CFTR and cystic fibrosis: All patients with ADGRG2 mutations (Fig. 1) displayed CBAVD only, and no other symptoms of CF (as with certain mild CFTR variants) - indicating a possible similar involvement of both genes in the development of CBAVD [98, 99] In a recent study, an additive nonsense ADGRG2 mutation was described in two brothers with OA from a Pakistani family [104], confirming the involvement of ADGRG2 mutations in OA.