|Classification and external resources|
Digital mammogram (Mediolateral view) showing absence of the pectoralis major muscle and architectural distortion on the left side and normal right breast
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 usually also webbing of the fingers (cutaneous syndactyly) of the hand on the same side (the ipsilateral hand). Poland syndrome most often affects the right side of the body, and occurs more often in males than in females.
It was first named in 1962 by Patrick Clarkson, a New Zealand born, British plastic surgeon working at Guy's Hospital and Queen Mary's Hospital, London. He noticed that three of his patients had both a hand deformity and an underdeveloped breast on the same side. He discussed this with his colleague at Guy's Hospital, Dr Philip Evans, who agreed that the syndrome was "not widely appreciated". Clarkson found a reference to a similar deformity published by Alfred Poland, over a hundred years earlier in Guy's Hospital reports, in 1841. Clarkson was able to find the hand specimen dissected by Poland, which was still held in the hospital pathology museum. Poland had dissected a convict called George Elt, who was said to be unable to draw his hand across his chest. Poland noted the chest wall deformity, and this was illustrated in his article; the hand was also dissected and preserved for posterity in Guy's Hospital museum where it remains today. It cannot be truly said that Poland described this syndrome because he only described one isolated case. Clarkson published his series of three cases and named the syndrome after Poland in his article.
According to the National Human Genome Research Institute, Poland syndrome affects males three times as often as females and affects the right side of the body twice as often as the left. The incidence is estimated to range from one in 7,000 to one in 100,000 live births.
The cause of Poland syndrome is unknown. However, an interruption of the embryonic blood supply to the arteries that lie under the collarbone (subclavian arteries) at about the 46th day of embryonic development is the prevailing theory.
Olympic boxer Jérôme Thomas is also affected by Poland syndrome as his left arm and hand are significantly shorter and smaller than his right. Thomas also lacks a left pectoral muscle.
Fernando Alonso, Formula 1 World Champion. 
Very frequent signs
- Abnormal gastrointestinal tract
- Absent pectoral muscles
- Brachydactyly (Short fingers)
- Diaphragmatic hernia/defect
- Humerus absent/abnormal
- Liver/biliary tract anomalies
- Maternal diabetes
- Oligodactyly/missing fingers
- Radius absent/abnormal
- Rhizomelic micromelia (relatively shorter proximal segment of the limbs compared to the middle and the distal segments)
- Sparcity or abnormality of axillary hair on affected side
- Syndactyly of fingers (webbing)
- Ulna absent/abnormal
- Upper limb asymmetry
- Abnormal rib
- Simian crease on affected side
- Agenesis/hypoplasia of kidneys
- Abnormal morphology of hypothalamic-hypophyseal axis
- Abnormal function of hypothalamic-hypophyseal axis
- Preaxial polydactyly
- Ureteric anomalies (reflux/duplex system)
- Vertebral segmentation anomaly
- Martínez-Frías ML, Czeizel AE, Rodríguez-Pinilla E, Bermejo E (January 1999). "Smoking during pregnancy and Poland sequence: results of a population-based registry and a case-control registry". Teratology 59 (1): 35–8. doi:10.1002/(SICI)1096-9926(199901)59:1<35::AID-TERA8>3.0.CO;2-E. PMID 9988881.
- Karnak I, Tanyel FC, Tunçbilek E, Unsal M, Büyükpamukçu N (February 1998). "Bilateral Poland anomaly". Am. J. Med. Genet. 75 (5): 505–7. doi:10.1002/(SICI)1096-8628(19980217)75:5<505::AID-AJMG9>3.0.CO;2-L. PMID 9489794.
- Maroteaux P, Le Merrer M (December 1998). "Bilateral Poland anomaly versus thoracic dysplasia". Am. J. Med. Genet. 80 (5): 538–9. doi:10.1002/(SICI)1096-8628(19981228)80:5<538::AID-AJMG23>3.0.CO;2-S. PMID 9880227.
- Poland A (1841). "Deficiency of the pectoral muscles". Guy's Hospital Reports VI: 191–193.
- Clarkson P (1962). "Poland’s syndactyly". Guys Hosp Rep 111: 335–46. PMID 14021589.
- "Learning about Poland Anomaly". Retrieved 2007-02-09.
- Fokin A, Robicsek F (2002). "Poland's syndrome revisited". Ann Thorac Surg 74 (6): 2218–25. doi:10.1016/S0003-4975(02)04161-9. PMID 12643435.
- Poullin P, Toussirot E, Schiano A, Serratrice G (1992). "[Complete and dissociated forms of Poland's syndrome (5 cases)]". Rev Rhum Mal Osteoartic 59 (2): 114–20. PMID 1604222.
- Burt, Jennifer (1997-10-20). "Jeremy is a role model for children". Leicester (UK) Mercury.