title: Ophthalmic and molecular genetic findings in Kniest dysplasia.
abstract: OBJECTIVE
  To study the variability of the ophthalmic phenotype in Kniest dysplasia. Kniest dysplasia is an inherited disorder associated with defects in type II collagen and characterised by short-trunked dwarfism, kyphoscoliosis, and enlarged joints with restricted mobility. Other features include marked hand arthropathy, cleft palate, hearing loss, and ocular abnormalities (myopia, abnormal vitreous, and high risk of developing retinal detachment).
  
  
  METHODS
  Data from eight unrelated individuals with a clinical and molecular diagnosis of Kniest dysplasia are reported. Clinical assessment included an audiogram and ophthalmological examination in all but one patient who died in the immediate postnatal period. Sanger sequencing of the COL2A1 gene was performed.
  
  
  RESULTS
  Six of the seven patients tested were high myopes with one patient being an emmetrope. Bilateral quandratic cataracts and subluxed lenses were noted in one subject. Variable but abnormal vitreous architecture was observed in all seven individuals tested. Six of the seven patients had significant hearing impairment and five of the seven patients exhibited clefting abnormalities. One patient had bilateral retinal detachments in his twenties. Six dominant disease-causing COL2A1 variants were detected. In three cases, testing of parental samples revealed that the disease-causing variant was not present in either parent.
  
  
  CONCLUSIONS
  The ophthalmic features in Kniest dysplasia are very similar to those in other disorders of type II collagen such as Stickler syndrome. It is likely that different type II collagenopathies have a similar level of ocular morbidity and regular ophthalmologic examination is recommended. Kniest dysplasia is associated with heterozygous COL2A1 mutations that are frequently de novo.
authors.affiliation: Vitreoretinal Service, Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK.
authors.forename: P I
authors.initials: PI
authors.lastname: Sergouniotis
authors.affiliation: Vitreoretinal Service, Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK.
authors.forename: G S
authors.initials: GS
authors.lastname: Fincham
authors.affiliation: 1] Vitreoretinal Service, Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK [2] Department of Pathology, University of Cambridge, Cambridge, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: McNinch
authors.affiliation: Department of Pathology, University of Cambridge, Cambridge, UK.
authors.forename: C
authors.initials: C
authors.lastname: Spickett
authors.affiliation: Vitreoretinal Service, Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK.
authors.forename: A V
authors.initials: AV
authors.lastname: Poulson
authors.affiliation: 1] Vitreoretinal Service, Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK [2] Department of Pathology, University of Cambridge, Cambridge, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Richards
authors.affiliation: Vitreoretinal Service, Addenbrooke's Hospital, Cambridge University NHS Foundation Trust, Cambridge, UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Snead
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002972:Cleft Palate / Q000235:genetics* / Q000473:pathology; D003095:Collagen Diseases / Q000235:genetics* / Q000473:pathology; D024043:Collagen Type II / Q000235:genetics*; D004392:Dwarfism / Q000235:genetics* / Q000473:pathology; D005128:Eye Diseases / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D005145:Face / Q000002:abnormalities* / Q000473:pathology; D005260:Female; D006311:Hearing Disorders / Q000209:etiology; D006801:Humans; D006819:Hyaline Membrane Disease / Q000235:genetics* / Q000473:pathology; D008297:Male; D009154:Mutation; D010009:Osteochondrodysplasias / Q000235:genetics* / Q000473:pathology; D010641:Phenotype; D055815:Young Adult
chemical_list: C499177:COL2A1 protein, human; D024043:Collagen Type II