A discovery of how stem cells form the neck and shoulders could help babies born with birth defects, say international scientists.
Scans can show up some abnormalities
Although relatively rare, these congenital abnormalities can be severely disabling and even fatal - one has been linked to cot death.
The University College London UK team, working with US and Swedish colleagues, looked at how baby animals developed.
They told Nature tissue development is more complex than thought.
Scientists had thought muscle and bone tissue in the neck and shoulders was made from entirely distinct and separate types of stem cells.
Dr Georgy Koentges and colleagues were able to show this was not the case.
By following the development of animal embryos they found one stem cell group made not only muscles in the neck and shoulder, but also the skeletal structures where these muscles attached.
They believe the findings will shed light on diseases where things go wrong with the development of such structures, such as Klippel-Feil syndrome.
Babies born with this condition have an unusually short neck, low hairline at the back of the head and restricted mobility of the upper spine.
Another birth defect, called Arnold-Chiari malformation, can have even more devastating consequences.
In this condition the base of the skull is abnormally formed which can damage the underlying brain. It has been implicated in around a fifth of cot deaths or sudden infant death syndrome cases, said Dr Koentges.
He said: "Now that we have identified these key players in forming the neck and shoulders we can start looking for the genes that are on in these stem cells.
"We can look at whether these genes are mutated or defective in humans and cause harm."
Dr Sue Kimber, from the School of Biological Sciences at Manchester University, said: "This is indeed a very interesting discovery which will help us to understand the origins of a number of diseases as well as revealing a previously unrecognised mechanism governing development of organs and tissues."
The work was part funded by the Biotechnology and Biological Sciences Research Council.