Birt-Hogg-Dubé Syndrome (BHD), also known as Hornstein-Knickenberg syndrome, is a rare genetic disorder that affects the skin, lungs, and kidneys. Symptoms of BHD can be different between affected people, even within the same family, and typically present when an affected person is in their 20s or 30s. The symptoms may include non-cancerous (benign) skin growths (tumors) on the face, neck, ears, or chest. BHD can also cause too much air to be trapped in the chest (pneumothorax), which can cause a collapsed lung. Some people may also develop cancerous or non-cancerous tumors in the kidney.
BHD is caused by a mutation (change) in the FLCN gene and is inherited in an autosomal dominant manner. This means that a person only needs a mutation in one of their two FLCN gene copies to cause BHD. Most of the time, an affected person inherits the mutation from a parent.
The diagnosis is suspected in people who develop the skin tumors or have repeated lung collapses. Diagnosis of BHD can only be confirmed by genetic testing of the FLCN gene. Although BHD does not have a cure, most cases can be managed and are not life threatening. Skin lesions can be removed or treated by skin doctors (dermatologists). Other symptoms, such as kidney tumors and pneumothoraces, should be screened for regularly in affected individuals. If you have been diagnosed with BHD, talk with your doctor about current treatment recommendations. Support groups are a great resource for support and additional information.