No Thumb Joint
Aplasia, a condition where a body part fails to develop, can exhibit various levels of underdevelopment or absence. In the case of this individual, they are missing the joint of their thumb entirely.
This rare occurrence results in a unique and unusual condition for this person. Not having the thumb joint can pose challenges in grasping and holding objects. However, like any other obstacle, they have likely found ways to overcome these difficulties and adapt to their situation.