Radial Longitudinal Deficiency
Radial longitudinal deficiency (RLD) is a lack of formation of the thumb side of the upper extremity. It can affect the hand only (usually the thumb) or, more commonly, the hand and forearm. It is a lack of bone, muscle, tendon, nerves, and blood vessels. The severity is different in each affected child.
Dr. Charles Goldfarb discusses radial longitudinal deficiency.