What is Poland anomaly?

Named after Sir Alfred Poland, Poland anomaly (PA) is described as an underdevelopment or absence of the chest muscle (pectoralis) on one side of the body and webbing of the fingers (cutaneous syndactyly) of the hand on the same side (ipsilateral hand). Sometimes referred to as "Poland syndrome," it is an uncommon condition present at birth (congenital). For people born with PA, the breastbone portion (sternal) of the pectoralis is also missing.

Since the severity of Poland anomaly differs from person to person, it is not often diagnosed or reported. Sometimes, a person does not realize they have the condition until puberty, when lopsided (asymmetrical) growth makes it more obvious. The incidence, therefore, is difficult to determine. Current estimates are between one in 10,000 to one in 100,000 births. Poland anomaly is more common in boys than girls, and the right side is affected twice as often as the left. The reasons for these differences are unknown.