CYP21A2 and congenital adrenal hyperplasia: The term CAH-X was coined to describe a subset of patients with congenital adrenal hyperplasia (CAH) who display the hypermobility phenotype of Ehlers–Danlos syndrome (hEDS) due to the monoallelic presence of a CYP21A2 deletion extending into the TNXB gene [1,2].