The independent and joint contributions of the maternal, child, and dyadic pathways following KC and their mutual influences over time were examined in relation to three outcomes in young adulthood: (a) psychological symptoms in terms of anxiety and depressive symptoms, (b) the oxytocin system, and (c) immune system functionality as measured by levels of secretory immunoglobulin A (s-IgA), a first line mucosal barrier that serves as an index for the immune system. The gene discussed is OXT; the disease is keratoconus.