THU161 The Characteristics Of DNA Methylation Pattern In Children Born Small For Gestational Age Who Failed To Catch-up Growth

Abstract Disclosure: M. Kang: None. E. Kwon: None. I. Hwang: None. Introduction: DNA methylation is one of major mechanisms of epigenetic mutation. Differentially methylated regions (DMRs) are found in various imprinting disorders. In this pilot study, we aimed to analyze DNA methylation pattern of short stature children born small for gestational age (SGA-SS). Method: SGA-SS subjects were included when all the following criteria were met: birth weight ≤ 3 percentile; height z-score after age 4 ≤ -1.881 (3 percentile); both parental heights > -1.881 (3 percentile). When the age of subjects were 4.0-7.5 years, they were sorted into SGA-SS group 1 (n=17). Normal control (NC) was age- and sex-matched to SGA-SS group 1 (n=11). NC subjects were normal birth weight (>10 percentile) and normal stature (> 10 percentile). When the height z-score after age 4<-2.5, they were sorted into SGA-SS group 2. DNA methylation patterns of IGF2, H19, PLAG1, MEG3, MEST, SGCE-PEG10, KvDMR genes were performed by pyrosequencing. Result: Mean birth weight and height z-score of NC was 3.3 kg and 0.60, respectively. Mean birth weight SDS and height z-score of SGA-SS group 1 was -2.37 and -2.08, respectively. Mean birth weight SDS and height z-score of SGA-SS group 2 was -2.60 and -2.98, respectively and birth weight was not significantly different compared to that of SGA-SS group 1. Mean DNA methylation levels of IGF2/H19/PLAG1/MEG3/MEST/SGCE-PEG10/KvDMR gene were 58.0/46.8/44.4/55.0/53.2/45.4/48.7%, 55.1/38.2/45.6/53.1/50.6/42.8/47.1%, and 54.4/42.7/45.0/53.6/51.8/44.7/46.3 % in NC, SGA-SS group 1, and SGA-SS group 2, respectively. DNA methylation levels of SGA-SS group 1 were decreased in IGF2 (P=0.027), MEST (P<0.001) compared to those of NC. There was difference of DNA methylation levels of MEST between SGA-SS group 1 and SGA-SS group 2 (P=0.013). Conclusion: DNA methylation levels of SGA-SS groups were different in several candidate genes related to fetal growth compared to those of NC. Although the mechanism of epigenetic mutation is diverse, DNA methylation pattern may have the role in pathophysiology and heterogeneity in SGA children. Presentation: Thursday, June 15, 2023