Forty-three subjects (4.36%) carried the HLA-B*35:05 allele, one subject and 42 subjects (4.26%) carry homozygous and heterozygous HLA-B*35:05 genotypes, respectively, Thirty subjects (3.04%) carry heterozygous HLA-B*57:01, which is known to be associated with abacavir-induced hypersensitivity syndrome (AHS). This evidence concerns the gene HLA-B and mitochondrial DNA depletion syndrome 4a.