Identifying Genetic Eye Disease in Children

The Genetic Eye Disease Committee has recommendations for which children to test and refer:

Genetic Eye Disease in Children

Many of the significant genetic eye disorders in children have at least a partial genetic basis.  Juvenile onset refractive error and strabismus, by far the most common reasons for referral to a pediatric eye doctor, have a large genetic component but do not exhibit classic Mendelian inheritance in which abnormalities in one gene cause one disorder and are passed on directly from parent(s) to child.   Many of the most serious causes of vision loss in the pediatric age group, however, are monogenic, meaning the cause in a given individual can be attributed to mutations in one gene.  These conditions are individually rare, but taken together constitute a large portion of patients seen by pediatric ophthalmologists on a daily basis.  Recognizing genetic eye disorders affords patients and doctors the opportunity for very accurate diagnosis and prognosis, genetic counseling about the risk of recurrence in future children, and potentially gene replacement or causative-gene directed treatment.  It is important for pediatric ophthalmologists to recognize which ocular disorders in children are possibly genetic in order to institute the appropriate workup or refer to a subspecialist for further evaluation.

Which pediatric patients are most likely to have a genetic eye disorder?

Pediatric patients with congenital nystagmus have a very high risk of having a genetic cause for their eye movement disorder.  Congenital nystagmus should be considered a sign, not a diagnosis.  Other disorders likely to be genetic include congenital or developmental cataracts, congenital or juvenile glaucoma, high myopia present prior to preschool, ectopia lentis, pigmentary and flecked retinal disorders optic atrophy and retinoblastoma, whether unilateral or bilateral.  Albinism is a genetic disorder with a broad spectrum of cutaneous and ocular pigment.  Some types of albinism are associated with life-threatening systemic features.

What types of testing are used to diagnose genetic eye disorders?

Diagnosing genetic eye disorders often requires electroretinography, visual evoked potential testing, optical coherence tomography, fundus autofluorescence, visual fields, and other testing as well as molecular genetic testing. 

What are the potential benefits and harms of evaluating patients for genetic eye disorders?

There is an FDA-approved gene therapy treatment for one type of retinal degeneration that typically presents with congenital nystagmus.  There are specific treatments or surveillance protocols for many other genetic eye disorders.  Benefits of diagnostic workup for genetic eye disorders include delivering the best care for that individual’s underlying condition and allowing the family to understand the prognosis and recurrence risk.  Risks include equivocal or non-diagnostic results, misdiagnosis and stress related to receiving a genetic diagnosis. There may be instances in which having a genetic diagnosis increases bias.  Depending on the disorder and type of test, non-paternity may be discovered.

What is the recommendation of the AAPOS Genetic Eye Disease Committee with regard to which children should be evaluated for genetic eye disorders?

Pediatric ophthalmologists should inform patients/parents that the following disorders are likely to be genetic and can be more precisely diagnosed, and in some cases treated, based on further evaluation:

Congenital/infantile nystagmus

Congenital/developmental cataracts

Congenital/juvenile glaucoma

Albinism

High myopia before pre-school age

Ectopia lentis

Low vision or legal blindness without known cause

Retinoblastoma

This list is not complete, and any patient with a family history of an eye disorder should be considered as having a possibly genetic condition. 

What is the recommendation of the AAPOS Genetic Eye Disease Committee with regard to how children should be evaluated for genetic eye disorders?

Pediatric ophthalmologists with the necessary facilities and expertise to institute a workup for genetic eye disorders often complete the workup on their patients.  It is strongly recommended that genetic testing be obtained and discussed with patients in collaboration with a medical geneticist or ophthalmologist specializing in genetic eye disorders as interpretation of testing and counseling are highly complex.  Pre- and post-test genetic counseling is essential. Retinoblastoma patients should be managed in concert with an oncologist.  Even unilateral retinoblastoma may be genetic and should be considered so unless genetic testing determines otherwise.  Pediatric ophthalmologists without the requisite facilities or expertise may inform patients of the potentially genetic nature of the disorder and refer to an ophthalmologist specializing in genetic eye disorders, or a medical geneticist with experience in ocular genetics.

KEY POINTS

  • Pediatric ophthalmologists should be able to identify common conditions as potentially genetic and refer or evaluate
  • Some examples include:
    • Congenital/infantile nystagmus
    • Congenital/developmental cataracts
    • Congenital/juvenile glaucoma
    • Albinism
    • High myopia before pre-school age
    • Ectopia lentis
    • Low vision or legal blindness without known cause
    • Retinoblastoma
  • Referral to an ophthalmologist with genetic expertise and/or a medical geneticist, often in collaboration with a genetic counselor, is crucial to determine:
    • Accurate diagnosis
    • Surveillance and/or treatment if indicated
    • Family planning
  • Suspect a genetic diagnosis and need guidance? Please submit inquiry to AAPOS Genetics Committee via AAPOS