently support causality. This first report of WES application in familial ABT carriers with discordant phenotypes supported our previous findings describing such rearrangements as coincidental. Thus, WES can be recommended as a complementary test to find the monogenic cause of aberrant phenotypes in familial ABT carriers.
家族性明显平衡易位(ABT)通常与表型无关;然而,罕见情况下,携带相同重排的家族成员中 ABT 与不一致的表型分离。本研究是对四个家族性 ABT 的后续调查,其中全外显子组测序(WES)作为一种诊断工具,用于确定患者表型的潜在遗传病因。使用内部生物信息学管道和 VarSome Clinical 分析数据。WES 发现通过 Sanger 测序进行验证,而剪接和错义变体的影响分别通过逆转录 PCR 和计算工具进行评估。在三个家庭中鉴定出了新的候选变体。在家庭 1 中,表明从头致病性变体(NM_003165.6:c.1110+2T>G)影响剪接,并与患者的表型分离。在家庭 2 中,一个可能的致病性变体(NM_006009.4:c.875C>T,NP_006000.2:p.(Thr292Ile))可以解释患者的症状。在家庭 3 中,一个意义未明的变体(NM_006920.6:c.5060A>G,NP_008851.3:p.(Glu1687Gly))需要额外的证据来充分支持因果关系。这是首次报道 WES 在具有不一致表型的家族性 ABT 携带者中的应用,支持了我们之前描述此类重排为偶然的发现。因此,WES 可以作为一种补充测试,用于寻找家族性 ABT 携带者异常表型的单基因病因。