age of onset
person's age when developing or exhibiting symptoms of a disease or condition.
prenatal medical procedure that allows the detection of abnormalities (i.e. Down's) in the developing fetus. Involves the removal and analysis of amniotic fluid from the mother.
amyloid precursor protein
solid, waxy substance forming the core of the amyloid plaque characteristic of people with Alzheimer's disease.
pervasive developmental disorder characterized by impairments in social relationships and restricted or unusual behaviors, but without the language delays seen in autism.
attention deficit/hyperactivity disorder (ADHD)
developmental disorder featuring maladaptive levels of inattention, excessive activity, and impulsiveness
augmentative communication strategies
pictures or computer aids to assist people with communication deficits so that they can communicate.
autistic disorder (autism)
pervasive developmental disorder characterized by significant impairment in social interactions and communication and restricted patterns of behavior, interest, and activity.
childhood disintegrative disorder
pervasive developmental disorder involving severe regression in language, adaptive behavior, and motor skills after a 2- to 4-year period of normal development.
problems in transmitting or conveying information, including stuttering, selective mutism, and expressive language disorder.
cultural-familial mental retardation
mild mental retardation that may be caused largely by environmental influences
arrangement of experiences in which the person or animal learns to respond under certain conditions and not to respond under other conditions
disorder of written expression
condition in which writing performance is significantly below the standard for that age level
type of mental retardation caused by a chromosomal aberration (chromosome 21) and involving characteristic physical appearance. Sometimes known as trisomy 21.
learning disability involving problems in reading.
educable mental retardation
obsolete term referring to level of retardation comparable to the DSM mild designation that assumes the individual can learn basic academic skills
expressive language disorder
an individual's problems in spoken communication, as measured by significantly low scores on standardized tests of expressive language relative to nonverbal intelligence test scores. Symptoms may include a markedly limited vocabulary or errors in verb tense. expressive language is less than receptive language
extensive support retardation
retardation level characterized by the long-term and regular care required for individuals with this degree of disability
fragile X syndrome
pattern of abnormality caused by a defect in the X chromosome resulting in mental retardation, learning problems, and unusual physical characteristics
intermittent support retardation
retardation level characterized by the need for only episodic special care. For example, during crises and difficult life changes.
reading, mathematics, or written expression performace substantially below levels expected relative to the person's age, IQ score, and education.
X-linked disorder characterized by mental retardation, signs of cerebral palsy, and self-injurious behavior
limited support retardation
retardation level characterized by the special care needed on a consistent although time-limited basis. for example, during employment training.
maintenance of sameness
necessity among people with autism that their familiar environments remain unchanged. They become upset when changes are introduced.
mathematics performance significantly below the standard for that age level
significantly subaverage intellectual functioning paired with deficits in adaptive functioning such as self-care or occupational activities, appearing before age 18
mild mental retardation
level of retardation defined by IQ scores between 55 and 70
moderate mental retardation
level of retardation defined by IQ scores between 40 and 55
in Down syndrome, the failure of two of the 21st chromosomes to divide to create one cell with one copy that dies and one cell with three copies that continue to divide.
pervasive developmental disorders
wide-ranging, significant, and long-lasting dysfunctions that appear before the age of 18
pervasive support retardation
retardation level characterized by the constant, intensive care needed by the individual in all environments
recessive disorder involving the inability to break down a food chemical whose buildup causes retardation, seizures, and behavior problems. PKU can be detected by infant screening and prevented by a specialized diet.
profound mental retardation
levels of retardation defined by IQ scores below 20 and extremely limited communication and self-help skills
the study of how genetic makeup can affect individual reactions to drugs
reading performance significantly below the standard for that age level
communication material that is understood rather than expressed
intervention for stuttering in which the person is instructed to stop and take a deep breath whenever a stuttering episode begins
progressive neurological developmental disorder featuring constant hand-wringing, mental retardation, and impaired motor skills
developmental disorder characterized by the individual's consistent failure to speak in specific social situations despite speaking in other situations
dangerous actions, including head-banging and hitting oneself, seen in many children with autism.
severe mental retardation
level of retardation defined by IQ scores between 20 and 40 and somewhat limited communication, self-help, social, and vocational skills
disturbance in the fluency and time patterning of speech (i.e. sound and syllable repetitions or prolongations)
method for evaluating a skill to be learned, breaking it down into its component parts.
disruption in early development involving involuntary motor movements or vocalizations
sudden, rapid, recurrent involuntary motor movements or vocalizations
developmental disorder featuring multiple dysfunctional motor and vocal tics
trainable mental retardation
obsolete term referring to the level of retardation comparable to the DSM's moderate designation. suggests the individual can learn rudimentary vocational but not academic skills.
rare dominant gene disorder characterized by bumps on the skin and sometimes mental retardation and seizures.