Skip to main content
Public beta This website is in public beta – please give your feedback.

Example clinical scenario

A four-year-old girl is referred to paediatrics from primary care with a moderate learning disability (delayed motor milestones, some single words but limited sentences) in association with a height over the 98th centile (2.2 standard deviations (2.2SD) above the mean) and a head circumference over the 99.6th centile (3.1SD above the mean). She has subtle dysmorphic features, including up-slanting palpebral fissures, dolichocephaly and frontal bossing.

When to consider genomic testing

Genomic testing should be considered if:

  • the patient’s height and/or head circumference is at least 2SD above the mean;
  • the patient has dysmorphic features;
  • the patient has developmental delay without a clear aetiology; and/or
  • a specific overgrowth-intellectual disability (OGID) syndrome is clinically suspected. A number of OGID syndromes have been documented, including Sotos syndrome, Weaver syndrome, Tatton-Brown-Rahman syndrome and CHD8 overgrowth syndrome.

What do you need to do?

  • Consult the National Genomic Test Directory. From here you can access the rare and inherited disease eligibility criteria, which contains information about individual tests and their associated eligibility criteria. You can also access a spreadsheet containing details of all available tests.
  • To find out which genes are included on different gene panels, see the NHS Genomic Medicine Service (GMS) Signed Off Panels Resource.
  • Decide which of the panels best suits the needs of your patient or family.
  • For developmental conditions, there are a number of available panels, including:
    • R29 Intellectual disability: This will investigate chromosomal and single-gene causes of developmental delay and/or intellectual disability (the test is a whole genome sequencing (WGS) panel of all genes known to cause intellectual disability); and
    • R27 Paediatric disorders (children with a suspected OGID are usually tested under this category): This test is a WGS ‘super panel’ (a panel comprised of several different constituent panels forming one large panel), and requesting it currently requires authorisation from clinical genetics services.
  • Note that other panels may also be appropriate – if, for instance, a diagnosis of Beckwith Wiedemann syndrome is suspected, or there is regional (rather than generalised) overgrowth:
  • For tests that are undertaken using WGS, including R27, you will need to:
  • For tests that do not include WGS, including R50, R110 and R263:
    • you can use your local Genomic Laboratory Hub test order and consent (RoD) forms; and
    • parental samples may be needed for interpretation of the child’s result. Parental samples can be taken alongside that of the child, and their DNA stored, or can be requested at a later date if needed.
  • The majority of tests are DNA based, and an EDTA sample (purple-topped tube) is required. Exceptions include karyotype testing and DNA repair defect testing (for chromosome breakage), which require lithium heparin (green-topped tube).
  • Information about patient eligibility and test indications was correct at the time of writing. When requesting a test, please refer to the National Genomic Test Directory to confirm the right test for your patient.

Resources

For clinicians

References:

For patients

↑ Back to top
  • Last reviewed: 16/04/2024
  • Next review due: 16/04/2025
  • Authors: Professor Kate Tatton-Brown
  • Reviewers: Dr Elaine Clark, Dr Eleanor Hay, Dr Adam Jackson