Home Page
References OMIM Gene GeneReviews HGMD HGNC
last update : 15-06-2013
Symbol ONCR
Location 10q24.31
Name optic nerve colobomas with renal disease
Other name(s)
  • papillorenal syndrome
  • renal coloboma syndrome
  • Corresponding gene PAX2
    related resource Retinal Information Network
    Other symbol(s) ONCRV, RCS
    Main clinical features
  • renal hypoplasia, renal insufficiency, vesicoureteric reflux, and optic disc coloboma
  • renal hypoplasia, renal failure and vesicoureteral reflux, multicystic dysplastic kidney
  • with/without neurosensory deafness, central nervous system anomalies such as Chiari 1 malformation, hydrocephalus and platybasia
  • histologically, kidneys exhibit fewer than the normal number of glomeruli and these glomeruli are enlarged, a finding called oligomeganephronia
  • possible association with a small corneal diameter, retinal coloboma, scleral staphyloma, optic nerve cyst and pigmentary macular dysplasia (PMID: 21654726))
  • Genetic determination autosomal dominant
    Related entries . including the renal coloboma syndrome without vesicoureteral reflux, and any cases of isolated renal hypoplasia
    Function/system disorder congenital malformation
    Type disease
    Gene mutationChromosome rearrangementEffectComments
    deletion   truncated protein deletion in exon 2 of the leading to a truncating mutation and variable phenotype
  • in most cases an expansion of the homonucleotide tracts of guanine (8 or 9G) or exceptionnally a contraction (6G)
  • frameshift mutation located in Exon 8 (G91 I del), which causes premature termination of translation and loss of the PAX2 transactivation domain, associated to renal hypodysplasia or horseshoe kidneys in association with bilateral optic nerve coloboma
  • major pathophysiologic mechanism of the missense mutations is to reduce the stability of PAX2 protein and not to affect the steady state levels of PAX2 mRNA, PAX2 protein localization or the ability of the protein to bind its DNA recognition sequence (hypomorphic alleles of PAX2 can lead to significant disease ) (Alur 2010)