title: Dextrocardia in patients with Poland syndrome: phenotypic characterization provides insight into the pathogenesis.
abstract: OBJECTIVE
  Poland syndrome is a rare congenital anomaly characterized by complete or partial agenesis of the pectoralis major muscle variably associated with other thoracic malformations, upper limb malformations, or both. More than 20 patients with dextrocardia and left-sided Poland syndrome have been previously described. The association between these 2 rare anomalies suggests a causal relationship, but the etiopathogenetic mechanism has not been clarified yet. We studied the clinical correlation between these 2 anomalies, and we tried to elucidate whether dextrocardia or Poland syndrome comes first.
  
  
  METHODS
  This is a multicentric multidisciplinary study conducted over the last 5 years. We identified 122 patients with Poland syndrome, and we investigated heart position through different imaging techniques. Logistic regression statistical analyses were carried out.
  
  
  RESULTS
  We observed dextrocardia in 14 (11.5%) patients, which was never associated with situs inversus. All of them presented with left-sided Poland syndrome and partial agenesis of 2 or more ribs. Conversely, all patients with Poland syndrome with partial agenesis of 2 or more ribs presented with dextrocardia, whereas dextrocardia was never associated with partial agenesis of a single rib. Three patients with dextrocardia presented with simple congenital heart defects.
  
  
  CONCLUSIONS
  These findings suggest that mechanical factors during embryonic life could explain the strong association between left-sided Poland syndrome and dextrocardia. According to this hypothesis, partial agenesis of 2 or more ribs is needed to displace the heart toward the right side. The peculiar features of dextrocardia when associated with Poland syndrome (neither associated with situs inversus nor complex intracardiac anomalies) support our hypothesis.
authors.affiliation: Pediatric Surgery Department, Gaslini Children Hospital, Genova, Italy. micheletorre@hotmail.com
authors.forename: Michele
authors.initials: M
authors.lastname: Torre
authors.forename: Anwar
authors.initials: A
authors.lastname: Baban
authors.forename: Anna
authors.initials: A
authors.lastname: Buluggiu
authors.forename: Sara
authors.initials: S
authors.lastname: Costanzo
authors.forename: Lara
authors.initials: L
authors.lastname: Bricco
authors.forename: Margherita
authors.initials: M
authors.lastname: Lerone
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Bianca
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Gatti
authors.forename: Filippo Maria
authors.initials: FM
authors.lastname: Sénès
authors.forename: Maura
authors.initials: M
authors.lastname: Valle
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Calevo
mesh_terms: D000015:Abnormalities, Multiple; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003914:Dextrocardia / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D007558:Italy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D011045:Poland Syndrome / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D018570:Risk Assessment; D012307:Risk Factors; D014463:Ultrasonography; D055815:Young Adult