A prevalent mutation with founder effect in Spanish Recessive Dystrophic Epidermolysis Bullosa families

BACKGROUND: Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a genodermatosis caused by more than 500 different mutations in the COL7A1 gene and characterized by blistering of the skin following a minimal friction or mechanical trauma. The identification of a cluster of RDEB pedigrees carrying the c.6527insC mutation in a specific area raises the question of the origin of this mutation from a common ancestor or as a result of a hotspot mutation. The aim of this study was to investigate the origin of the c.6527insC mutation. METHODS: Haplotypes were constructed by genotyping nine single nucleotides polymorphisms (SNPs) throughout the COL7A1 gene. Haplotypes were determined in RDEB patients and control samples, both of Spanish origin. RESULTS: Sixteen different haplotypes were identified in our study. A single haplotype cosegregated with the c.6527insC mutation. CONCLUSION: Haplotype analysis showed that all alleles carrying the c.6527insC mutation shared the same haplotype cosegregating with this mutation (CCGCTCAAA_6527insC), thus suggesting the presence of a common ancestor.