The BRIP1 gene may be a target of germline cancer-inducing mutations and has been shown to be mutated in FA-J (FANCJ) cells (Levran, O. et al., 2005, Nat Genet.). The protein encoded by the BRIP1 gene is a member of the RecQ DEAH helicase family that interacts with the BRCT repeats of breast cancer type 1 susceptibility protein (BRCA1). The bound complex is important in normal double-strand break repair function of BRCA1.
CHEK1 plays an essential role in the mammalian DNA damage checkpoint (G2/M DNA damage checkpoint), embryonic development, tumour suppression and is regulated by ATR (Liu, Q. et al., 2000, Genes Dev.).
The BRIP1 gene (20 exons) spans ~184.4 kb of genomic DNA and is located on chromosome 17q23.2, ~61.7 Mb from the p-telomere. The CHEK1 gene (14 exons) spans ~51.1 kb of genomic DNA and is located on chromosome 11q24.2, ~125.6 Mb from the p-telomere.
The P240-A3 BRIP1-CHEK1 probemix contains probes for each of the 20 exons of the BRIP1 gene and probes for 13 of the 14 exons of CHEK1. In addition, 12 reference probes are included in this probemix, detecting several different autosomal chromosomal locations.
This SALSA® MLPA® probemix is designed to detect deletions/duplications of one or more sequences in the aforementioned genes in a DNA sample. Heterozygous deletions of recognition sequences should give a 35-50% reduced relative peak height of the amplification product of that probe. Note that a mutation or polymorphism in the sequence detected by a probe can also cause a reduction in relative peak height, even when not located exactly on the ligation site! In addition, some probe signals are more sensitive to sample purity and small changes in experimental conditions. Therefore, deletions and duplications detected by MLPA should always be confirmed by other methods. Not all deletions and duplications detected by MLPA will be pathogenic; users should always verify the latest scientific literature when interpreting their findings. We have no information on what percentage of defects in these genes is caused by deletions/duplications of complete exons. Finally, note that most defects in these genes are expected to be small (point) mutations which will not be detected by this SALSA® MLPA® test.