PAPSS2 and brachyolmia: Furthermore, brachyolmia, which is characterized by a short stature, short trunk, irregular endplates, narrow intervertebral disks, precocious calcification of rib cartilages, a short femoral neck, mildly shortened metacarpals, and a normal intelligence and facies, are also caused by compound heterozygous and homozygous mutations in PAPSS2 (Table 5; Miyake et al., 2012; Iida et al., 2013; Bownass et al., 2019).