Furthermore, variants in COL3A1, such as the p.Gly637Ser mutation, have been linked to collagen synthesis abnormalities in a single family with the autosomal dominant hEDS phenotype that was identified which led to reduced collagen secretion and the over-modification of collagen [5,73]. This evidence concerns the gene COL3A1 and Ehlers-Danlos syndrome, hypermobility type.