The study suggests that a critical regulatory gene carried on the Y chromosome increases or decreases the activity of particular gene that determine whether a baby will be male or female.
First author Brittany Croft says the critical gene is called SRY. It induces another gene called SOX9 to trigger the development of testes and high concentrations of SOX9 are required for normal male development.
“However, if there is some disruption to SOX9 activity and only low levels are present, a testis will not develop resulting in a baby with a disorder of sex development.”
