It is generated by intrachromosomal recombination between a sequence (1 Kb) in intron 1 (int1h1) and a homologous sequence (inth1h2) separated by 140 Kb in the 5’ direction [48,51] in the telomere, resulting in a split FVIII gene, with the promoter and exon 1 separated from the remaining gene, resulting in severe haemophilia A [51]. This evidence concerns the gene F8 and hemophilia A.