title: Congential fibrosis of the extraocular muscles type I (CFEOM1) on the Arabian Peninsula.
abstract: OBJECTIVE
  To assess for KIF21A mutation in the first two reported Saudi Arabian families with the classic phenotype of congenital fibrosis of the extraocular muscles type I (CFEOM1).
  
  
  METHODS
  Clinical examination and genetic testing by amplification refractory mutation system (ARMS) assay for KIF21A R954W, the most common KIF21A mutation worldwide.
  
  
  RESULTS
  Clinical examination was consistent with classic CFEOM1 in both Family A and Family B. All participating patients (one child from Family A and four adults from Family B) were heterozygous for KIF21A R954W mutation.
  
  
  CONCLUSIONS
  CFEOM1 is rare is Saudi Arabia as it is in the rest of the world. The finding of R954W mutation in the historically isolated population of the Arabian Peninsula confirms that R954 is a "hotspot" for KIF21A mutation.
authors: Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, KSA. arif.khan@mssm.edu
authors: Arif O
authors: AO
authors: Khan
authors: Dania S
authors: DS
authors: Khalil
authors: Nada A
authors: NA
authors: Al-Tassan
mesh_terms: D000328:Adult; D018912:Arabs / Q000235:genetics*; D001120:Arginine; D001763:Blepharoptosis / Q000235:genetics; D002675:Child, Preschool; D005260:Female; D005355:Fibrosis; D006579:Heterozygote; D006801:Humans; D016547:Kinesins / Q000235:genetics*; D008297:Male; D009135:Muscular Diseases / Q000151:congenital / Q000235:genetics* / Q000473:pathology*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009801:Oculomotor Muscles / Q000473:pathology*; D009886:Ophthalmoplegia / Q000235:genetics; D010375:Pedigree; D012529:Saudi Arabia; D014364:Tryptophan
chemical_list: C119023:KIF21A protein, human; D009419:Nerve Tissue Proteins; D014364:Tryptophan; D001120:Arginine; D016547:Kinesins