Related Experiment Video
Updated: Jan 15, 2026
Evaluation of Exon Inclusion Induced by Splice Switching Antisense Oligonucleotides in SMA Patient Fibroblasts
Published on: May 11, 2018
[A study on the conversion between SMN1 and SMN2 genes]
Qiannan Guo1, Guiyu Lou, Li Wang
1Department of Medical Genetic Center of Henan Provincial People's Hospital (People's Hospital of Zhengzhou University), Zhengzhou, Henan 450003, China. guoqn1984@aliyun.com; ychslshx_hn@aliyun.com.
Objective:
To investigate the steady-state mechanism of interconversion between the SMN1 and SMN2 genes in a normal population.
Methods:
Fluorescence PCR capillary electrophoresis was employed to assess gene conversion and copy number variation of SMN1 and SMN2 in a cohort of 1,133 healthy individuals (including 256 males and 877 females) recruited between 2019 and 2023. This study was approved by the Ethics Committee of Henan Provincial People's Hospital (Ethics No.: 2019-134).
Results:
No significant gender difference was observed in the single copy carrying rate of SMN1. The probability of conversion from SMN1 to SMN2 was determined to be 3.2% for females, 2.7% for males, and 3.1% for the overall population. The probability of conversion from SMN2 to SMN1 was found to be 5.5% for females, 6.3% for males, and 5.6% for the overall population. No statistically significant difference was found in the conversion probability between different genders (P > 0.05). Among the 99 cases of gene conversion, the SMN1 gene predominantly exhibited a copy number of 2 (97.0%), with the remainder having 3 copies (3%). The SMN2 gene primarily showed a copy number of 2 (72.7%), with the rest having 1 copy (27.3%).
Conclusion:
Gene conversion tends to normalize the copy numbers of both SMN1 and SMN2 genes towards 2. However, SMN1 exhibited a higher priority over SMN2, causing the copy numbers approaching two.
