Department of Molecular Genetics, Hunan Jiahui Genetics Hospital, Changsha, China.
Department of Reproductive Genetics, Yunnan Maternal and Child Health Care Hospital, Kunming, China.
J Mol Diagn. 2021 Sep;23(9):1195-1204. doi: 10.1016/j.jmoldx.2021.06.008. Epub 2021 Jul 20.
The aim of the study was to assess the clinical utility of a third-generation sequencing (TGS) approach termed comprehensive analysis of thalassemia alleles (CATSA) for identifying both α and β thalassemia genetic carrier status. Prospective blood samples (n = 1759) with abnormal hemoglobin parameters were screened for pathogenic thalassemia variants by CATSA on the PacBio TGS platform. In 1159 individuals, a total of 1317 pathogenic thalassemia variants were identified and confirmed by independent PCR-based tests. Of the total thalassemia variants detected, the α-variant -- (35.4%) and β-variant c.126_129delCTTT (15%) were the most common. CATSA was also able to detect three types of rare HBA structural variants as well as five rare HBA2, three HBA1, and 10 HBB single-nucleotide variations/insertions and deletions. Compared with standard thalassemia variant PCR panel testing, CATSA identified all panel variants present, with no false-negative results. Carrier assignment was improved through identification of rare variants missed by the panel test. On the basis of allelic coverage, reliability, and accuracy, TGS with long-range PCR presents a comprehensive approach with the potential to provide a universal solution for thalassemia genetic carrier screening. It is proposed that CATSA has immediate clinical utility as an effective carrier screening approach for at-risk couples.
本研究旨在评估第三代测序（TGS）方法——全面分析地中海贫血基因（CATSA）——在鉴定α和β地中海贫血遗传携带者状态方面的临床实用性。通过 PacBio TGS 平台上的 CATSA，对具有异常血红蛋白参数的前瞻性血液样本（n=1759）进行致病性地中海贫血变异筛查。在 1159 名个体中，通过独立的基于 PCR 的检测共鉴定和证实了 1317 种致病性地中海贫血变异。在所检测的总地中海贫血变异中，最常见的是 α-变异（35.4%）和 β-变异 c.126_129delCTTT（15%）。CATSA 还能够检测到三种罕见的 HBA 结构变异以及五种罕见的 HBA2、三种 HBA1 和 10 种 HBB 单核苷酸变异/插入和缺失。与标准的地中海贫血变异 PCR 面板检测相比，CATSA 鉴定了所有存在的面板变异，没有假阴性结果。通过鉴定面板检测遗漏的罕见变异，提高了携带者的分配。基于等位基因覆盖、可靠性和准确性，长距离 PCR 的 TGS 提供了一种全面的方法，具有为地中海贫血遗传携带者筛查提供通用解决方案的潜力。有人提出，CATSA 具有即时的临床实用性，是一种有效的高危夫妇携带者筛查方法。
