ESPE Abstracts

Objectives: Menarche is defined as the first menstrual bleeding in females, and the age of onset varies and depends on a complex interaction between genetic and environmental factors. The LIN28B gene single nucleotide polymorphisms (SNPs) rs314276, rs7759938 and rs314280 appear to be associated with cases of premature and early menarche. International databases report that the presence of a G allele of rs314280SNP shifts menarche 1.2 months earlier, a C allele of rs314276 SNP 1.44 months earlier and a T allele of the rs7759938 SNP 1.14 months earlier. The aim of this study was to investigate the relationship between the age at menarche (AAM) of girls of Greek origin and the LIN28B gene SNPs rs314276, rs7759938 and rs314280.

Methods: Girls of Greek origin with menarche up to 18 years were included. Both girls and parents or legal guardians were informed and consented to participate in the study. Blood sample was collected and DNA isolation was performed in order to proceed with polymerase chain reaction (PCR) and Sanger sequencing for identification of LIN28B gene SNPs rs314276, rs7759938 and rs314280.

Results: Two-hundred girls were included in this primary analysis. Major allele homozygotes of rs7759938 SNP (TT) were 116/200 (58%) and mean AAM was 11.64 ± 1.58 years, minor allele homozygotes (CC) were 18/200 (9%); mean AAM 11.31 ± 1.29 years and heterozygotes (CT) were 66/200 (33%); mean AAM 11.54 ± 1.56 years. Accordingly, in rs314280 SNP major allele homozygotes (GG) were 77/200 (38.5%); mean AAM 11.47 ± 1.56 years, minor allele homozygotes (AA) were 26/200 (13%); mean AAM 11.57 ± 1.41 years and heterozygotes (GA) were 97/200 (48.5%); mean AAM 11.66 ± 1.58 years. Finally, in rs314276 SNP major allele homozygotes (CC) were 108/200 (54%); mean AAM 11.58 ± 1.71 years, minor allele homozygotes (AA) were 16/200 (8%); mean AAM 11.43 ± 1.8 years and heterozygotes (AC) were 76/200 (38%); mean AAM 11.61 ± 1.24 years. At least one major allele of the SNP rs7759938[T] was present in 74.5% of the population, major allele of rs314280[G] in 63% and major allele of rs314276[C] in 72.8% of the population.

Conclusion: The aforementioned SNPs of the LIN28B gene associated with earlier menarche were found at high rates in our sample. Although the mean age at menarche of the girls was within normal limits, the presence of the major alleles could be used as a basis for further investigation in larger samples.