Autism Resource Center - Articles
Problems That May Accompany Autism Spectrum Disorders
When children's perceptions are accurate, they can learn from what they see, feel, or hear. On the other hand, if sensory information is faulty, their experiences of the world can be confusing. Many children with autism spectrum disorders (ASD) are highly attuned or even painfully sensitive to certain sounds, textures, tastes, and smells. Some children find the feel of clothes touching their skin almost unbearable. Some sounds--a vacuum cleaner, a ringing telephone, a sudden storm, even the sound of waves lapping the shoreline--will cause these children to cover their ears and scream.
In ASD, the brain seems unable to balance the senses appropriately. Some children with ASD are oblivious to extreme cold or pain. A child with ASD may fall and break an arm, yet never cry. Another may bash his or her head against a wall and not wince, but a light touch may make the child scream with alarm.
Many children with ASD have some degree of mental impairment. When tested, some areas of ability may be normal, while others may be especially weak. For example, a child with ASD may do well on the parts of the test that measure visual skills but earn low scores on the language subtests.
One in four children with ASD develops seizures, often starting either in early childhood or adolescence.1 Seizures, caused by abnormal electrical activity in the brain, can produce a temporary loss of consciousness (a "blackout"), a body convulsion, unusual movements, or staring spells. Sometimes a contributing factor is a lack of sleep or a high fever. An EEG (electroencephalogram--recording of the electric currents developed in the brain by means of electrodes applied to the scalp) can help confirm the seizure's presence.
In most cases, seizures can be controlled by a number of medicines called "anticonvulsants." The dosage of the medication is adjusted carefully so that the least possible amount of medication will be used to be effective.
Fragile X Syndrome
This disorder is the most common inherited form of mental retardation. It was so named because one part of the X chromosome has a defective piece that appears pinched and fragile when under a microscope. It is important to have a child with ASD checked for Fragile X, especially if the parents are considering having another child. If a child with ASD also has Fragile X, there is a 1 in 2 chance that boys born to the same parents will have the syndrome.2 Other members of the family who may be contemplating having a child may also wish to be checked for the syndrome.
A distinction can be made between a father's and mother's ability to pass along to a daughter or son the altered gene on the X chromosome that is linked to fragile X syndrome. Because both males (XY) and females (XX) have at least one X chromosome, both can pass on the mutated gene to their children.
A father with the altered gene for Fragile X on his X chromosome will only pass that gene on to his daughters. He passes a Y chromosome on to his sons, which doesn't transmit the condition. Therefore, if the father has the altered gene on his X chromosome, but the mother's X chromosomes are normal, all of the couple's daughters would have the altered gene for Fragile X, while none of their sons would have the mutated gene.
Because mothers pass on only X chromosomes to their children, if the mother has the altered gene for Fragile X, she can pass that gene to either her sons or her daughters. If the mother has the mutated gene on one X chromosome and has one normal X chromosome, and the father has no genetic mutations, all the children have a 50-50 chance of inheriting the mutated gene.
The odds noted here apply to each child the parents have.3
In terms of prevalence, the latest statistics are consistent in showing that 5% of people with autism are affected by Fragile X and 10% to 15% of those with Fragile X show autistic traits.
Tuberous sclerosis is a rare genetic disorder that causes benign tumors to grow in the brain as well as in other vital organs. It has a consistently strong association with ASD. One to 4% of people with ASD also have tuberous sclerosis.4
- Volkmar, F.R. (2000). Medical problems, treatments, and professionals. In M.D. Powers (Ed.), Children with autism: A parent's guide, 2nd Ed., (pp.73-74). Bethesda, MD: Woodbine House.
- Powers, M.D. (2000). What is autism? In M.D. Powers (Ed.), Children with autism: A parent's guide, 2nd Ed. , (p. 28). Bethesda, MD: Woodbine House.
- U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health (NIH), National Institute of Child Health and Human Development. (2003). Families and Fragile X Syndrome. National Institute of Child Health and Development (NICHD) (NIH Publication No. 96-3402).
- Smalley, S.I., (1998). Autism and tuberous sclerosis. Journal of Autism and Developmental Disorders, 28(5), 407-414.