In the present study, PMs for the UGT1A1 gene were found in 11.0% of PC patients, with the UGT1A1*6/*28 genotype being the most prevalent (7.1%), followed by UGT1A1*6/*6 (3.2%) and UGT1A1*28/*28 (0.6%). This evidence concerns the gene UGT1A1 and pachyonychia congenita.