Supernumerary ribs occur most commonly as a cervical rib arising from C7 or a lumbar rib arising from L1. In extremely rare situations, there can be sacral, coccygeal, intrathoracic, or aberrant lumbar ribs 3. Rarely supernumerary ribs (cervical and lumbar ribs aside) have been found as 'normal' anatomic variants, without evidence of any clinical sequelae.
- Turner syndrome
- cleidocranial dysplasia
- Aarskog syndrome
- trisomy 8 syndrome
- incontinentia pigmenti
- fifteen thoracic vertebrae each with a pairs of ribs: isolated case report 5
Supernumerary ribs have been used as a marker for developmental toxicity bioassays in test animals 2.
- 1. Taybi H, Lachman R. Radiology of syndromes, metabolic disorders, and skeletal dysplasias. Mosby. ISBN:0815187092. Read it at Google Books - Find it at Amazon
- 2. Chernoff N, Rogers JM. Supernumerary ribs in developmental toxicity bioassays and in human populations: incidence and biological significance. J Toxicol Environ Health B Crit Rev. 2004;7 (6): 437-49. doi:10.1080/10937400490512447 - Pubmed citation
- 3. Foley WJ, Whitehouse WM. Supernumerary thoracic ribs. Radiology. 1969;93 (6): 1333-4. doi:10.1148/93.6.1333 - Pubmed citation
- 4. Glass RB, Norton KI, Mitre SA, Kang E. Pediatric ribs: a spectrum of abnormalities. (2002) Radiographics : a review publication of the Radiological Society of North America, Inc. 22 (1): 87-104. doi:10.1148/radiographics.22.1.g02ja1287 - Pubmed
- 5. Melhem RE, Fahl M. Fifteen dorsal vertebrae and rib pairs in two siblings. (1985) Pediatric radiology. 15 (1): 61-2. Pubmed