Radial aplasia is a congenital defect which affects the formation of the radius bone in the arm.
A child born with this condition has either a short or absent radius bone in one or both of his or her arms.
Radial aplasia is connected with the condition VACTERL association, under the 'L' for limb malformations.
The cause for radial aplasia is unknown, but is widely believed to occur within the first ten weeks of gestation.
[1] The incidence is reported to be between 1 in 30,000 and 1 in 100,000 live births, bilateral in half, slightly more common in boys than girls.