CCND1 Gene

Multiple myeloma is a cancer that develops in the bone marrow, the spongy tissue found in the center of most bones. The bone marrow produces red blood cells, which carry oxygen throughout the body; white blood cells, which form the body's defenses (immune system); and platelets, which are necessary for blood clotting.

Multiple myeloma is characterized by abnormalities in plasma cells, a type of white blood cell. These abnormal cells multiply out of control, increasing from about one percent of cells in the bone marrow to the majority of bone marrow cells. The abnormal cells form tumors within the bone, causing bone pain and an increased risk of fractures. If the tumors interfere with nerves near the bones, numbness or weakness in the arms or legs can occur. Affected individuals may also experience a loss of bone tissue, particularly in the skull, spine, ribs, and pelvis. The deterioration of bone can result in an excess of calcium in the blood (hypercalcemia), which can lead to nausea and loss of appetite, excessive thirst, fatigue, muscle weakness, and confusion.

The abnormal plasma cells in multiple myeloma produce proteins that impair the development of normal blood cells. As a result, affected individuals may have a reduced number of red blood cells (anemia), which can cause fatigue, weakness, and unusually pale skin (pallor); a low number of white blood cells (leukopenia), which can result in a weakened immune system and frequent infections such as pneumonia; and a reduced number of platelets (thrombocytopenia), which can lead to abnormal bleeding and bruising. Kidney problems can also occur in this disorder, caused by hypercalcemia or by toxic proteins produced by the abnormal plasma cells.

People with multiple myeloma typically develop the disorder around age 65. Over time, affected individuals can develop life-threatening complications, but the rate at which this happens varies widely. Some affected individuals are diagnosed incidentally when tests are done for other purposes and do not experience symptoms for years.

Von Hippel-Lindau syndrome is an inherited disorder characterized by the formation of tumors and fluid-filled sacs (cysts) in many different parts of the body. Tumors may be either noncancerous or cancerous and most frequently appear during young adulthood; however, the signs and symptoms of von Hippel-Lindau syndrome can occur throughout life.

Tumors called hemangioblastomas are characteristic of von Hippel-Lindau syndrome. These growths are made of newly formed blood vessels. Although they are typically noncancerous, they can cause serious or life-threatening complications. Hemangioblastomas that develop in the brain and spinal cord can cause headaches, vomiting, weakness, and a loss of muscle coordination (ataxia). Hemangioblastomas can also occur in the light-sensitive tissue that lines the back of the eye (the retina). These tumors, which are also called retinal angiomas, may cause vision loss.

People with von Hippel-Lindau syndrome commonly develop cysts in the kidneys, pancreas, and genital tract. They are also at an increased risk of developing a type of kidney cancer called clear cell renal cell carcinoma and a type of pancreatic cancer called a pancreatic neuroendocrine tumor.

Von Hippel-Lindau syndrome is associated with a type of tumor called a pheochromocytoma, which most commonly occurs in the adrenal glands (small hormone-producing glands located on top of each kidney). Pheochromocytomas are usually noncancerous. They may cause no symptoms, but in some cases they are associated with headaches, panic attacks, excess sweating, or dangerously high blood pressure that may not respond to medication. Pheochromocytomas are particularly dangerous in times of stress or trauma, such as when undergoing surgery or in an accident, or during pregnancy.

About 10 percent of people with von Hippel-Lindau syndrome develop endolymphatic sac tumors, which are noncancerous tumors in the inner ear. These growths can cause hearing loss in one or both ears, as well as ringing in the ears (tinnitus) and problems with balance. Without treatment, these tumors can cause sudden profound deafness.

Noncancerous tumors may also develop in the liver and lungs in people with von Hippel-Lindau syndrome. These tumors do not appear to cause any signs or symptoms.