title: Renal coloboma syndrome.
abstract: OBJECTIVE
  To characterize the ocular features of renal coloboma syndrome.
  
  
  METHODS
  Prospective, observational case series.
  
  
  METHODS
  Twelve patients referred by the pediatric nephrology clinic and the ophthalmic records of five additional patients.
  
  
  METHODS
  For each patient, age at the time of examination, gender, renal function, and presence of a mutation in the PAX2 gene were noted. All patients underwent measurement of visual acuity and anterior and posterior segment examination with fundus photography. Goldmann visual fields were tested in four cases.
  
  
  METHODS
  Visual acuity, optic disc abnormalities, and mutation in the PAX2 gene.
  
  
  RESULTS
  Mean age was 21.5 years. Renal failure was mild in 6 patients and severe in 11 patients. A mutation in the PAX2 gene was identified in nine patients, without correlation to the ocular phenotype. Ocular features could be divided into five groups: optic disc dysplasia limited to an unusual pattern of retinal vessels without functional consequence; optic disc pit with normal visual acuity and blind spot enlargement; large optic disc coloboma; large coloboma of the optic disc and adjacent retina; morning glory anomaly (these last three conditions were accompanied by poor visual acuity). Fundus abnormalities were symmetrical in most cases and unrelated to renal status.
  
  
  CONCLUSIONS
  Ophthalmic and renal characteristics of the renal coloboma syndrome are highly variable. The need for dialysis or renal transplantation can occur early in life or several years later. A wide range of ocular abnormalities located in the posterior segment can be observed. Mild optic disc dysplasia or pit have no functional consequence and can be underdiagnosed. More severe colobomas or related abnormalities, such as morning glory anomaly, often lead to poor visual acuity. Molecular biology allows detection of the mutations in the PAX2 gene, but can be negative in approximately 50% of cases. The observation of an optic disc coloboma or related abnormality stimulates the ophthalmologist to propose simple nephrologic investigations to check for renal hypoplasia, a potentially life-threatening disease. Conversely, renal hypoplasia stimulates the nephrologist to ask for a fundus examination to confirm the diagnosis and check for complications such as retinal detachment.
authors.affiliation: Service d'Ophtalmologie, Hôpital Necker-Enfants Malades, Paris, France. dureau@wanadoo.fr
authors.forename: P
authors.initials: P
authors.lastname: Dureau
authors.forename: T
authors.initials: T
authors.lastname: Attie-Bitach
authors.forename: R
authors.initials: R
authors.lastname: Salomon
authors.forename: O
authors.initials: O
authors.lastname: Bettembourg
authors.forename: J
authors.initials: J
authors.lastname: Amiel
authors.forename: Y
authors.initials: Y
authors.lastname: Uteza
authors.forename: J L
authors.initials: JL
authors.lastname: Dufier
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis* / Q000235:genetics; D000293:Adolescent; D000328:Adult; D002648:Child; D003103:Coloboma / Q000175:diagnosis* / Q000235:genetics; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D007668:Kidney / Q000002:abnormalities* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009898:Optic Disk / Q000002:abnormalities* / Q000473:pathology; D009900:Optic Nerve / Q000002:abnormalities* / Q000473:pathology; D051762:PAX2 Transcription Factor; D010375:Pedigree; D011446:Prospective Studies; D013577:Syndrome; D014157:Transcription Factors / Q000235:genetics; D014792:Visual Acuity
chemical_list: D004268:DNA-Binding Proteins; D051762:PAX2 Transcription Factor; C497318:PAX2 protein, human; D014157:Transcription Factors