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| | mental disability - Hutchinson encyclopedia article about mental disability |
 | | Clinically, mental disability is graded as profound, severe, moderate, or mild, roughly according to IQ and the sufferer's ability to cope with everyday tasks. |
 | | Among its many causes are genetic defect (phenylketonuria), chromosomal errors (Down's syndrome), infection before birth (rubella) or in infancy (meningitis), trauma (brain damage at birth or later), respiratory difficulties at the time of birth, toxins (lead poisoning), physical deprivation (lack of, or defective, thyroid tissue, as in cretinism), and gross psychological deprivation. |
 | | A person may be born with a mental disability (for example, Down's syndrome) or may acquire it through brain damage. |
| encyclopedia.farlex.com /mental+disability (220 words) |
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