Several psoriasis susceptibility loci have been mapped (6p21.3, 17q, 4q, 1cen-q21, 3q21, 19p, 16q and 20p).15 In turn, GaSprotein is encoded by a gene (GNAS1) located in chromosome 20q13.1-13.2.12 Thus, the possibility that the association between psoriasis and hypoparathyroidism is related to other mutations not yet characterized for these diseases cannot be excluded. Here, GNAS is linked to psoriasis.