In the last decade, biology and medicine have undergone a fundamental change: next generation sequencing (NGS) technologies have enabled to obtain genomic sequences very quickly and at small costs compared to the traditional Sanger method. These NGS technologies have thus permitted to collect genomic sequences (genes, exomes or even full genomes) of individuals of the same species. These latter sequences are identical to more than 99%. There is thus a strong need for efficient algorithms for indexing and performing fast pattern matching in such specific sets of sequences. In this paper we propose a very efficient algorithm that solves the exact pattern matching problem in a set of highly similar DNA sequences where only the pattern can be pre-processed. This new algorithm extends variants of the Boyer-Moore exact string matching algorithm. Experimental results show that it exhibits the best performances in practice.