<h4>Background</h4>Defects in both <i>CYP21A2</i> and <i>TNXB</i> genes cause congenital adrenal hyperplasia combined with hypermobility-type Ehlers-Danlos syndrome (EDS), which has been named CAH-X syndrome.<h4>Objective</h4>This study aimed to determine the frequency of CAH-X within the Munich cohort of CAH patients (<i>n</i> = 155: salt wasting = 94, simple virilizing = 44, non-classical = 12, gene carrier = 4, 11β-deficiency = 1) and assess its clinical implications by thorough clinical characterization of the cohort. Here, CYP21A2 is linked to hyperinsulinemic hypoglycemia, familial, 4.