LAM: Causes Make an Appointment Refer a Patient Ask a Question Reviewed by Gregory Downey, MD, Gregory P. Downey, MD (February 02, 2023) There are different causes for the two types of Lymphangioleiomyomatosis (LAM). Sporadic LAM Changes to the TSC1 and the TSC2 genes cause sporadic LAM. These genes make proteins that suppress tumors and make sure cells grow at the right speed and to the right size. When these genes are mutated, the proteins can’t control cell growth which results in tumors and cysts. Hormones such as estrogen are suspected to play a role in sporadic LAM, but more research is needed on this topic. Tuberous sclerosis LAM An inherited syndrome called tuberous sclerosis complex, causes LAM to occur as well as numerous noncancerous tumors to grow in the skin, brain, kidneys and other organs. It also and causes developmental problems and seizures. LAM: Symptoms Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.