title: Mutation screening of the GUCA1B gene in patients with autosomal dominant cone and cone rod dystrophy.
abstract: BACKGROUND
  Heterozygous mutations in GUCA1A (MIM # 600364) have been identified to cause autosomal dominantly inherited cone dystrophy, cone rod dystrophy and macular dystrophy. However, the role of GUCA1B gene mutations in inherited retinal disease has been controversial. We therefore performed a mutation analysis of the GUCA1B gene in a clinically well characterized group of patients of European and North-American geographical origin with autosomal dominantly inherited cone dystrophy and cone rod dystrophy.
  
  
  METHODS
  Twenty-four unrelated patients diagnosed with cone dystrophy or cone rod dystrophy according to standard diagnostic criteria and a family history consistent with an autosomal dominant mode of inheritance were included in the study. Mutation analysis of all coding exons of the GUCA1B gene was performed by polymerase chain reaction amplification of genomic DNA and subsequent DNA sequencing.
  
  
  RESULTS
  Three different sequence variants, c.-17T>C, c.171T>C, c.465G>T were identified. The sequence variant c.465G>T encodes a conservative amino acid substitution, p.Glu155Asp, located in EF-hand 4, the calcium binding site of GCAP2 protein. All sequence variants were previously reported in healthy subjects.
  
  
  CONCLUSIONS
  The absence of clearly pathogenic mutations in the selected patient group suggests that the GUCA1B gene is a minor cause for retinal degenerations in Europeans or North-Americans.
authors.affiliation: Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany. veronique.kitiratschky@med.uni-tuebingen.de
authors.forename: Veronique B D
authors.initials: VB
authors.lastname: Kitiratschky
authors.forename: Christian Johannes
authors.initials: CJ
authors.lastname: Glöckner
authors.forename: Susanne
authors.initials: S
authors.lastname: Kohl
mesh_terms: D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D005091:Exons / Q000235:genetics; D005799:Genes, Dominant; D051604:Guanylate Cyclase-Activating Proteins / Q000235:genetics*; D006801:Humans; D009154:Mutation / Q000235:genetics*; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology; D016133:Polymerase Chain Reaction; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000235:genetics*
chemical_list: D017931:DNA Primers; C496739:GUCA1B protein, human; D051604:Guanylate Cyclase-Activating Proteins