Rheumatoid arthritis . Familial or hereditary amyloidosis is the only inherited form of the disease. It occurs in members of most ethnic groups, and each family has a distinctive pattern of symptoms and organ involvement. Hereditary amyloidosis is though to be autosomal dominant, which means that only one copy of the defective gene is necessary to cause the disease. A child of a parent with familial amyloidosis has a 50-50 chance of developing the disease.
Amyloidosis can involve any organ or system in the body.
The heart, kidneys, gastrointestinal system, and nervous system are affected most often. Other common sites of amyloid accumulation include the brain, joints, liver, spleen, pancreas, respiratory system, and skin. The cause of amyloidosis is unknown. Usually the affected organs are rubbery, firm, and enlarged. Because amyloid protein deposits can limit the heart's ability to fill with blood between beats, even the slightest exertion can cause shortness of breath .