Baby born with half a skull says hi to supporters

The proud parents of a one-year-old American boy with a rare neural tube condition have posted a video online to thank friends and supporters after doctors gave him only days to live at birth.

Jaxon Buell was born with microhydranencephaly on August 27 last year.

The condition is a severe brain development abnormality and in Jaxon's case is characterised by his small skull.

Fewer than 500 children in the US are born with the condition each year but most of them die shortly after birth.

The video, posted on Facebook by his parents Brittany and Brandon Buell, shows Jaxon lying on the floor when his mum says "Hi baby".

"Hello," the one-year-old replies.

His dad then asks him to say "Hi Germany" which the boy repeats quietly.

"Jaxon says "Hello" to Germany to the kids that drew him pictures!!!!" Jaxon's parents wrote on the Facebook post.

"You can't see our shocked and happy expressions behind the camera, but we are super proud parents to be able to witness Jaxon speaking yet again!!!"

Jaxon's condition has drawn the attention of celebrities including Ashton Kutcher and a GoFundMe page set up for him has so far earned more than $120,000 in donations.