Category: M

Mixed connective tissue disorder (MCTD) is one of many rheumatic diseases. Although it shares some similarities with lupus erythematosus and systemic sclerosis, MCTD differs in regard to the autoimmune factors (IgG autoantibodies) implicated (Maddison, 2000). Age of onset ranges from 5 to 80 years. Juvenile MCTD is rare; early identification and treatment can improve the…

Miller-Dieker syndrome (MDS) is a congenital, genetic disorder of brain development. Associated anomalies involve the face, genitalia, extremities, heart, and kidney.  

Mikulicz disease is one of the autoimmune disorders with Sjogren syndrome and systemic lupus erythematosis. With Mikulicz disease there is chronic bilateral enlargement of glands in the neck area (e.g., lacrimal, parotid, and salivary glands) similar to what might be expected with the mumps. Other glands in the area of face and neck may be…

Metaphyseal dysplasia, McKusick type (MDMT), is an uncommon genetic disorder of bone and cartilage formation (osteochondrodysplasia). Associated findings include short stature, abnormalities of hair, and a variety of immunologic and hematologic (blood cell) defects. MDMT is heritable, and its etiology has been traced to a defective gene on Chromosome 9.  

MERRF syndrome belongs to a group of neuromuscular disorders called mitochondrial myopathies. These disorders stem from a mitochondrial dysfunction that cause damage to muscles and nerve cells in the brain by impairing energy metabolism. Characteristic of MERRF syndrome are mitochondrial function and abnormal mitochondrial morphology resulting in ragged red fibers that can be seen in…

Mental retardation is defined as a disorder in which the overall intellectual functioning of a person is well below average, he or she has a significantly impaired ability to cope with common life demands, and he or she lacks the daily living skills required of others within their same age group. Mental retardation is a…

Menkes syndrome is inherited as an X-linked recessive disorder. It primarily affects males. It is characterized by severe mental degeneration, kinked or twisted brittle hair, skeletal changes, and the body’s inability to absorb copper.  

Memory processes are thought to be inseparable from other cognitive or learning processes, but memory is often conceptualized as the ability to encode, store, and retrieve information. Disorders of memory are often referred to as amnesia and typically involve impairment in the ability to learn new information or to recall previously learned information or events.…

Melkersson-Rosenthal syndrome (MRS) is a disease that generally begins late in childhood and is characterized by swelling of facial features, most frequently the lips. The areas of swelling may include the eyelids. MRS is most likely to become evident in childhood or adolescence. The swelling and facial palsy are believed to be due to lymphatic…

Meige syndrome or blepharospasm-oromandibular dystonia is a syndrome that is characterized by dyskinesia or the impairment of voluntary movement of muscles of the eye-lids and lower jaw. Movement is impaired such that there may be fragmentary or incomplete movements as well as uncontrolled or involuntary movements. With Meige syndrome, the muscles of the face and…