The cause of sporadic LAM is at present unknown. We know that it is not inherited and it is not passed on to children. We also know that one of two proteins (called tuberin and hamartin) are abnormal in LAM tissue. This is due to a mutation in the genes responsible for these proteins. The proteins act as a brake on the growth of smooth muscle cells in the lung and when they are abnormal there is excessive growth of LAM cells. Why this should happen is not clear, however, but stopping the growth of these cells is the subject of research.(see Is research taking place?).
Juliet Stevenson