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Genetic testing for Nijmegen breakage syndrome (R259)

Nijmegen breakage syndrome is a chromosome breakage/genomic instability syndrome characterised by microcephaly, growth retardation, immunodeficiency and predisposition to cancer, in particular non-Hodgkin lymphoma.

It results from biallelic loss of function mutations in the NBN gene; over 90 percent of patients have the truncating c.657_661del5 pathogenic variant. This disorder is most common in Eastern European Slavic populations (including Poland).

Testing strategy

Clinically affected probands

R259.2 - analysis for small variants in the NBN gene.

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 (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

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


Requesting specialties

  • Haematology
  • Immunology
  • Clinical Genetics

Contact details

See contact us.

Price list for non NHSE referrals

Price list for rare disease services (pdf)

Last reviewed:23 April 2024