If the defect is of external genital appearance, they are identified at birth, but if the problem is hormonal, they are identified post puberty age when they don't develop gender differentiating features as expected.
One example of a male intersex issue is like for some babies when the testes does not get pushed into the scrotal sacs during childbirth. This means external genital appearance of such babies is not same as normal babies. But let me tell you that the only outcome of this is that sperms are not made properly, which means they can't have babies. This is because optimal temperature of sperm manufacture is a degree less than ideal body temperature hence in normal case, they are outside body cavity.
Else all other hormones and features get built like any other man, because the organ is there and functional and can do everything not dependent on temperature optimisation.
But because of the different appearance, they get called intersex, TG or not-man, and get outcasted.
This is just one example in males. There are countless different types of problems, with or without cures, which end up being typecasted as kinnar.
The exact lacking in Saumya has not been exposed here yet, and she has also been typecasted, primarily because of illiteracy and ignorance.