SUN-180 Differential microRNA Expression Profiles in Girls with Idiopathic Central Precocious Puberty and Premature Thelarche

Abstract Disclosure: H. Lee: None. H. Jin: None. Y. Lee: None. Y. Shim: None. H. Jeong: None. I. Hwang: None. Background: Central precocious puberty (CPP) manifests through the activation of the hypothalamic-pituitary-gonadal axis before the age of 8 in girls and is increasing worldwide, but its causes and prevention methods remain mostly unclear. Exaggerated thelarche (ET) and premature thelarche (PT) are variants of early puberty that can be challenging to differentiate from CPP in initial clinical evaluations. Exosomal microRNAs are stable biomarkers capable of crossing the blood-brain barrier. However, human studies on miRNAs in CPP and related conditions remain limited except for increasing miR-30b in boys during puberty. Objective: 1) To investigate the expression profile of exosomal miRNAs in girls with CPP, ET, and PT to explore the potential role of miRNA in puberty onset. 2) To evaluate the expression levels of miR-30b-5p in girls in each group compared to prepubertal controlsMethods: A total of 27 girls were included in this study: 9 with CPP, 4 with ET, 4 with PT, and 10 normal controls. Serum exosomal miRNA was analyzed using next-generation sequencing. Differential miRNA expression analysis between groups was assessed.Results: Clustering and principal component analyses of miRNA expression profiles demonstrated distinct separations among the Control, CPP, and ET groups, indicating significant differences. While the PT group exhibited distinct miRNA expression patterns compared to the control group, it was not clearly separated from the CPP or ET groups. Compared to controls, the CPP group showed 176 upregulated and 142 downregulated miRNAs, the ET group exhibited 175 upregulated and 129 downregulated miRNAs, and the PT group had 156 upregulated and 123 downregulated miRNAs compared to controls. Consistent with findings in pubertal boys, miR-30b-5p was significantly upregulated in CPP, ET, and PT compared to controls.Conclusion: Significant differences in miRNA expression profiles were observed among the CPP, ET, and PT groups compared to the control group. miR-30b-5p is highly expressed in CPP and variants of early puberty in girls. These findings suggest that miRNAs could serve as potential biomarkers for diagnosing and understanding CPP and early puberty. Presentation: Sunday, July 13, 2025