Which of the following muscle can be congenitally absent?
Poland syndrome is a congenital anomaly in which there is a malformation of the chest causing the pectoralis major on one side of the body to be absent. Other characteristics of this disease are "unilateral shoening of the index, long, and ring fingers, syndactyly of the affected digits, hypoplasia of the hand, and the absence of the sternocostal poion of the ipsilateral pectoralis major muscle". Although the absence of a pectoralis major is not life-threatening, it will have an effect on the person with Poland's syndrome. Adduction and medial rotation of the arm will be much harder to accomplish without the pectoralis major. The latissimus dorsi and teres major also aid in adduction and medial rotation of the arm, so they may be able to compensate for the lack of extra muscle. However, some patients with Poland's syndrome may also be lacking these muscles, which make these actions nearly impossible . Ref -medscape.com
Teres minor
Pectoralis major
Semi-membranous
Palmaris brevis
Upper limb