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. This evidence concerns the gene GNAS and hypoparathyroidism.