Gene deletion

Our laboratory has successfully used SYBR® Green detection method to diagnose gene deletions. Point mutations and small insertions or deletions in the OPA1 gene have been shown to underlie more than half of all cases

1000 i

ld ol mi mi

PBMC 4699 4801 4813 4818 4695 4334 4819 4306 4777

MYCN

PBMC 4699 4801 4813 4818 4695 4334 4819 4306 4777

MYCN

Figure 8.6

MCYN gene amplification in neuroblastoma tumors. We applied a SYBR® Green 1 gene amplification assay to tumor samples for the detection of MYCN. These samples had been tested previously by standard procedures for the diagnosis of neuroblastoma using FISH (De Preter et al., 2002). Our results (black bars) compared well with the established amplification factor recorded for these tumors (grey bars) and confirmed the presence of MYCN amplification (Ponchel et al., 2003).

of dominant optic atrophy. In addition, two larger deletions in OPA1 have been detected, each in a single family. One of these deletes exon 20 and the surrounding intronic DNA (Alexander et al., 2000), while the other deletes the entire gene and over half a megabase of surrounding DNA (Marchbank et al., 2002). We designed a SYBR® Green I assay to quantify the number of copies of OPA1 exon 20 present in any given sample, which should therefore detect both of these deletions. We tested this on genomic DNA from patients and healthy members of the family and were able to confirm a reduction in relative copy number in these patients with the deletion of the entire gene, compared to healthy members of the family (Ponchel et al., 2003).

Was this article helpful?

0 0

Post a comment