A study on the conversion between SMN1 and SMN2 genes
10.3760/cma.j.cn511374-20240531-00320
- VernacularTitle:SMN1和 SMN2基因相互转换的研究
- Author:
Qiannan GUO
1
;
Guiyu LOU
;
Li WANG
;
Hongdan WANG
;
Shixiu LIAO
Author Information
1. 河南省人民医院（郑州大学人民医院）医学遗传研究所，郑州 450003
- Publication Type:Journal Article
- Keywords:
Spinal muscular atrophy;
Survival motor neuron;
Survival motor neuron 1 gene;
Survival motor neuron 2 gene
- From:
Chinese Journal of Medical Genetics
2025;42(8):937-942
- CountryChina
- Language:Chinese
-
Abstract:
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.
