TNXA and hyperinsulinemic hypoglycemia, familial, 4: Tnxb deletion can even be caused by a contiguous deletion syndrome (CAH-X) [60], in which patients have a 21-hydroxylase deficiency causing congenital adrenal hyperplasia and hEDS in which tnxb exons are replaced by tnxa, giving birth to tnxa/tnxb chimeras [60,61,62].