spondylo-meta-epiphyseal dysplasia spondylo-meta-epiphyseal dysplasia spondylo-meta-epiphyseal dysplasia (smed) is a rare autosomal-recessive disease that causes skeletal disorders. smed is thought to be caused by a mutation in the discoidin domain receptor 2 (ddr2) gene. spondylo-meta-epiphyseal dysplasiathis condition is inherited in an autosomal recessive manner.