We’re committed to ensuring you have the right information to make genomic test requests in a timely and efficient manner, to deliver the maximum benefit to patients. Below, you can see a number of updates to help you navigate changes easily. We update this page live, as and when changes come through, so make sure to check regularly to see if there’s anything you need to do.

In August 2025, the timelines for the test evaluation process were updated. To learn more about this, please see the guidance on the NHS England website.

The GLH will no longer accept any request for array CGH/SNP array for any test indication in the National Genomic Test Directory (NGTD) where WGS is available. This explicitly includes all individuals who are eligible for R377 (Intellectual disability- microarray only). These patients should now be offered testing by WGS as the first line test. Where parental samples are available the test request should be made as a duo or trio of the proband and available parent(s). Microarray testing should not be requested instead of WGS and should only be requested as first line investigation where there is scientific and clinical utility to do so, following discussion with the GLH e.g. strong clinical suspicion of chromosomal conditions like Williams syndrome, 22q11 deletion.

Please request the R27 (Paediatric disorders) panel instead of the R29 (Intellectual Disability) panel for all developmental delay/ intellectual disability referrals as R27 is a super panel which covers the R29 panel genes and other relevant genes.  Where R29 is requested, the GLH will convert this to R27 unless specifically stated on the test order form that there is a sound clinical reason not to do so.

All requests for R54 (Hereditary Ataxia with adult onset), R56 (Adult onset dystonia, chorea or related movement disorder), R58 (Early onset neurodegenerative disorder) and R60 (adult onset hereditary spastic paraplegia) will have all of these panels applied as a “neurology super panel, R54/R56/R58/R60”, again unless it is stated on the test order form that there is a sound clinical reason not to do so.

Test request forms should stipulate that the test requestor must provide detailed information on how the patient/family meet the eligibility criteria for the test indication that is being requested.

New genetic laboratory request forms that include space to prompt for these details will be issued by the genetic laboratories in C&S region soon. Please use them as soon as they are available to provide the required information. In the interim please add this information to the existing forms. When this information is not provided or is not clear from the referral information, the testing will not proceed. The sample will be stored, and you will be contacted to provide additional information.

Tests should only be requested where there is clear evidence that a result is highly likely to change clinical management of the patient or their family. Management includes determining clinical investigations; and/or therapeutic/treatment decisions or strategies; and/or enrolling in nationally approved surveillance programme; and/or informing and supporting reproductive choices.

Assessing clinical utility of course rests with the clinician making the test request. We are asking you to work with us to manage the very challenging circumstances the GLH laboratories across England now find themselves in.

Non-invasive prenatal testing (NIPT) is only available as indicated through the NHS Fetal Anomaly Screening Programme (FASP) pathway, or where there has been a previous pregnancy with reported whole chromosome trisomy of chromosomes 13, 18 or 21 (see R445 NGTD eligibility criteria). Any other referrals will only be accepted if funded by the patient or the referring centre. Exceptional cases should be discussed with the senior laboratory prenatal team and local clinical genetics. Testing of chorionic villus or amniocentesis samples should be targeted at pregnancies that have received a high chance screening result (unless mitigated by a reassuring NIPT), where there are clinical findings which are suggestive of a genetic condition, or where there is a family history of an eligible genetic condition. All requests must meet NGTD eligibility criteria.

Non-invasive prenatal diagnosis (NIPD) referrals must meet NGTD eligibility criteria. Referrals for recurrence of previous apparently de novo variants without evidence of recurrence will only be accepted if funded by the patient or the referring centre. Where there is a family history of a genetic condition, but prenatal testing would not alter clinical management during the pregnancy, we recommend deferring testing to the postnatal period. Postnatal testing should only be undertaken where there is a high prior likelihood of a positive result with clear clinical utility.

As of November 2025, there are now new test request forms for requesting rare disease genetic testing, and these updated forms should be used for requesting testing. For more information on this, please click here.