Intronic variants in BRCA1 and BRCA2 that affect RNA splicing can be reliably selected by splice-site prediction programs
✍ Scribed by Maaike P.G. Vreeswijk; Jaennelle N. Kraan; Heleen M. van der Klift; Geraldine R. Vink; Cees J. Cornelisse; Juul T. Wijnen; Egbert Bakker; Christi J. van Asperen; Peter Devilee
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 402 KB
- Volume
- 30
- Category
- Article
- ISSN
- 1059-7794
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✦ Synopsis
A large number of sequence variants identified in BRCA1 and BRCA2 cannot be distinguished as either disease-causing mutations or neutral variants. These so-called unclassified variants (UVs) include variants that are located in the intronic sequences of BRCA1 and BRCA2. The purpose of this study was to assess the use of splice-site prediction programs (SSPPs) to select intronic variants in BRCA1 and BRCA2 that are likely to affect RNA splicing. We performed in vitro molecular characterization of RNA of six intronic variants in BRCA1 and BRCA2. In four cases (BRCA1, c.81-6T4A and c.498615G4T; BRCA2, c.76171 2T4G and c.875415G4A) a deleterious effect on RNA splicing was seen, whereas the c.135-15_-12del variant in BRCA1 showed no effect on RNA splicing. In the case of the BRCA2 c.68-7T4A variant, RNA analysis was not sufficient to establish the clinical significance. Six SSPPs were used to predict whether an effect on RNA splicing was expected for these six variants as well as for 23 intronic variants in BRCA1 for which the effect on RNA splicing has been published. Out of a total of 174 predictions, 161 (93%) were informative (i.e., the wild-type splice-site was recognized). No falsenegative predictions were observed; an effect on RNA splicing was always predicted by these programs. In four cases (2.5%) a false-positive prediction was observed. For DNA diagnostic laboratories, these programs are therefore very useful to select intronic variants that are likely to affect RNA splicing for further analysis.