Nijmegen Breakage Syndrome
NBN gene sequencing
Genes
(full coding
region): |
NBN |
Lab method: |
Sanger sequencing |
Specimen requirements: |
2-4 ml of blood with anticoagulant EDTA
1,5 µg DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker. |
Targeted mutation analysis
No of
detectable
markers: |
1 (c.657_661delACAAA (p.Lys219AsnfsTer16)) |
Lab method: |
Sanger sequencing |
Specimen requirements: |
2-4 ml of blood with anticoagulant EDTA
200 ng DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker. |
Indications for genetic testing:
-
- Confirmation of clinical diagnosis
- Carrier status detection of known mutation
- Prenatal diagnosis for known familial mutation
- Genetic counseling
Nijmegen breakage syndrome (NBS) is characterized by progressive microcephaly, recurrent respiratory tract infections, increased risk for cancer, and premature ovarian failure in females. Additional diagnostic criteria include dysmorphic facial features, decline in intellectual ability, growth retardation and short stature.
Approximately 40% of affected individuals have developed malignancies before age 20, predominantly Non-Hodgkin lymphomas of B and T cells, but also solid tumors.
NBS is inherited in an autosomal recessive manner.