The American Family Association says National Geographic's decision to feature Avery Jackson on the cover of its January issue is an affront to biblical authority.

It is the first time a transgender person has appeared on the cover of the popular magazine.

Avery, 9 was born a boy but is currently transitioning to be a girl and will appear on the cover of the January issue with the strapline: "The best thing about being a girl is, now I don't have to pretend to be a boy."

She already has a significant following on YouTube, where she documented her story in a video series called 'Avery Chats'.

"When I was born, doctors said I was a boy, but I knew in my heart I was a girl. So I may have some boy body parts, but that's not wrong, that is OK," she says in one video.

In an Editor's Note, National Geographic said the feature reflected the "rapidly" and "radically" shifting beliefs around gender.

"She has lived as an openly transgender girl since age five, and she captured the complexity of the conversation around gender. Today, we're not only talking about gender roles for boys and girls—we're talking about our evolving understanding of people on the gender spectrum," wrote Editor-in-Chief Susan Goldberg. 

National Geographic may be hailing the "gender revolution". However, ASA says the magazine is "shaking a fist at God".

Younger transgender faces have gained increasing media attention, a move the AFA believes is deliberate, and Avery is not the only American transgender child in the spotlight.  Jazz Jennings, also a male transitioning to female, has been the subject of the TLC reality TV show, "I Am Jazz."

The AFA went as far as to say National Geographic's decision to feature such a young transgender person was "abusive."

"National Geographic is the latest print media company to abandon what it does best to foist a lifestyle in the American public that the medical community identifies as unhealthy," said AFA. 

"Imagine the pain and psychological trauma gender dysphoria causes children and adults. Rather than abandoning geography to shame Americans into embracing such a lifestyle, we should be helping individuals who struggle with this disorder. That is, helping confused individuals accept their wonderfully crafted and God-given biology."