TNXB and Ehlers-Danlos syndrome: Among the 14 types of EDS, non-collagenous classical-like EDS (clEDS) is the result of tenascin-X (TNX) deficiency with homozygous or compound heterozygous mutations in its gene (TNXB) (Burch et al., 1997; Schalkwijk et al., 2001; Malfait et al., 2017).