title: The prevalence of patients with ocular genetic disorders attending a general paediatric ophthalmology clinic in the East End of London.
abstract: OBJECTIVE
  To document the prevalence of ocular genetic disorders in a general paediatric ophthalmology clinic in a deprived, ethnically diverse inner city area of London, and to assess the consanguineous relationships and ethnicity among families with these conditions.
  
  
  METHODS
  A prospective audit documented all ocular genetic conditions (excluding strabismus and amblyopia) presenting for 16 consecutive weeks to the paediatric ophthalmology clinic. Information regarding ethnicity and consanguinity were sought. The disorders were divided according to the mode of inheritance if known.
  
  
  RESULTS
  Thirteen per cent of patients (45/342) had an ocular genetic disorder or were being examined for one. Of them, 22% (10/45) had a history of consanguinity with an inheritance pattern of 30% autosomal recessive (3/10), 20% autosomal dominant, 50% X-linked/unknown/isolated cases. In the remaining non-consanguineous families (35/45), 22% were autosomal recessive, 17% autosomal dominant, and 60% X-linked/unknown/isolated cases. The vast majority of cases (9/10) with a history of consanguineous marriage had South Asian ancestry. Variable ethnic backgrounds were documented for patients with genetic disease and no consanguinity.
  
  
  CONCLUSIONS
  Ocular genetic disorders are common in secondary care. Less than a third of patients with such disorders had a family history of consanguinity. The proportion of patients with proven autosomal recessive disease was similar irrespective of consanguinity within family. The proportion of children of South Asian ancestry was high in this clinic population.
authors.affiliation: Department of Ophthalmology, Barts and the London (BLT) NHS Trust, London, UK. ashwin.reddy@bartsandthelondon.nhs.uk
authors.forename: M A
authors.initials: MA
authors.lastname: Reddy
authors.forename: R
authors.initials: R
authors.lastname: Purbrick
authors.forename: P
authors.initials: P
authors.lastname: Petrou
mesh_terms: D002648:Child; D003241:Consanguinity; D005128:Eye Diseases / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics*; D005260:Female; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D011204:Poverty Areas; D015995:Prevalence; D011446:Prospective Studies