Association between SMN2 methylation and disease severity in Chinese children with spinal muscular atrophy

作者:Cao Yan yan; Qu Yu jin; He Sheng xi; Li Yan; Bai Jin li; Jin Yu wei; Wang Hong; Song Fang*
来源:Journal of Zhejiang University-Science B(Biomedicine & Biotechnology), 2016, 17(1): 76-82.
DOI:10.1631/jzus.B1500072

摘要

The homozygous loss of the survival motor neuron 1 (SMN1) gene is the primary cause of spinal muscular atrophy (SMA), a neuromuscular degenerative disease. A genetically similar gene, SMN2, which is not functionally equivalent in all SMA patients, modifies the clinical SMA phenotypes. We analyzed the methylation levels of 4 CpG islands (CGIs) in SMN2 in 35 Chinese children with SMA by MassARRAY. We found that three CpG units located in CGI 1 (nucleotides (nt) -871, -735) and CGI 4 (nt +999) are significantly hypomethylated in SMA type III compared with type I or II children after receiving Bonferroni correction. In addition to the differentially methylated CpG unit of nt -871, the methylation level of the nt -290/-288/-285 unit was negatively correlated with the expression of SMN2 full-length transcripts (SMN2-fl). In addition, the methylation level at nt +938 was inversely proportional to the ratio of SMN2-fl and lacking exon 7 transcripts (SMN2-Delta 7, fl/Delta 7), and was not associated with the SMN2 transcript levels. Thus, we can conclude that SMN2 methylation may regulate the SMA disease phenotype by modulating its transcription.

  • 出版日期2016-1
  • 单位首都儿科研究所