Children can have hundreds of 'satellites'
Congenital melanocytic naevi or CMN is a rare skin disorder involving a concentration of the cells which give pigment to the skin.
These moles are often fragile, hairy and can cover up to 80% of a child's body.
In around 15% of cases, the cells can collect on the brain and spinal cord and children need regular scans to monitor their situation.
There's been very little large-scale research done into CMN and this is where Jeans for Genes is helping.
The charity, Caring Matters Now, has been given a grant towards the maintenance of its patient registry.
By collecting together and updating information about all those who are affected, researchers' work can progress more quickly.
It's a vital source of information to help find out what are the real long-term complications of CMNs and how often they occur. It has also helped to change the management of CMNs.
Jessica Ma from Caring Matters Now said; "We are grateful that Jeans for Genes has awarded us this grant. The patient registry is one of the largest of its kind in the world and is essential to progressing research.
"Jeans for Genes has also given us the opportunity to raise awareness about CMN, to help children deal with the social issues as well as the health issues involved with such a visible condition."