One of the most common questions my patients ask me is whether their children are at risk for developing Idiopathic Pulmonary Fibrosis – whether it’s hereditary. The vast majority of patients have sporadic IPF (no risk of passing the disease to their children).
There are a few genes that have been found to be associated with familial IPF. Evaluating families with multiple affected family members identified these abnormal genes. Based on the available data, most familial cases are inherited as autosomal dominant—this means that there is a 50% chance of inheriting the abnormal gene that may causes the disease. Only a single abnormal copy of the gene is enough to develop the disease.
Patients without a family history of IPF can have mutations in the same genes that are associated with familial disease. This occurs through somatic mutations—mutations that develop after conception. These types of mutations are not passed on to your children.
It is critical to emphasize that the genetics of IPF are poorly understood and scientists are just beginning to make real progress. Below are some of the candidate genes that have been identified.
- Surfactant Genes
- In health, these proteins are critical to normal lung function providing lubrication and allow normal lung inflation.
- Telomerase Genes
- In health, these genes coordinate the repair of damage to the genetic information of cells.
- Mucin Genes
- In health, mucin is produced by lung tissue and helps with lubrication and may be involved in cell-cell signaling and preventing infection
Who should worry about familial Idiopathic Pulmonary Fibrosis?
If you have IPF and have a first-degree relative with Idiopathic Pulmonary Fibrosis, then you are at dramatically increased risk for having familial disease that you could pass to your children.
If I have familial IPF do I have a different prognosis?
A large study of patients and family members with familial IPF compared their age of onset, pulmonary function tests, imaging studies and survival to non-familial IPF. No differences were found. This was still a small retrospective (looking backwards in time) study. As we gather more information about familial and non-familial IPF we will be better able to answer this question.