mental deficiency

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Related to mental deficiency: mental retardation, Mentally handicapped

men·tal re·tar·da·tion

subaverage general intellectual functioning that originates during the developmental period and is associated with impairment in adaptive behavior. The American Association on Mental Deficiency lists eight medical classifications and five psychological classifications; the latter five replace the three former classifications of moron, imbecile, and idiot. Mental retardation classification requires assignment of an index for performance relative to a person's peers on two interrelated criteria: measured intelligence (IQ) and overall socioadaptive behavior (a judgmental rating of the person's relative level of performance in school, at work, at home, and in the community). In general an IQ of 70 or less indicates mental retardation (mild = 50/55-70; moderate = 35/40-50/55; severe = 20/25-35/40; profound = below 20/25); an IQ of 70-85 signifies borderline intellectual functioning.
Farlex Partner Medical Dictionary © Farlex 2012


(di-fish'en-se) [L. deficere, to lack]
Less than the normal amount; a lack.

acid lipase deficiency

One of two autosomal recessive illnesses in which the body lacks an enzyme for metabolizing fats, causing cholesterol, oils, or waxes to accumulate in abnormal amounts in the body. The acid lipase diseases are Wolman disease and cholesterol ester storage disease. Synonym: acid lipase disease
Acid lipase disease.

antithrombin-III deficiency

An inherited hypercoagulable state. It is due to absent or deficient levels of antithrombin III in the blood.
Synonym: hereditary thrombophilia

aspartoacylase deficiency

Canavan disease.

biotinidase deficiency

An autosomal recessive disease in which affected children fail to metabolize biotin effectively. Seizures, encephalopathy, neurodevelopmental delay, spasticity or diminished muscle tone, paresis, visual disturbances, deafness, skin rash, and hair loss commonly occur. Immediate ongoing treatment with supplemental biotin can effectively suppress the symptoms of this disease.

branching enzyme deficiency

Type IV glycogen storage disease.

ceramidase deficiency

Farber disease.

color deficiency

See: color blindness

color vision deficiency

See: color blindness

copper deficiency

The clinical consequences of inadequate consumption or absorption of dietary copper. Its hallmarks include an unsteady gait, neuropathy, muscle spasticity, and, occasionally, anemia. It may occur as a consequence of gastric bypass surgery or long-term parenteral nutrition.

delta storage pool deficiency

Dense granule deficiency syndrome.

functional iron deficiency

A deficiency of iron significant enough to affect the development of healthy red blood cells. It may precede the appearance of measurable anemia.

Patient care

Functional iron deficiency may be defined by the presence of hypochromatic red cells; by an increase in hemoglobin production after test doses of administered iron; or, most accurately, by the measurement of the mean hemoglobin content of reticulocytes. It is common in patients receiving hemodialysis and in critically ill persons.


Treatments include iron and folate supplements and epoetin alpha (Procrit) to increase red blood cell production. In emergencies, infusion of fresh frozen packed cells or washed packed cells provide temporary relief.

glucose-6-phosphate dehydrogenase deficiency

An X-linked disorder affecting the red blood cells. It is present in the U.S. in about 13% of black males and 2% of black females. The deficiency also occurs in Arab, Mediterranean, and Asian populations. The enzyme is essential to maintaining the integrity of erythrocytes; thus a deficiency of it causes nonimmune hemolytic anemia. There are many variants of the enzyme and great variation in severity of the disease. Some people do not have clinical symptoms until they are exposed to certain drugs (such as antimalarials, antipyretics, sulfonamides) or to fava beans, or when they contract an infectious disease. In others the condition is present at birth. When present at birth, anemia, hepatomegaly, hypoglycemia, and interference with growth are present. In those who have the deficiency but are not affected until exposed to certain drugs or infections, hemolytic anemia and jaundice occur.


Laboratory tests for evidence of the enzyme deficiency are available.


The only treatment is avoidance of drugs known to cause hemolysis and avoidance of fava beans if the person is known to be sensitive to them.

immune deficiency


intrinsic sphincter deficiency

Abbreviation: ISD
Weakening of the urethral sphincter muscles, a frequent cause of stress urinary incontinence.

leukocyte adhesion deficiency

Abbreviation: LAD
A rare autosomal recessive disorder in which white blood cells are unable to migrate out of blood vessels in response to infection. It often presents in early childhood with severe periodontal disease, premature loss of teeth, and recurrent infections.

medium-chain acyl-CoA dehydrogenase deficiency

Abbreviation: MCADD
An inherited disorder of faulty nutrient oxidation in which affected infants are unable to metabolize fatty acids when their stores of blood glucose are low, e.g., between meals. The disease is common, occurring in 1 in 10,000 infants, and often fatal in infancy. Surviving infants may suffer brain damage from inadequate nutrition to the central nervous system during fasts.

mental deficiency

See: mental retardation

muscle phosphorylase deficiency

McArdle disease

ornithine transcarbamylase deficiency

The most common urea cycle enzyme deficiency disorder inherited as an autosomal recessive trait, characterized by the absence of ornithine transcarbamylase (an enzyme in the urea cycle), which results in the excessive buildup of ammonia in the bloodstream. The disease is typically diagnosed in infancy and occurs in less than 1 in 8000 births.

phosphofructokinase deficiency

Abbreviation: PFKM
A glycogen storage disease caused by a deficiency of muscle phosphofructokinase and characterized by muscular weakness, and muscle cramps after exercise, hemolysis, hyperuricemia, and myoglobinuria.
Synonym: glycogen storage disease type VII; Tarui disease

deficiency of sweating


ZAP70 deficiency

Zeta-chain associated protein kinase deficiency.

zeta-chain associated protein kinase 70kDa deficiency

Abbreviation: ZAP70 deficiency
A severe combined immunodeficiency disease in which CD8+ T cells are missing from the circulation and the thymus develops abnormally.
Medical Dictionary, © 2009 Farlex and Partners

mental deficiency

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
The essentials of an inclusive concept of mental deficiency. American Journal of Mental Deficiency 46:214-219.
In the second letter Burke provided Hawks with statistics from specific clinical studies examining heredity and mental deficiency that suggested that mental deficiency was not primarily hereditary.
The problem of mental deficiency, Eugenics, democracy and social policy in Britain c.1870-1959.
Although the Bill itself did not focus on hereditary causes of mental deficiency, it did focus on incurable conditions and the debate in parliament was directed towards these issues.
"Some people don't know or can't talk about childhood sexual experiences--they might have been molested as a child, or they might have a mental deficiency and may not be able to recall things that have happened to them," Dr.
Brown has nurtured some fairly eccentric views over the past years; not least that eating pork can cause "mental deficiency".
"Mental deficiency" was listed as a contributing factor to his death.
Lewis Hershey, director of the Selective Service System, provided detailed testimony about the 18 percent of men who had been rejected for induction because of severe mental illnesses and the additional 14 percent who had been rejected because of mental deficiency; thus, one-third of America's potential fighting force was ineligible because of medical problems affecting their brains.
"Quick" and "clever" are synonymous while "slow" usually suggests mental deficiency. Philosophy can challenge this perspective when construed as it is here as the ongoing pursuit of wisdom rather than a grander species of cleverness.
Then, Matthew Thomson's follow-on chapter "Status, Manpower and Mental Fitness: Mental Deficiency in the First World War," makes the valuable point that matters such as mental deficiency and shell shock should be seen in the context of status.
Intelligence and achievement results varied from high average to severe mental deficiency. The study found that there is no consistent pattern of educational deficit or service requirement associated with FAS.