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Transmission characteristics of SMN from 227 spinal muscular atrophy core families in China

Journal of Human Genetics volume 65, pages 469–473 (2020)Cite this article

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Abstract

To define the relationship between the survival motor neuron 1 gene (SMN1) and SMN2, and explore the variability of these two genes within the generations, SMN1 and SMN2 copy numbers were determined for 227 SMA families. The association analysis indicated that there was a negative correlation between the copy number of SMN1 and SMN2 (Spearman = −0.472, P < 0.001) in 227 SMA children and 454 of their parents. The average SMN copies from father and mother in each SMA family were used to represent the copy number in the parent’s generation. Subsequently, SMN transmission analysis showed that the similar distribution trend of SMN1 and SMN2 copy number was not only in the SMA children and their parents’ generation but also in the non-SMA families. Moreover, when the SMN2 copy number was one in the parent’s generation, 75% of their SMA children had type I and 25% of them had type II/III. However, when the SMN2 copies were three in the parent’s generation, all of their SMA children were type II/III. Therefore, the diversity of SMN copies was mostly inherited and the SMN2 copy number in the parent’s generation could predict the disease severity of SMA children to some extent.

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Acknowledgements

This study was supported by The National Key Research and Development Program of China (2016YFC0901505), CAMS Initiative for Innovative Medicine (CAMS-I2M-1-008), the China Postdoctoral Science Foundation (2018M630108), National Natural Science Foundation of China (81500979), Beijing Natural Science Foundation (5163028, 7172039). And we want to thank the patients and their parents for their collaboration in this investigation.

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  1. Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China

    Yanyan Cao, Yujin Qu, Jinli Bai, Miaomiao Cheng, Yuwei Jin, Hong Wang & Fang Song

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  1. Yanyan Cao
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  2. Yujin Qu
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Correspondence to Fang Song.

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Cao, Y., Qu, Y., Bai, J. et al. Transmission characteristics of SMN from 227 spinal muscular atrophy core families in China. J Hum Genet 65, 469–473 (2020). https://doi.org/10.1038/s10038-020-0730-1

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