Some variants that cause autosomal-recessive congenital adrenal hyperplasia (CAH) also cause hypermobility type Ehlers-Danlos syndrome (EDS) due to the monoallelic presence of a chimera disrupting two flanking genes: CYP21A2, encoding 21-hydroxylase, necessary for cortisol and aldosterone biosynthesis, and TNXB, encoding tenascin-X, an extracellular matrix protein.