Poland syndrome, also known as Poland sequence or Poland anomaly, consists of many distinctive features. The most prominent among them are ipsilateral hand anomalies chiefly in the form of syndactyly along with absence of pectorals.
Poland syndrome was first described by Alfred Poland in 1841 and includes partial or complete absence of pectoralis along with ipsilateral hand anomalies, ranging from mild defects to severe bony abnormalities. In some cases other associated anomalies, including renal malformations, dextrocardia, and vertebral abnormalities, have been reported.
The incidence rate of the disease ranges from 1:20,000 to 1:50,000 live births. The right side of the body is affected three times more frequently than the left and it is more common in males than in females. The exact etiology of Poland's syndrome is unknown. The theory put forth is interruption of early embryonic blood supply to subclavian arteries, the vertebral arteries and or their branches. A combination of the blockade of various branches could lead to Poland syndrome along with its variants. These vascular disruptions could also lead to its relation with syndromes like Sprengel, Klippel-Fiel and Adams-Oliver syndrome. The inheritance can be autosomal dominant; however variable expressivity and reduced penetrance is usually present.
The gene predisposing to Poland syndrome follows an autosomal dominant pattern of inheritance. There are several cases in the literature demonstrating various types of transmission including father-to-son and mother-to-daughter patterns.