Absence of Pectoralis major muscle is the most common skeletal muscle aplasia known.
acro-pectoro-renal field defect - renal ultrasonography is recommended in all children with aplasia of pectoralis major muscle.
Poland syndrome (also Poland's syndrome, Poland's syndactyly, Poland sequence and Poland's anomaly) is a rare birth defect characterized by underdevelopment or absence of the chest muscle (pectoralis) on one side of the body and (but not always) webbing of the fingers (cutaneous syndactyly) of the hand on the same side (ipsilateral hand) mostly common on the right side of body and found more in males than females.
It is usually considered a unilateral condition. Some have claimed that the term can be applied in bilateral presentation, but others recommend using alternate terminology in those cases.