Study on the distribution of FMR1 CGG repeat numbers among 16 610 women of childbearing age in China
10.3760/cma.j.cn101441-20241030-00395
- VernacularTitle:中国16 610例普通育龄女性 FMR1基因CGG重复数的分布情况研究
- Author:
Yahui SHEN
1
;
Wei HOU
;
Xiaolin FU
;
Manli ZHANG
;
Xiaoxiao XIE
;
Chunyan ZHANG
;
Jiaxin BIAN
;
Xiao MAO
;
Juan WEN
;
Chunyu LUO
;
Hua JIN
;
Qian ZHU
;
Qingwei QI
;
Yeqing QIAN
;
Jing YUAN
;
Yanyan ZHAO
;
Ailan YIN
;
Shutie LI
;
Yulin JIANG
;
Rui XIAO
;
Yanping LU
Author Information
1. 中国人民解放军医学院，北京 100853
- Publication Type:Journal Article
- Keywords:
Fragile X syndrome;
FMR1;
Monogenic disease carrier screening;
Prenatal diagnosis;
Genetic counselling
- From:
Chinese Journal of Reproduction and Contraception
2025;45(4):398-402
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the distribution of CGG repeat numbers in the FMR1 gene among reproductive-age women in China, providing data reference for carrier screening and genetic counseling of Fragile X syndrome. Methods:This cross-sectional study recruited 16 610 reproductive-age women from 12 medical institutions between July 2022 and October 2023. Peripheral venous blood samples (3 mL) were collected, and genomic DNA was extracted. The number of CGG repeats in the FMR1 gene was determined using the triplet-primed polymerase chain reaction (TP-PCR) combined with capillary electrophoresis technology. Statistical analyses were performed to assess the prevalence and distribution of CGG repeat expansions. Results:Among 16 610 women of childbearing age, 5 684 (34.220%) women had the same number of CGG repeats in the two alleles of FMR1 gene, and 10 926 (65.780%) women had different numbers of repeats in the two alleles. Among the 33 220 FMR1 alleles in 16 610 women of reproductive age, the most common CGG repeat numbers were 29 [48.645% (16 160/33 220)] and 30 [26.276% (8 729/33 220)], while the most frequent CGG genotype was CGG 29/29 [24.726% (4 107/16 610)]. The CGG repeat numbers of FMR1 gene were normal in 16 498 women (99.326%). Among the 112 women (0.674%) with CGG repeat abnormities, 96 (0.578%) women were classified as intermediate carriers, 15 (0.090%) as premutation carriers, and 1 (0.006%) as a full mutation carrier, whose CGG genotype was (36, >200). Conclusion:In the general reproductive-age female population in China, the normal CGG repeat numbers of the FMR1 gene account for 99.326%, while the intermediate carrier rate is 0.578%, and the combined carrier rate of the premutation and full mutation types is 0.096%.
