Shayesteh Jahanfar
Central Michigan University, USA
Title: Age of menarche heritability and birth weight
Biography
Biography: Shayesteh Jahanfar
Abstract
Background: Genetic and environmental factors both influence on age of menarche. However, it is not clear how much of intra-uterine environmental factors particularly sex discordance and birth weight affects the onset of
menarche.
Method: To investigate the genetic and environmental contributions to the association between birth weights with onset of menarche, we studied twins registered at State Washington Twin Registry. A group of female-female
monozygotic (n=994, 497 pairs), female-female dizygotic (n=296, 148 pairs) and females from opposite sex twin sets (n=168) replied to a reproductive health questionnaire. The primary goal of this study was to use a modern
maximum likelihood quantitative genetic method to estimate the heritability (h(2)) of age at menarche. The second goal was to study the role of sex discordance and birth weight on onset of menarche.
Result: After adjusting for birthweight, the monozygotic correlation for age of menarche (0.59) was about 4.21 times the dizygotic correlation (0.14). Birth weight was positively associated with age of menarche (r=0.07, p<0.01) but
not sex discordant.
Conclusion: Age of menarche is genetically determined. From the potential intra-uterine environmental factors, birth weight seems to be related to age of menarche but not sex discordance.