Clinical application of the single-molecule real-time technology for identification of triplicated α-globin genes and compound variant alleles
10.3969/j.issn.1673-4130.2025.01.008
- VernacularTitle:单分子实时测序在α珠蛋白基因三联体及其复合变异等位基因鉴定中的临床应用
- Author:
Yu ZHANG
1
;
Yanping FANG
;
Biqing ZHU
;
Liyi LIANG
;
Wanjun ZHOU
;
Lingxiao JIANG
Author Information
1. 南方医科大学珠江医院检验医学部,广东 广州 510282;佛山市高明区人民医院检验科,广东佛山 528500
- Keywords:
triplicated α-globin genes;
HKαα;
single-molecule real-time technology;
PCR flow-through hybridization;
next generation sequencing
- From:
International Journal of Laboratory Medicine
2025;46(1):32-37,43
- CountryChina
- Language:Chinese
-
Abstract:
Objective To assess the clinical utility of single-molecule real-time technology(SMRT)in identifying triplicated α-globin genes and compound variant alleles.Methods A total of 36 samples with tripli-cated α-globin genes were collected.Among them,28 samples were confirmed by PCR flow-through hybridiza-tion and 8 samples were confirmed by Next Generation Sequencing(NGS).These 36 samples included tripli-cated α-globin genes compound variants with cis or trans arrangements unknown,such as αααanti4 2 compoundαcsα(2 cases),αααanti4.2 compound-α3.7(10 cases),and HKαα/--SEA pending confirmation(2 cases),SMRT technology was employed to detect thalassemia gene variants.Additionally,a pedigree with the genotype ofαααanti4.2 compound-α3.7 variant was recruited,including the proband(Ⅱ-1),its father(Ⅰ-1),and mother(Ⅰ-2).PCR flow-through hybridization and SMRT were employed to detect thalassemia gene variants.Results SMRT detected 35 out of 36 samples with triplicated α-globin genes,and 1 sample with quadrupllcated α-globin genes(ααααanti4.2).Among the 2 αααanti4 2 compound αCSα variant samples,both αααanti42 and αCSα were arranged in trans,with a genotype of αααanti4.2/αCSα.Among the 10 αααanti4.2 compound-α3.7 variant samples,9 samples hadαααanti4.2 and-α3.7 in a cis arrangement,with a genotype of HKαα/αα,and 1 sample had αααannti4.2 and-α3.7 in a trans arrangement,with a genotype of αααanti4.2/-α3.7.Compared with PCR flow-through hybridization,SMRT detected one case of a large segment deletion in the β-globin gene and two unknown variants,which led to an increase in the positive detection rate of approximately 10.71％(3/28).The pedigree analysis showed that the proband(Ⅱ-1)inherited αααanti4.2 and-α3.7 variants from his mother(Ⅰ-2),with a genotype of HKαα/αα,con-sistent with the SMRT detection results.Conclusion SMRT can accurately detect triplicated or quadrupllcat-ed α-globin genes,and compound variant alleles.It offers high accuracy,enables one-step identification of cis or trans arrangements,and provides comprehensive coverage of thalassemia gene variations,demonstrating its significant clinical value.
