The power of point mutations

Studies of human diseases have shown that nonsense mutations can alter pre-mRNA splicing. A new study, focusing on the breast cancer susceptibility gene, BRCA1, demonstrates that one explanation lies in a disrupted exonic splicing enhancer rather than a disrupted translational reading frame. Despite the growing appreciation of the frequent occurrence of exonic sequences that affect the use of splice sites, the prevalence of single-nucleotide polymorphisms that alter splicing has probably been vastly underestimated.