Mycosis fungoides is the most common form of a type of blood cancer called cutaneous T-cell lymphoma. Cutaneous T-cell lymphomas occur when certain white blood cells, called T cells, become cancerous; these cancers characteristically affect the skin, READ MORE

MyD88 deficiency is an inherited disorder of the immune system (primary immunodeficiency). This primary immunodeficiency affects the innate immune response, which is the body's early, nonspecific response to foreign invaders (pathogens). MyD88 defici READ MORE

MYH9 -related disorder is a condition that can have many signs and symptoms, including bleeding problems, hearing loss, kidney (renal) disease, and clouding of the lens of the eyes (cataracts). The bleeding problems in people with MYH9 -related disor READ MORE

Myhre syndrome is a rare condition that affects connective tissue. Connective tissue provides strength and flexibility to structures throughout the body. Myhre syndrome has a variety of signs and symptoms that affect many parts of the body, though no READ MORE

Myoclonic epilepsy myopathy sensory ataxia, commonly called MEMSA, is part of a group of conditions called the POLG -related disorders. The conditions in this group feature a range of similar signs and symptoms involving muscle-, nerve-, and brain-re READ MORE

Myoclonic epilepsy with ragged-red fibers (MERRF) is a disorder that affects many parts of the body, particularly the muscles and nervous system. In most cases, the signs and symptoms of this disorder appear during childhood or adolescence. The featu READ MORE

Myoclonus-dystonia is a movement disorder that typically affects the neck, torso, and arms. Individuals with this condition experience quick, involuntary muscle jerks or twitches (myoclonus). About half of individuals with myoclonus-dystonia develop READ MORE

Myofibrillar myopathy refers to a group of disorders that are characterized by muscle weakness (myopathy) that worsens over time. Myofibrillar myopathy primarily affects the skeletal muscles, which are the muscles that the body uses for movement. In READ MORE

Myopathy with deficiency of iron-sulfur cluster assembly enzyme is an inherited disorder that primarily affects muscles used for movement (skeletal muscles). This condition does not usually affect other types of muscle, such as the heart (cardiac) mu READ MORE

Myosin storage myopathy is a condition that affects muscle (myopathy). This disorder causes muscle weakness that can worsen slowly over time. The signs and symptoms of myosin storage myopathy often begin in childhood, although they can begin later. T READ MORE

Myostatin-related muscle hypertrophy is a rare condition characterized by reduced body fat and increased muscle size. Affected individuals have up to twice the usual amount of muscle mass in their bodies. They also tend to have increased muscle stren READ MORE

Myotonia congenita is a disorder that affects muscles used for movement (skeletal muscles). Beginning in childhood, people with this condition experience bouts of sustained muscle tensing (myotonia) that prevent muscles from relaxing normally. Althou READ MORE