Carrier screening for spinal muscular atrophy in 22913 Chinese reproductive age women.

BACKGROUND

To determine the carrier frequency of, and evaluate a carrier screening program for, spinal muscular atrophy (SMA) in reproductive age women in Shenzhen area.

METHODS

A staged screening procedure was used to perform carrier screening for SMA in 22,913 Chinese reproductive age women between 2019 and 2022 in Shenzhen area of China. First, the copy number of exon 7 in the SMN1 gene were detected in women of reproductive age using real-time quantitative polymerase chain reaction. If SMA carriers were detected, their spouses were then recommended to test. Prenatal diagnosis was carried out in couples who were both carriers.

RESULTS

A total of 389 women were found to be SMA carriers (1.70%, 95% CI: 1.53%-1.87%), indicating the carrier prevalence was approximately 1:59. Despite the proportion of nonpregnant women increased from 37.96% in 2019 to 58.18% in 2022 (p < 0.05) among the 22,913 reproductive age women, the recall rate of spouses was still not high (62.21%, 95% CI: 57.39%-67.03%). Eight partners were found to be SMA carriers and two fetuses were determined to have SMA with no copies of the SMN1 gene.

CONCLUSION

Although the acceptability and awareness of SMA carrier screening in Chinese population has increased in recent years, it still fails to reach the ideal expectation. Our experience may provide a basis for and facilitate the popularization of SMA carrier screening in Shenzhen area.