Birt-Hogg-Dube Syndrome
An inherited syndrome affecting skin, lungs, and kidneys
Quick Facts
- Type: Inherited (genetic) syndrome
- Gene involved: FLCN gene
- Main features: Skin bumps, lung cysts, kidney tumors
- Inheritance: Autosomal dominant
Overview
Birt-Hogg-Dube syndrome is a rare genetic condition that affects three main organ systems: the skin, the lungs, and the kidneys. It is caused by changes (mutations) in a gene called FLCN, which normally helps control cell growth. People with the syndrome typically develop small benign skin bumps, cysts in the lungs that increase the risk of a collapsed lung, and tumors in the kidneys that can be benign or cancerous.
The condition is passed down in an autosomal dominant pattern, meaning a person needs only one altered copy of the gene to be affected, and each child of an affected parent has a 50 percent chance of inheriting it. Because of the kidney cancer risk, people diagnosed with Birt-Hogg-Dube are usually placed on a lifelong monitoring program.
Symptoms
Features often appear in adulthood and vary widely between individuals:
- Skin changes: Small, dome-shaped, flesh-colored or white bumps (fibrofolliculomas) on the face, neck, and upper trunk, usually appearing in the 20s to 40s
- Lung cysts: Often cause no symptoms but raise the risk of a collapsed lung (pneumothorax), which can bring sudden chest pain and shortness of breath
- Kidney tumors: Frequently silent in early stages; may cause blood in the urine, a mass, or flank pain if larger
Not everyone has all three features, and some people are diagnosed only after a relative is found to carry the gene.
Causes
Birt-Hogg-Dube syndrome is caused by a mutation in the FLCN gene, which provides instructions for a protein called folliculin. Folliculin acts as a tumor suppressor, helping keep cell growth in check.
- Inherited mutation: Most people inherit the altered gene from a parent.
- New mutation: Occasionally the gene change arises spontaneously with no family history.
When folliculin does not work properly, cells in the skin, lungs, and kidneys can grow abnormally, producing the characteristic features of the syndrome.
Risk Factors
- A parent or close relative with Birt-Hogg-Dube syndrome
- A family history of multiple skin bumps with collapsed lungs or kidney tumors
- A known FLCN gene mutation in the family
- Personal history of unexplained spontaneous pneumothorax at a younger age
Diagnosis
Diagnosis is based on the combination of features and confirmed with genetic testing:
- Skin examination and biopsy: To identify characteristic fibrofolliculomas.
- Chest imaging: A CT scan can detect lung cysts even when there are no breathing symptoms.
- Kidney imaging: MRI, CT, or ultrasound to look for kidney tumors.
- Genetic testing: A blood test to identify an FLCN mutation, which confirms the diagnosis and allows family members to be tested.
Treatment
There is no cure for the underlying gene change, so care focuses on managing each feature and watching for kidney cancer:
- Kidney monitoring: Regular imaging, often starting in early adulthood, to catch tumors while small; small tumors may be watched, and larger ones removed surgically with kidney-sparing techniques when possible.
- Lung care: Treating a collapsed lung if it occurs and avoiding activities or, in some cases, situations that raise pneumothorax risk; smoking cessation is strongly advised.
- Skin treatment: The skin bumps are harmless; laser or other cosmetic procedures may be used if desired, though bumps can recur.
Genetic counseling helps families understand inheritance and testing options.
Prevention
- The syndrome itself cannot be prevented because it is inherited
- Regular kidney imaging allows early detection and treatment of tumors
- Not smoking reduces lung cyst and pneumothorax risk
- Genetic counseling and testing help at-risk relatives plan monitoring
- Prompt attention to sudden chest pain or breathlessness can prevent complications
When to See a Doctor
See a doctor if you have multiple unexplained skin bumps along with a personal or family history of collapsed lung or kidney tumors. Seek emergency care right away for:
- Sudden, sharp chest pain
- Sudden shortness of breath
- These can signal a collapsed lung, which needs urgent treatment
Also tell your doctor about blood in the urine or a known family history so that appropriate monitoring can begin.
Frequently Asked Questions
Does Birt-Hogg-Dube syndrome always cause kidney cancer?
No. The syndrome raises the risk of kidney tumors, but not everyone develops them, and many tumors that do occur are slow-growing or benign. Regular imaging allows any tumors to be found early, when treatment is most effective.
Are the skin bumps in Birt-Hogg-Dube dangerous?
The characteristic skin bumps, called fibrofolliculomas, are benign and do not turn into cancer. They are mainly a cosmetic concern and an important clue that prompts evaluation for the lung and kidney features of the syndrome.
How is Birt-Hogg-Dube syndrome inherited?
It is passed down in an autosomal dominant pattern, so a single altered copy of the FLCN gene causes the condition. Each child of an affected person has a 50 percent chance of inheriting the gene change.
Why do people with this syndrome get collapsed lungs?
The syndrome causes cysts to form in the lungs. These cysts can rupture, allowing air to leak into the chest and the lung to collapse, which causes sudden chest pain and breathlessness and requires urgent care.
Should my family be tested if I have this condition?
Genetic counseling is recommended. Because the syndrome is inherited, first-degree relatives may carry the same gene change. Testing helps identify who needs kidney and lung monitoring even before symptoms appear.
References
- National Cancer Institute (NCI). Birt-Hogg-Dube Syndrome.
- Genetic and Rare Diseases Information Center (GARD). Birt-Hogg-Dube syndrome.
- MedlinePlus Genetics, U.S. National Library of Medicine. Birt-Hogg-Dube syndrome.
- National Organization for Rare Disorders (NORD). Birt-Hogg-Dube Syndrome.