CBS mutation screen
- Description
- Analysis of the CBS gene by PCR amplification and sequencing of the coding region and splice junctions is the gold standard approach.
- Clinical details
- Cystathionine b-Synthase deficiency is an autosomal recessive disorder resulting in homocystinuria - the most common inborn error of methionine metabolism. CBS deficiency results in elevated levels of homocysteine and methionine. The world-wide frequency is reported as ~1:300000 but is highly variable with frequencies as high as 1:65000 in Ireland and 1:20500 in Denmark and as low as 1:800000 in Japan. Causative mutations in the CBS gene are heterogeneous but there are recurrent mutations including the 'Celtic mutation' p.Gly307Ser, responsible for >70% of alleles in patients of celtic origin, and the pan-ethnic p.Ile278Thr, identified in nearly 25% of all CBS alleles.
- Related condition
- Reference range
n/a
- Units
- n/a
- Synonyms
- CBS CBS deficiency Homocystinuria Hyperhomocysteinemia
- Testing site
- Synnovis : Genomics : St Thomas' Hospital
- Laboratory
- Molecular Haemostasis
- Sample type and volume required
- 1 x Edta
- Call in advance
- no
- Storage and transport
- transport at ambient temperature
- Turnaround time
- 8 weeks
- Contacts
Molecular Haemostasis Laboratory at St Thomas’ Hospital
Phone: 020 7188 2798
Haemostasis and Thrombosis
North Wing – 4th floor
St Thomas’ Hospital
Westminster Bridge Road
London SE1 7EH
Laboratory opening times
Monday – Friday 09.00 – 17.00