■NTRK1的致病变异可导致先天性无汗症疼痛(CIPA),一种罕见的常染色体隐性遗传性神经病。CIPA的精确诊断依赖于致病性基因型的鉴定。因此,扩展NTRK1变异谱和改进分子诊断方法至关重要。在这项研究中,招募了74名具有典型CIPA表现但基因型未知的先证者。使用包括Sanger和下一代测序在内的技术,进行了全面的分子遗传分析以鉴定NTRK1的变异。生物信息学分析,定量聚合酶链反应(qPCR),gap-PCR,短串联重复序列(STR)基因分型,和逆转录PCR。此外,进行了功能测定以确定不确定意义变体(VUS)的致病性,并进一步表征了14种在TrkA蛋白中不同结构域具有变体的过表达突变载体的糖基化和磷酸化变化,由NTRK1编码。总共确定了NTRK1的48个变异,包括22部小说。结合我们之前研究的另外53CIPA患者的数据,这项研究建立了全球最大的CIPA基因型和表型谱,包括127CIPA家族。此外,功能研究表明,VUS的致病性主要影响细胞外结构域糖基化不足和细胞内结构域异常磷酸化。本研究不仅为PACI的准确诊断提供了重要依据,而且进一步丰富了我们对该病发病机制的认识。
UNASSIGNED: Pathogenic variations in the NTRK1 can cause congenital insensitivity to pain with anhidrosis (CIPA), a rare autosomal recessive inherited neuropathy. The precise diagnosis of CIPA relies on the identification of pathogenic genotypes. Therefore, it is essential to expand the NTRK1 variation spectrum and improve molecular diagnosis methods. In this
study, 74 probands with typical manifestations of CIPA but unknown genotypes were recruited. A comprehensive molecular genetic analysis was performed to identify variations in the NTRK1 , using techniques including Sanger and next-generation sequencing, bioinformatic analysis, quantitative polymerase chain reaction (qPCR), gap-PCR, short tandem repeat (STR) genotyping, and reverse-transcription PCR. In addition, functional assays were conducted to determine the pathogenicity of variants of uncertain significance (VUS) and further characterized changes in glycosylation and phosphorylation of 14 overexpressed mutant vectors with variants at different domains in the TrkA protein, which is encoded by NTRK1 . A total of 48 variations in the NTRK1 were identified, including 22 novel ones. When combined with data from another 53 CIPA patients examined in our previous work, this
study establishes the largest genotypic and phenotypic spectra of CIPA worldwide, including 127 CIPA families. Moreover, functional studies indicated that the pathogenicity of VUS mainly affected insufficient glycosylation in the extracellular domain and abnormal phosphorylation in the intracellular domain. This
study not only provides important evidence for precise diagnosis of CIPA but also further enriches our understanding of the pathogenesis of this disease.