Presentation: Child with anaemia

A four-year-old girl who has recently moved to England from Nigeria presents to her GP with a history of becoming lethargic and short of breath. She has been having palpitations, and is pale and tachycardic on examination. A full blood count reveals that she is anaemic. The GP therefore refers her to hospital for investigation.

The majority of cases of anaemia in childhood are secondary to dietary insufficiency (such as iron deficiency with microcytosis or vitamin B12 or folic acid deficiency with macrocytosis). The other major causes are anaemias of chronic disease, anaemia of prematurity and iatrogenic anaemias, which occur due to interventions such as chemotherapy or radiotherapy. A subset of anaemias do occur as a result of genetic diseases, and these should be considered when the patient’s full blood count, blood film and family history suggest a underlying genetic cause for their anaemia.

• Ensure an adequate day five blood spot is taken.
• If there are clinical suspicions of sickle cell anaemia or thalassaemia (for example, the patient is a migrant from a country without neonatal screening), consider a blood film examination and referral to a paediatric haematologist.
• Consult the National Genomic Test Directory. From here you can access the rare and inherited disease eligibility criteria, which provides information about individual tests and their associated eligibility criteria. You can also access a spreadsheet containing details of all available tests.
  • For those working within NHS Wales, please consult the All Wales Medical Genomics Service website for information on how to arrange testing.
• 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 haematological disorders, the following tests should be considered (they would need to be requested by a paediatric haematologist):
  • R92 Rare anaemia (multiplex ligation-dependent probe amplification (MLPA), gene panel testing and whole exome sequencing (WES)): The MLPA test will look for copy number variants (CNVs), and gene panel testing and WES will look for small variants.
  • R93 Thalassaemia or other haemoglobinopathies (MLPA and gene panel testing): The MLPA test will look for CNVs, and gene panel testing will look for small variants.
  • R94 Sickle cell anaemia (targeted mutation testing): This will look for small variants.
  • R372 Newborn screening for sickle cell disease in a transfused baby (targeted mutation testing): This will look for small variants.
• Because the above tests do not include whole genome sequencing (WGS):
  • you can use your local Genomic Laboratory Hub test order and consent (record of discussion) forms; and
  • parental samples may be needed for interpretation of the child’s (proband’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.
• For both haemoglobinopathy and DNA-based tests (all the above listed tests), 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.

For clinicians

• Genomics England: NHS Genomic Medicine Service (GMS) Signed Off Panels Resource
• NHS England: National Genomic Test Directory
• Orphanet: Alpha-thalassemia
• Orphanet: Beta-thalassemia
• Patient Info (pro): Thalassaemia

For patients

• Patient Info: Thalassaemia