As the extreme C-terminus of human HMGCR does not resemble a PTS1, we expected a PTS2 and tested this hypothesis by studying primary human fibroblasts from a patient suffering from type-1 rhizomelic chondrodysplasia punctata (RCDP1), in which the PTS2 receptor PEX7 is mutated. The gene discussed is PEX7; the disease is rhizomelic chondrodysplasia punctata type 1.