Down Syndrome
Down syndrome is a genetic condition caused by the presence of an extra chromosome.
While students with Down syndrome may share certain physical traits, each student is an individual and the level of general learning disability will range from mild to profound. The student with Down syndrome may have problems such as heart defects, respiratory problems and eye defects, and may variously exhibit the following characteristics: auditory and visual impairment, delayed fine- and gross-motor skills, difficulties with thinking and reasoning and applying knowledge in new situations, limited concentration span, poor auditory memory, speech and language impairment and sequencing difficulties.
Generally speaking the student with Down syndrome will be better able to understand language than to communicate it expressively. Consequently cognitive skills are often underestimated. Each student with Down syndrome should be treated as an individual whose education is based on an assessment of his/her strengths and needs.
Rett/ Rhett Syndrome
Rett/Rhett syndrome affects females almost exclusively and is a neurodevelopmental condition characterised by ‘normal’ early development followed by a period of regression where skills are lost. As with any syndrome there is huge variation in those with Rett/Rhett syndrome and deterioration, in varying degrees, may be noticed in expressive language use, gait, general learning ability, purposeful use of hands, distinctive head movements and head growth.
Rett/Rhett syndrome is classified as a developmental disorder of childhood. The symptoms are generally described in terms of four stages:
Stage 1: Early Onset (6–18 months of age): the slowing of development is generally subtle at this stage and consequently symptoms are often overlooked.
Stage 2: Rapid Deterioration/Destruction (1–4 years of age): this stage may be gradual or rapid. Typically, purposeful hand use and spoken language are lost at this stage. Gait patterns are laboured and unsteady, and periods of trembling or shaking may be evident. Slowing of head growth may be noticeable. Behaviours such as hand-wringing, hand-clapping or grinding of teeth may present.
Stage 3: Plateau/Pseudo-stationary (2–10 years of age): apraxia (difficulties controlling voluntary muscular movements in spite of the fact that there is no actual muscle weakness), motor difficulties and seizures may present at this stage. Alertness, attention span and communication skills may improve as may a general interest in the individual’s surroundings.
Stage 4: Late Deterioration of Motor Skills (typically 10 years onwards): this stage can last for a number of decades and is characterised by reduced mobility, muscle weakness, rigidity, spasticity and scoliosis. The individual may lose the ability to walk (if he/she managed to acquire this skill) at this stage. Repetitive hand movements and seizures may decrease and eye gaze may improve. It is important to note that there is no cognitive loss at this stage.
Tourette Syndrome
It is essential that multiple motor tics (twitches) and one or more vocal tics (noises) are present for at least one year for a definitive diagnosis of Tourette syndrome. These tics may appear simultaneously or at different times and will tend to fluctuate in occurrence and intensity. The onset of symptoms is usually before the age of twenty-one with the average age of onset being seven. Tourette syndrome is biochemically based and genetically transmitted. Motor and vocal tics may be simple or complex.
Simple motor tics include tics of the head and face such as eye blinking, squinting, eye rolling, nose twitches, mouth twitches, making faces, tongue protrusion, nodding or tilting of the head sideways, shoulder shrugging, arm jerking and extending, leg kicking and knee jerks, and abdominal contractions such as pulling in the tummy. Complex motor tics include the smelling and licking of objects, spitting, touching parts of one’s own body and touching others, and unusual gaits such as twirling, squatting, hopping, skipping and bending down.
Simple vocal tics include sounds such as repetitive sniffing, snorting, throat clearing, coughing and gulping, while more complex vocal tics include grunting, barking, yelping, quacking, whistling and belching.
Other characteristic features of the syndrome can include palipraxia (repetitive movements such as knotting a tie over and over again), echopraxia (copying or imitating what other people do), echolalia (repeating or imitating what people say), palilalia (repeating oneself over and over, or constantly repeating the last word or phrase uttered by oneself) and copraxia (involuntary inappropriate cursing and swearing).
Most students with Tourette syndrome test within average limits on standardised IQ (Intelligence Quotient) tests. The difficulties experienced by students with Tourette syndrome in the classroom are often related to the symptoms of the disorder themselves (such as when tics disrupt other classmates or interfere with handwriting or participation in class discussions). Some difficulties are caused by co-existing symptoms such as obsessive compulsive behaviour and attention deficit hyperactivity disorder (ADHD), while others are associated with learning and academic learning difficulties. Tics such as severe head shaking, neck stretching or eye rolling may cause the student to be unable to look directly at the teacher or read easily. Hand tics often interfere with legibility of handwriting and visual spatial deficits may result in the student having difficulty with copying from the board or elsewhere. Tics may also impede activities that have strict timing criteria, which may result in lowered test scores and associated inaccurate estimates of ability.
Turner Syndrome
Turner syndrome is a chromosomal condition that exclusively affects females. The syndrome occurs when one of the two X chromosomes normally found in females is missing or contains certain structural defects.
Common characteristics associated with Turner syndrome may include short stature and a lack of ovarian development. Other physical characteristics such as a webbed neck, low set ears, low hairline, puffy hands and feet and/or arms that turn out slightly at the elbow may also be present. Some individuals with the syndrome may have scoliosis, dislocated hips, cardiovascular problems, kidney abnormalities and/or hearing difficulties. It is important to be aware that each individual presents with different combinations of symptoms.
In the school situation the student with Turner syndrome may experience difficulties with mathematical and visual spatial problems. Social and/or emotional problems may also present. Research suggests that girls with Turner syndrome are weak in mathematical achievement relative to reading achievement and verbal performance.