Dr. Lisa Young and Frank McCormack at the University of Cincinnati are conducting a study to develop a blood test that can be used to distinguish between BHD and another disorder that produces cysts in the lung called lymphangioleiomyomatosis. To qualify for the study, you must be a female with BHD, above the age of 18, and have known cystic changes in the lung. If you would like to participate, please contact firstname.lastname@example.org or call 513 558 4831. After signing an informed consent, you will be asked to have a tube of blood drawn by your local doctors office or clinical lab, and returned to us in a mailing kit that will be sent to you. You will also be asked to provide very limited clinical information, including age, smoking history, pneumothorax history, and spirometry results, if available.