In view of the significant overlap among the different EDS subtypes, a definite diagnosis of cEDS is established by the identification on molecular genetic testing of a heterozygous pathogenic variant in COL5A1 (MIM *120215) and COL5A2 (MIM *120190) encoding type V collagen or, less commonly, in COL1A1, encoding type I collagen (Brady et al., 2017; Malfait et al., 2017). This evidence concerns the gene COL1A1 and Ehlers-Danlos syndrome.