Context: Family history is a risk factor for asthma, with many different genes being implicated. If one identical twin is affected, the probability of the other having the disease is approximately 25%. By the end of 2005, 25 genes had been associated with asthma in six or more separate populations, including GSTM1, IL10, CTLA-4, SPINK5, LTC4S, IL4R and ADAM33, among others. Many of these genes are related to the immune system or modulating inflammation. Even among this list of genes supported by highly replicated studies, results have not been consistent among all populations tested. In 2006 over 100 genes were associated with asthma in one genetic association study alone; more continue to be found.

Question: What else is a risk factor for asthma?
Answer: Family history

Question: If one identical twin has asthma, what are the odds of the other twin having asthma?
Answer: approximately 25%

Question: How many genes were associated with asthma by the end of 2005?
Answer: 25 genes

Question: What else are these genes closely related to?
Answer: the immune system or modulating inflammation

Question: How many genes were associated with asthma in 2006?
Answer: over 100 genes

Question: What is a risk factor for modulating inflammation?
Answer: Unanswerable

Question: What is thought to be the cause of modulating inflammation?
Answer: Unanswerable

Question: In 2006 what percentage of genes were found to contribute to inflammation?
Answer: Unanswerable

Question: How many genes were associated with the immune system in 2006?
Answer: Unanswerable

Question: How many genes were associated with causing GSTM1 in 2005?
Answer: Unanswerable