Improving the diagnosis of 11β-hydroxylase deficiency using home-made MLPA probes: identification of a novel chimeric CYP11B2/CYP11B1 gene in a Sicilian patient

Purpose 11β-Hydroxylase deficiency (11OHD) represents the second most common cause of congenital adrenal hyperplasia. It is caused by mutations in the CYP11B1 gene localized about 40 kb from the CYP11B2 gene with which it shares a homology of 95 %. The asymmetric recombination of these two genes is involved both in 11OHD and in glucocorticoid-remediable aldosteronism (GRA). Our objective was to set up an easy and rapid method to detect these hybrid genes and other kinds of deletions, to improve the molecular diagnosis of 11OHD.