There were almost 700 referrals to the UK's only clinic for transgender children in 2014, up from 139 in 2010.
Christian Concern has told Premier it has serious worries about the increase in children as young as 10 being offered drugs to halt puberty so they can fully transition to a different gender.
Andrew Marsh from the organisation said on the News Hour: "Children aren't able to drive until their 17, we can't vote until we're 18 and yet we are suggesting that children aged, perhaps 10, are able to make a decision to embark on a course that has huge consequences and significance and life changing implications".
Alex, 15 who was born a boy but is taking medication that pauses puberty and hopes to fully transition to being female, told Sky News: "I've been on (hormone) blockers for 12 to 13 months.
"I was (worried) so much before I took my blockers that my voice would break or I'd develop really masculine features - it wasn't healthy."
There's conflicting opinion on treatment for children with gender dysphoria, when they feel like they should be the opposite sex.
Some medical experts claim there's not enough research into the long term effects of letting treatment happen so early in life.
There are claims the majority of children who experience gender dysphoria as a young person will not go on to become transgender.
But Christina Beardsley from The Sybils, a Christian spirituality group for transgender people, told Premier's News Hour it's good we're listening to children.
She said: "Because I think gender can be so stereotypical and there can be such hard boundaries about it then I think it's really brave of these children to say who they are."
She added that letting children get help early on showed "compassion" from parents and medics.
"It's going to make their lives so much easier as they grow up," she added.
Research by Sky News also found the number of adults undergoing gender reassignment procedures on the NHS has increased by 74% since 2002.