People with a family history of chronic rheumatoid arthritis are times more likely to develop the disease than other people. four three seven ten

People with a family history of chronic rheumatoid arthritis are three times more likely to develop the disease than other people. Rheumatoid arthritis is a chronic inflammatory disorder, that affects primarily the joints but also other systems of the body. It is an autoimmune disorder and it is caused by the immune system mistakenly attacking specific tissues and organs of the human body. Although the cause of this disorder is still unclear, it has been shown that first-degree relatives of a person with rheumatoid arthritis are three times more likely to develop the disease than other people. 

He used pea plants to study the patterns of heredity.