Molecular detection of the G(-248)A BAX promoter nucleotide change in B cell chronic lymphocytic leukaemia.
BACKGROUND
A novel single nucleotide polymorphism (SNP), G(-248)A, in the 5' untranslated region of the BAX promoter and its association with reduced protein expression, progression beyond Rai stage 0, and treatment resistance in chronic lymphocytic leukaemia (CLL) has been reported previously.


OBJECTIVE
To develop a restriction enzyme analysis (REA) based method for routine detection of BAX promoter SNP in a clinical laboratory.


METHODS
The BAX promoter was analysed in duplicate by REA and sequencing in 90 samples (from 45 patients with CLL, 43 controls, and two cell lines). The promoter region was amplified, digested with restriction endonucleases (Aci I and Tau I), and separated by gel electrophoresis.


RESULTS
After digestion, the normal GG genotype samples produced three distinct bands. The homozygous AA replacement abolished the cleavage site, resulting in a single band. Although the heterozygous samples produced three bands, the two smaller visible bands were reduced in intensity (> 50%). The test characteristics of Aci I REA were better than those of Tau I REA, in terms of sensitivity (100% v 77.8%), specificity (98.6% v 92.3%), positive predictive value (95.03% v 87.4%), and negative predictive value (100% v 85.83%).


CONCLUSIONS
REA using Aci I is a highly sensitive and specific method for detecting the BAX G(-248)A SNP in CLL.
Moshynska
O
O
Department of Pathology, Royal University Hospital and College of Medicine, University of Saskatchewan, Saskatoon SK S7N 0W8, Saskatchewan, Canada.
Sankaran
K
K
Saxena
A
A
D020121:5' Untranslated Regions / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005819:Genetic Markers; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D000091402:Prohibitins; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2; D015183:Restriction Mapping / Q000379:methods; D017422:Sequence Analysis, DNA; D051028:bcl-2-Associated X Protein
D020121:5' Untranslated Regions; C494826:BAX protein, human; D005819:Genetic Markers; C000717331:PHB2 protein, human; D000091402:Prohibitins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein