Pathogenic sequence variants in the solute carrier family 26 member 2 (SLC26A2) gene result in lethal (achondrogenesis Ib and atelosteogenesis II) and non-lethal (diastrophic dysplasia and recessive multiple epiphyseal dysplasia, rMED) chondrodysplasias.
Mutations in these genes cause a plethora of diseases such as diastrophic dysplasia affecting sulfate uptake into chondrocytes (SLC26A2), congenital chloride-losing diarrhoea (SLC26A3) affecting chloride secretion in the intestine and Pendred's syndrome (SLC26A4) resulting in hearing loss.
DTD is overrepresented in Finland and we speculated that this may have influenced the prevalence and spectrum of SLC26A2-related skeletal conditions also in Sweden.
Using mesenchymal stem cells (MSCs) in an in vitro chondrogenesis assay, we found that knockdown of the diastrophic dysplasia (DTD) sulfate transporter (DTDST, also known as SLC26A2), which is required for normal cartilage development, blocked cell condensation and caused a significant reduction in fibronectin matrix.
Importantly, mutations in SLC26A2, A3, A4, and A5 have been associated with distinct human genetic recessive disorders (i.e. diastrophic dysplasia, congenital chloride diarrhea, Pendred syndrome and deafness, respectively), demonstrating their essential and non-redundant functions in many tissues.
These findings reveal multiple roles for Slc26a2 in chondrocyte biology and emphasize the importance of Slc26a2-mediated protein sulfation in cell signaling, which may account for the complex phenotype of DTD.
This phenotype was intermediate between DTD and rMED, and both girls have a compound heterozygous mutations for the SLC26A2, a Finnish founder mutation (c.-26 + 2T>C), and R279W.
Pseudoachondroplasia and multiple epiphyseal dysplasia: a 7-year comprehensive analysis of the known disease genes identify novel and recurrent mutations and provides an accurate assessment of their relative contribution.
Mutations in the sulfate transporter gene, SCL26A2, lead to cartilage proteoglycan undersulfation resulting in chondrodysplasia in humans; the phenotype is mirrored in the diastrophic dysplasia (dtd) mouse.
Recessive multiple epiphyseal dysplasia (rMED) with homozygosity for C653S mutation in the DTDST gene--phenotype, molecular diagnosis and surgical treatment of habitual dislocation of multilayered patella: case report.
Recessive multiple epiphyseal dysplasia (rMED) with homozygosity for C653S mutation in the DTDST gene--phenotype, molecular diagnosis and surgical treatment of habitual dislocation of multilayered patella: case report.