Understanding the dynamics between hormones and genetics to take the best action

Although they suffer from not being able to have any children, people with androgen insensitivity syndrome generally don’t have sexual identity and gender difficulties. They feel female and are attracted to men. “But there are plenty of other problems related to sexual differentiation which are more intermediary and where things are far less clear. For instance, in the case of congenital adrenal hyperplasia, girls are subject to virilisation during embryonic development and can be born with a genital ambiguity”, Julie Bakker points out. Knowing and understanding the interaction between the different hormonal and genetic protagonists leading to sexual differentiation could help people who are faced with these types of problems.

“An important issue that still needs to be cleared up is to find out whether sexual differentiation is complete at birth or whether this continues until puberty", Julie Bakker explains. Recent studies suggest that the brain remains sensitive to sex hormones from an organisational point of view, until puberty (read the article A male or female brain? A question of oestradiol!).

These discoveries call into question the classic theory according to which the brain is masculinised or feminised at birth. “It’s possible that the window during which sexual differentiation takes place is much bigger than the prenatal period. Organisational changes in the brain could occur up to 14 or 15 years old with perhaps a variable influence of hormones on this organisation according to age", Julie Bakker underlines. If this hypothesis turns out to be true, this could have a significant impact on how and when treatment should be given to people suffering from problems relating to the sexual differentiation of the brain. In the near future, Julie Bakker would like to study Kallmann syndrome which lead to problems concerning the neuronal migration of GnRH neurons and an absence or lack of secretion of sex hormones.  “As is often the case in sexual differentiation problems, these people are treated during puberty but perhaps this is too late? Taking action earlier might give better results...”, the researcher concludes.