title: Hypothesis: terminal transverse limb defects with "nubbins" represent a regenerative process during limb development in human fetuses.
abstract: BACKGROUND
  Terminal transverse limb defects with nubbins occur in one arm at one of several levels (distal humerus, proximal forearm, wrist, and at the metacarpal-phalangeal joint in the hand). The associated nubbins contain osteocartilaginous tissue and small nails and are not associated with evidence of amnion disruption.
  
  
  METHODS
  We present affected newborn infants whose terminal transverse limb defects are at one of these three levels: proximal forearm, elbow, or metacarpal-phalangeal joint.
  
  
  RESULTS
  We hypothesize that the presence of residual digit-like structures reflects a regenerative process that has occurred during limb development in these infants.
  
  
  CONCLUSIONS
  Only limited regeneration of digit-like structures can occur in the human fetus.
authors.affiliation: Department of Developmental and Cell Biology, University of California Irvine, Irvine, Calif., USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Gardiner
authors.forename: Lewis B
authors.initials: LB
authors.lastname: Holmes
mesh_terms: D001846:Bone Development; D001861:Bone Regeneration / Q000502:physiology*; D001842:Bone and Bones / Q000473:pathology / Q000502:physiology; D002356:Cartilage / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000196:embryology / Q000502:physiology; D004550:Elbow / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000196:embryology / Q000502:physiology; D005260:Female; D005542:Forearm / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000196:embryology / Q000502:physiology; D006225:Hand / Q000473:pathology; D006228:Hand Deformities, Congenital / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D006801:Humans; D007231:Infant, Newborn; D017880:Limb Deformities, Congenital / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000196:embryology / Q000502:physiology; D011247:Pregnancy; D014463:Ultrasonography