Melorheostosis: A rare bone condition that usually begins in childhood characterized by thickening of the bones (sclerosis) of a limb. Pain is frequent in the involved limb. The affected bone can have the appearance of "dripping candle wax" when visualized with X-ray imaging.
Membranoproliferative glomerulonephritis (GN) type II is a kidney disorder causing decreased kidney function because of inflammation and changes in the tissues of the internal kidney structures.
A disease of the glomerulus manifested clinically by proteinuria, and sometimes by other features of the nephrotic syndrome. It is histologically characterized by deposits in the glomerular capillary wall between the epithelial cell and the basement membrane and a thickening of the membrane. Also characteristic are outward projections of the membrane between the epithelial deposits in the form of "spikes". There is some agreement that the deposits are antigen-antibody complexes.
Myoclonic epilepsy myopathy sensory ataxia (MEMSA) is a disease which starts in childhood to late adulthood. The symptoms include problems in movement coordination, seizures and uncontrollable muscle jerks as well as a degeneration of muscles and brain dysfunctions. The disease itself is caused by a mutation in the DNA of mitochondria, which leads to a lower energy supply in the cells of the body. Treatment of MEMSA is largely supportive, including physiotherapy, speech therapy and seizure management.
Other names: Spinocerebellar ataxia with epilepsy (SCAE)
Sources: Genetics Home Reference (NIH), GeneReviews
Mendelian susceptibility to atypical mycobacteria: A very rare group of disorders where a person without an immune deficiency is susceptible to infection by weak mycobacterial organisms, nontuberculous and environmental mycobacteria e.g. Calmette-Guerin Bacillus (BCG). The severity of the disorder is greatly variable and ranges from a localized recurring non-tuberculous mycobacterial infection to a potentially fatal BCG infection. Most people who are infected with these organisms have no symptoms but a genetic mutation in some people makes them more susceptible.
Ménétrier disease causes the ridges along the inside of the stomach wall—called rugae—to enlarge, forming giant folds in the lining of the stomach. The rugae enlarge because of an overgrowth of surface mucous cells of the stomach. In a normal stomach, rugae release protein-containing mucus. Enlarged rugae release too much mucus, causing a leakage of protein from the blood into the stomach. This shortage of protein in the blood is known as hypoproteinemia. Ménétrier disease also causes a decrease in stomach acid resulting from a reduction in acid-producing parietal cells.
Mengel Konigsmark syndrome (medical condition): A rare disorder characterized by hearing loss and external ear malformations.
Ménière's disease , is a disorder of the inner ear that can affect hearing and balance. It is characterized by episodes of vertigo, tinnitus, and hearing loss. The hearing loss comes and goes for some time, alternating between ears, then becomes permanent.
The condition is named after the French physician Prosper Ménière, who, in an 1861 article, first reported that vertigo was caused by inner ear disorders. The condition affects people differently; it can range in intensity from being a mild annoyance to a lifelong condition.
Meningeal angiomatosis - cleft hypoplastic left heart: A very rare genetic disorder characterized by an underdeveloped left heart and abnormal brain development.
A slow-growing tumor of the meninges that is not cancerous. Symptoms are determined by the size and location of the tumor.
Meningocele is a type of spina bifida in which the spinal cord develops normally but the meninges protrude from a spinal opening. Symptoms vary; while some people will have few or no symptoms of spina bifida, other people may have incomplete paralysis with urinary and bowel dysfunction.
Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis (also termed meningococcus). It carries a high mortality rate if untreated but is a vaccine-preventable disease. While best known as a cause of meningitis, widespread blood infection can result in sepsis, which is a more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries.
There are approximately 2,600 cases of bacterial meningitis per year in the United States, and on average 333,000 cases in developing countries. The case fatality rate ranges between 10 and 20 percent. The incidence of endemic meningococcal disease during the last 13 years ranges from 1 to 5 per 100,000 in developed countries, and from 10 to 25 per 100,000 in developing countries. During epidemics the incidence of meningococcal disease approaches 100 per 100,000.Meningococcal vaccines have sharply reduced the incidence of the disease in developed countries.
The disease's pathogenesis is not fully understood. The pathogen colonises a large number of the general population harmlessly, but in some very small percentage of individuals it can invade the blood stream, and the entire body but notably limbs and brain, causing serious illness. Over the past few years, experts have made an intensive effort to understand specific aspects of meningococcal biology and host interactions, however the development of improved treatments and effective vaccines is expected to depend on novel efforts by workers in many different fields.
While meningococcal disease is not as contagious as the common cold (which is spread through casual contact), it can be transmitted through saliva and occasionally through close, prolonged general contact with an infected person.
Meningococcemia is an acute and potentially life-threatening infection of the bloodstream that commonly leads to vasculitis (inflammation of the blood vessels).
Meningoencephalocele: A very rare developmental disorder where a part of the membrane that covers the brain and or part of the brain itself protrudes through an abnormal opening in the skull. The condition may be asymptomatic or if the defect is large, severe neurological abnormalities may result.
Meningoencephalocele - arthrogryposis - hypoplastic thumb: A rare disorder characterized by the association of joint contractures, meningoencephalocele and underdeveloped thumb.
Meningomyelocele: A very rare developmental disorder where a part of the membrane that covers the spinal cord and part of the spinal cord itself protrudes through an abnormal opening in the bones of the spinal column. The condition may be asymptomatic or if the defect is large, severe neurological abnormalities may result.
Menkes syndrome (MNK, Menkes disease, copper transport disease, steely hair disease, kinky hair disease, Menkes kinky hair syndrome), is a disorder that affects copper levels in the body, leading to copper deficiency. It is an x-linked recessive disorder, and is therefore considerably more common in males: females require two defective alleles to develop the disease.
The disorder was originally described by John Hans Menkes (1928–2008) et al. in 1962.
Mental mixed retardation - deafness - clubbed digits: A rare disorder characterized mainly by mental retardation, deafness and clubbed fingers.
Mental retardation - anophthalmia - craniosynostosis: A very rare syndrome characterized mainly by mental retardation, absent eyes and premature fusion of skull bones.
Mental retardation - arachnodactyly - hypotonia - telangiectasia: A very rare syndrome characterized mainly by mental retardation, short fingers, reduced muscle tone and spider veins (telangiectasia).
A mental condition that is characterised by a significantly low IQ.
Mental retardation - blepharophimosis - obesity - web neck: A very rare syndrome characterized mainly by mental retardation, eye abnormalities, obesity and a webbed neck
Mental retardation, Buenos Aires type: A very rare syndrome characterized mainly by mental retardation, physical retardation, unusual facial appearance and heart and kidney defects.
Mental retardation - coloboma - slimness: A very rare syndrome characterized mainly by mental retardation, retinal coloboma and a slim build.
Mental retardation - contractural arachnodactyly: A rare disorder characterized mainly by the association of mental retardation with long thin fingers which were permanently flexed.
Mental retardation - dysmorphism - hypogonadism - diabetes: A very rare syndrome characterized mainly by mental retardation, hypogonadism, diabetes and facial and skull abnormalities.
A very rare syndrome characterized mainly by mental retardation, epilepsy and a bulbous nose. The condition has been reported in only two families.
Mental retardation - epilepsy - bulbous nose: A very rare syndrome characterized mainly by mental retardation, epilepsy and a bulbous nose. The condition has been reported in only two families.