ESPE Abstracts

Background: SRS is a typical epigenetic disease. Approximately 40% of patients can not be detected genetic and epigenetic disturbances.

Objective and hypotheses: To analysis whether there is unknown genes or imprinted genes associated with pathogenicity of SRS and to detect the fine mapping SRS hypomethylation position through the Illumina Methylation 450K chip to detect genome-wide methylation differences.

Method: To detect genome-wide methylation sites through the Illumina 450K Infinium Methylation BeadChip chip in 7 cases of SRS diagnosed in Beijing Children’s Hospital and 5 controls matched age. The two methods were validated by using the classical method of sequencing with focal phosphate and digital PCR. Methylation site probe screening standards meet the following 2 points: (1) adjust Pval < 0.05, if adjust Pval≥0.05, the Pval requires less than 0.05 before correction; (2) case vs control Beta-Difference should be not less than 0.2. That is |Beta-Difference| =0.2.

Results: Screening out 116 differential methylation sites in 484821 probes. Through the GO Pathway enrichment analysis, found the cg25963939 site of OSBPL5 was the most significant methylation difference in case group and normal control group (P=0.023, β=−0.243). The classical method of sequencing with focal phosphate and digital PCR validated it. And the gene is located on 11p14 5’UTR region, it is quite possible pathogenic.

Conclusion: Through whole genome methylation chip detection, we found the imprinted gene OSBPL5 detected a significant differential hypomethylation site. OSBPL5 may be related to the pathogenicity of SRS.