PSACH results from mutations in the cartilage oligomeric matrix protein (COMP) gene, while SEDC is caused by mutations in the gene for type II procollagen (COL2A1).
Kniest dysplasia is caused by dominant collagen II (COL2A1) mutations: parental somatic mosaicism manifesting as Stickler phenotype and mild spondyloepiphyseal dysplasia.
Phenotype of the twin girls resembles spondyloepiphyseal dysplasia congenita Spranger-Wiedemann (SEDC-SW), but shortening of the stature is more severe and the cranioface is normal.
Our study extends the mutation spectrum of SEDC and confirms genotype-phenotype relationship between mutations at glycine in the triple helix of the alpha-1(II) chains of the COL2A1 and clinical findings of SEDC, which may be helpful in the genetic counseling of patients with SEDC.
Although type II collagen defects have been found in some families with SED congenita, the phenotype in our family showed discordant segregation with COL2A1 gene associated restriction fragment length polymorphisms (RFLPs), the markers for the structural locus of type II collagen.
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.
Most COL2A1 mutations occur in the triple helical region of alpha 1(II) chains: the SED spectrum is mostly attributed to missense mutations that substitute bulky amino acids for glycine residues, STD-I to haploinsufficiency of truncation mutations, and KND to exon skipping due to splice-site mutations.
Two human patients with spondyloepiphyseal dysplasia (SED) congenita have been reported with the same amino acid substitution at position 789 in the human COL2A1 gene.
Mutations in the COL2A1 gene have been identified in one family with spondyloepiphyseal dysplasia and secondary deposits of pyrophosphate and apatite crystalline deposits.
This study confirmed the importance of dominant negative mutations of the COL2A1 gene in producing the spondyloepiphyseal dysplasia congenita phenotype.
Our study contributed to the further expansion of the COL2A1 mutation spectrum and provided more information concerning SEDC in the Chinese population through literature review.
Arginine to cysteine mutations are rather infrequent COL2A1 mutations which cause a spectrum of phenotypes including classic SEDC and Stickler dysplasia, but also some unusual entities that have not yet been recognised and described as type II collagenopathies.
Mutation in the COL2A1 gene has been identified in one family with spondyloepiphyseal dysplasia and calcium pyrophosphate and apatite crystalline deposits.
Our study extends the mutation spectrum of SEDC and confirms genotype-phenotype relationship between mutations in the COL2A1 gene and clinical findings of SEDC.