nevus

Mr Rhodes was born with a large facial birthmark as a result of congenital melanocytic nevus and was left with scarring following multiple surgeries to remove it as a child.

“Moles are not superficial — the nevus cells are down in the dermis,” said Robert T. Brodell, a tenured professor and chair of the dermatology department at the University of Mississippi Medical Center in Jackson.

Ms Jones, 57, only has the use of one hand following a brain haemorrhage and her 29-year-old son has Asperger's and a rare skin condition called epidermal nevus.

Typically present at birth or soon after, the nevus — which can be anywhere on the body — grows at a similar rate as the child.

How to identify them: These small, round skin growths, which occur when pigment cells grow in clusters, are also called “nevi,” and almost all adults have at least a few.