"Histologic findings include rarefied cartilage matrix, loss of normal ground glass appearance of cartilage on HE staining, coarse collagen fibres and collagen rings."
"Achondrogenesis 1B is thought to carry an autosomal recessive inheritance. Point mutations and deletions of the diastrophic dysplasia sulphatase transporter (DTDST) gene it thought to be the underlying factor. This is located on chromosome 5q and is responsible for sulfate transport. The mutation results in impaired activity of the sulfate transporter in chondrocytes and fibroblasts and results in the synthesis of proteoglycans which are not sulfated or only insufficiently sulfated (probably by depletion of intracellular sulfate)."
"type Ib: Parenti-Fraccaro subtype"