The brachymorphic mouse, with spontaneous mutation in phosphoadenosine phosphosulfate (PAPS) synthase 2, which synthesizes the sulfate donor PAPS for GAG sulfation, showed postnatal chondrodysplasia, reduction in sulfation level on CS in cartilage, and abnormal Indian hedgehog (Ihh) distribution in cartilage ECM [38]. Here, IHH is linked to chondrodysplasia.