title: Phenotype-genotype correlations of facial width and height proportions in patients with Class II malocclusion.
abstract: OBJECTIVE
  To characterize soft-tissue facial height and width variation in Class II malocclusion and test for correlations with genes HMGA2, AJUBA, and ADK.
  
  
  METHODS
  Nine facial proportions were estimated from 2D frontal repose photographs of 330 Caucasian adults with Class II malocclusion.
  
  
  METHODS
  After adjustments for age and gender, the facial proportions were submitted to a principal component analyses (PCA). The most meaningful phenotypic variations were correlated with SNPs rs7924176 (ADK), rs17101923 (HMGA2), and rs997154 (AJUBA) genotyped in 106 individuals.
  
  
  RESULTS
  Principal component analyses resulted in four principal components (PCs), which explained 75% of total variation. PC1 captured variation in the intercanthus distance and explained 28% of total variation. PC2 explained 21% of the variations in facial taper and facial index. PC3 explained 14% and reflected variations in the vertical dimension of the lower face. PC4 explained 12% and captured variations in distance between the eyes, width of the commissures, and the length of the superior aspect of the lower face height corresponding to the vertical dimension of the philtrum of the upper lip. A suggestive association (p<0.05) was observed between PC4 and rs997154 corroborating the role of AJUBA in variation of facial dimensions.
  
  
  CONCLUSIONS
  2D frontal photographs can be used to derive quantitative measures of soft-tissue phenotypes that are of clinical relevance. The methods described are suitable for discovery and replication of associations between genotypes and malocclusion phenotypes.
authors: Department of Orthodontics, Dows Institute for Research, University of Iowa, Iowa City, IA, USA.
authors: L M
authors: LM
authors: Moreno Uribe
authors: A
authors: A
authors: Ray
authors: D R
authors: DR
authors: Blanchette
authors: D V
authors: DV
authors: Dawson
authors: T E
authors: TE
authors: Southard
mesh_terms: D000293:Adolescent; D000328:Adult; D063405:Anatomic Variation / Q000235:genetics; D002680:Chin / Q000473:pathology; D005123:Eye / Q000473:pathology; D005145:Face / Q000473:pathology*; D005260:Female; D005838:Genotype; D025743:HMGA2 Protein / Q000235:genetics; D006801:Humans; D060588:LIM Domain Proteins / Q000235:genetics; D008046:Lip / Q000473:pathology; D008297:Male; D008312:Malocclusion, Angle Class II / Q000235:genetics / Q000473:pathology*; D008334:Mandible / Q000473:pathology; D008875:Middle Aged; D009666:Nose / Q000473:pathology; D009915:Orbit / Q000473:pathology; D010641:Phenotype; D010781:Photography / Q000379:methods; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D025341:Principal Component Analysis; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D014716:Vertical Dimension; D055815:Young Adult; D015050:Zygoma / Q000473:pathology
chemical_list: C485608:AJUBA protein, human; D025743:HMGA2 Protein; D060588:LIM Domain Proteins; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases
keywords: Class II malocclusion; esthetics; phenotype-genotype correlations