Conditions

Hearing impairment is defined by the Individuals with Disabilities Education Act (IDEA) as, "[...] an impairment in hearing, whether permanent or fluctuating, that adversely affects a child's educational performance." Deafness is defined as, "[...] a hearing impairment that is so severe that the...

The term "developmental disorder" or "developmental disability" means a severe, chronic disability of an individual that: is attributable to a mental or physical impairment, or combination of mental and physical impairment is manifested before the individual attains the age of 22 is likely to...

Down syndrome is a genetic disorder that occurs in approximately one of 800 live births. It is caused most often by an abnormality during cell division in gamete formation called nondysjunction. As a result, the fertilized egg will contain three copies of chromosome 21. The extra chromosome...

It is a disorder that affects boys almost exclusively. Parents may first see that their three-to-five year old child has frequent falls, runs slowly, or has toe-walking or a waddling gait. The child’s calves are often unusually large. Weakness is initially most pronounced in the hips and upper leg...