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Genetic testing for confirmed fanconi anaemia or Bloom syndrome (R229) and cytopenia - fanconi anaemia breakage testing indicated (R258)

Fanconi anaemia and Bloom syndrome are both chromosome breakage/genomic instability syndromes associated with growth retardation and increased cancer susceptibility.

Most of these genes are associated with autosomal recessive mutations, but FANCB is X-linked recessive.

A suggestive diagnosis of Fanconi Anaemia can be obtained by testing for increased chromosome breakage and radial forms. This testing is currently provided by West Midlands Genetics Service under either R258.1 or as a separate test (R260).

For adult referrals with a positive chromosome breakage test, the diagnosis can be confirmed by mutation testing using the R258.2 panel (this panel is also available as a separate test under R229). If the chromosome breakage test is negative, testing using R91 (Cytopenia - not Fanconi anaemia) may be appropriate.

R229 is used following chromosome instability testing (requested using R260) to confirm the diagnosis.

For urgent paediatric pancytopenia referrals, R258.2 (Fanconi anaemia panel) is used in combination with R91 (Cytopenia - not Fanconi anaemia) to increase the chance of reaching a genetic diagnosis within an appropriate timeframe.

Testing strategy

Clinically affected probands

  • R229.1 - analysis for small variants in the small NGS gene panel indicated
  • R229.2 - dosage analysis for copy number variants in the following genes: FANCA;FANCB;FANCD2;PALB2.
  • R258.1 - Fanconi breakage DNA repair defect testing (West Midlands Genetics Service)
  • R258.2 - analysis for small variants in the small NGS gene panel indicated

Genes tested

Genes analysed are in accordance with the 'green' high evidence of clinical association gene list in panel app (see NGS gene panel) R229.1 and R258.2 are identical gene panels

Targeted analysis for known / previously reported familial variants

  • Diagnostic confirmation in individuals at risk of inheriting both previously reported familial pathogenic variants and clinically suspected of having the familial condition (R240)
  • Prenatal diagnosis is available for severe conditions (R240).
  • Segregation studies in affected family members to aid variant interpretation (R375)
  • Carrier testing in relatives of clinically affected patients with an autosomal recessive condition (mutation known) (R244).

Target reporting times

Diagnostic test target reporting time is 84 days.

For other reporting times, please see turnaround times.

Sample requirements and referral information

All referrals should be accompanied by a completed pre-referral form. See referral forms and specimen requirements and referring samples.

Clinical guidance and advice is available to referring clinicians from:

Dr NoƩmi Roy
Consultant Haematologist
John Radcliffe Hospital


Different sample requirements and referral form are required for test R258.1 /R260 which is performed in Birmingham.

Requesting specialties

  • Haematology
  • Immunology
  • Clinical Genetics

Contact details

Haematology specific enquiries can also be emailed.


For other contact details, see contact us.

Price list for non NHSE referrals

Price list for rare disease services (pdf)

Last reviewed:26 April 2024