title: A clinical characterization of familial keloid disease in unique African tribes reveals distinct keloid phenotypes.
abstract: BACKGROUND
  This study is a clinical characterization of keloid scars in an African population comprising three rural tribes with familial keloids. Site distribution, morphologic features, and other characteristics of the scars were studied to assess whether each tribe had a specific scar phenotype.
  
  
  METHODS
  Keloid scar clinics were set up at Soba Hospital in Khartoum, Sudan, for patient recruitment and management. In addition, familial keloid cases were recruited from rural tribal populations during field trips. A database including clinical and demographic data and digital photographs of all keloid cases was established. Statistical analysis was conducted using SPSS and SAS software.
  
  
  RESULTS
  One hundred eleven individuals with keloid scarring (67 male subjects and 44 female subjects) were recruited. Patients were predominantly from three multigenerational pedigrees (total of 38 nuclear families) afflicted with keloid scars residing in different rural regions of Sudan. Two distinct morphologic phenotypes of keloid scarring were observed. The first phenotype has been designated "superficial spreading" (horizontal) keloid and the second has been designated "raised" (vertical) keloid. Clinically significant features and statistically measurable morphologic parameters were compared among these phenotypes (p = 0.001). Furthermore, linear claw-like extensions of keloid (transgression) were noted to be significantly higher in the superficial spreading keloid phenotype (p = 0.03).
  
  
  CONCLUSIONS
  There is strong evidence of different phenotypes of keloid scarring. Two distinct phenotypes have been observed, described, and statistically verified. Each tribe demonstrated one particular phenotype, with two being superficial spreading and one being raised. Other significant clinical characteristics have been described. This is of significance in understanding both the clinical basis and the genetic basis of keloid scarring.
authors.affiliation: Manchester, United Kingdom; and Khartoum, Sudan From Plastic and Reconstructive Surgery Research, University of Manchester; Genetic Medicine, University of Manchester, Manchester Academic Health Science Center, Central Manchester University Hospitals NHS Foundation Trust; and the Department of Plastic Surgery, University of Khartoum.
authors.forename: Husam
authors.initials: H
authors.lastname: Bella
authors.forename: Marco
authors.initials: M
authors.lastname: Heise
authors.forename: Khalid I
authors.initials: KI
authors.lastname: Yagi
authors.forename: Graeme
authors.initials: G
authors.lastname: Black
authors.forename: Duncan A
authors.initials: DA
authors.lastname: McGrouther
authors.forename: Ardeshir
authors.initials: A
authors.lastname: Bayat
mesh_terms: D001696:Biomechanical Phenomena; D044383:Black People / Q000208:ethnology / Q000235:genetics*; D005260:Female; D006801:Humans; D007627:Keloid / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D010641:Phenotype; D013397:Sudan