GJB2 and Hodgkins lymphoma: Among Europeans, the most common pathogenic mutation in the GJB2 gene is a deletion of guanine at position 35 (NM_004004.5:c.35delG).9, 10 In most cases (70%), HL occurs as an isolated defect; in other instances it is accompanied by heart, craniofacial, kidney, skin, and other defects.