It should go without saying how all children regardless of they being XXY or not, are born Genderless and, will eventually acquire one as they progress through life. Children are actually born with a Sex as in Male, Female, or Intersex. Unlike Gender (Identity) Sex is innate (Biological) and not something any one of us can change, Gender, on the other hand, can be altered and should depend on how the individual views their identity. Just like all other human beings an XXY person should have the right to chose their own identity but, very few get it, even adults who identify their gender as something other than male are only ever offered Exogenous Testosterone, to acquire something else such as Exogenous Estrogen usually involves jumping through all the hoops and loops that are otherwise set aside for Male to Female Transgender people even though we are not Male (sex) and are only seeking access to a hormone with a more gentle impact on our (mostly) sensitive XXY selves.