PAPSS2 and spondyloepimetaphyseal dysplasia: Mutations in PAPSS2 cause an autosomal recessive form of spondyloepimetaphyseal dysplasia (SEMD), Pakistani type [OMIM:612847], in humans, whereas a point mutation in the adenosine 5'-phosphosulfate kinase region of Papss2 causes brachymorphism (bm) in mice [16-19].