Fragile X Syndrome Case Studies

Fragile X syndrome, also called Martin-Bell syndrome, is a syndrome of X-linked mental retardation. In 1943, Martine and Bell described a pedigree of X-linked mental disability. Chris and Weesam were first to sight an unusual “maker X chromosome” with mental disability in 1969. It is also the most common known cause of autism. Autism is a brain development disorder that impairs social interaction and communication. It can also cause restricted and repetitive behavior. It all starts before a child is three years old. It affects about 1 in 4000 males and 1 in 8000 females. It can cause a range of mental impairment, varying from mild to severe, and can also cause many other typical features and symptoms. The cause of
fragile X syndrome is by mutation of a gene on the X- chromosome. The gene makes a protein needed for brain development, but the mutation causes a person to make less or none of the protein, which cause fragile X syndrome. That gene is called FMR1. FMR1 stands for fragile X mental retardation 1, which is a human gene that provides instructions to make a protein. The gene can be passed silently without any symptoms showing for generation before a child is affected by fragile X syndrome. Fragile X syndrome is inherited, mothers may be a carrier of the mutation and pass it on to their children or may have a pre-mutation that expands to a full mutation when passes on to the next generation. Girls have another X-chromosome, which usually does not have the mutation and can partially compensate for the nonfunctioning one.
Therefore, boys are affected more than girls are because boys have only one X chromosome. Physical characteristic s and behaviors portrays the symptoms of fragile X syndrome. Large or protruding ears and forehead, elongated face, large head, flexible finger joints, high palate, and flat feet are the physical characteristics. In addition, during a boy’s puberty, they usually develop large testicles and a long face. Behavioral symptoms include aggression in boys or shyness in girls. Attention deficit hyperactivity disorder and autistic behavior, such as hand flapping, hand biting, and chewing on clothes is part of behavior symptoms. In addition, anxiety, very sensitive to stimuli, great sense of humor, excellent memory, and frequent tantrums are signs of fragile X syndrome. For fragile X syndrome, there is, no cures but there are many treatments to help people who have the syndrome. There is hope that further understanding of its underlying causes would lead to new therapies. Early intervention in the pre-school years can help your child make better progress.
Speech and language therapy, occupational therapy, and physical therapy may be needed for a child to reach full potential. Avoiding over-stimulation and using calming techniques can help reduce behavior problems. Medications can be used to help treat the aggression, seizures, hyperactivity and short attention span that often come along with fragile X syndrome. In males, they have only one copy of the X chromosome. Males with significant trinucleotide expansion at the FMR1 locus are symptomatic, which means they are intellectually disabled. For females, the have two X chromosomes, so they have double chances of having a working FMR1 allele. Males cannot transmit fragile X syndrome to their sons, but they can transmit it to all of their daughters. Males who receive the fragile X are at high risk of intellectual disability. Females who are affected may appear normal or they may be intellectually disability and usually to a lesser degree than boys with the syndrome. The transmission of fragile X often increases with each passing generation. Genetic testing is available to diagnose fragile X syndrome and to
test for female carriers. People who develop mental delay, signs of autism, learning disability or mental retardation are recommended to test for the syndrome.
Whoever is related to someone that has the syndrome should also be tested.
Women with premature ovarian failure or early menopause may also be recommended to be tested. There are a number of tests to diagnose fragile X syndrome. Each test has it limitations, in many cases more than one test may be used. There are three most accurate tests in DNA testing. There are DNA molecular tests, chromosome test, and protein test.
DNA molecular tests count the number of CGG repeats in the promoter region of the FMR1 gene and check to see if the gene is inactive. Two main DNA test includes southern blot and polymerase chain reaction. Southern blot are studies on how quickly DNA pieces move through a liquid or gel when exposed to electricity. Polymerase chain reaction multiplies the amount of DNA being tested so it can be analyzed more quickly.
Chromosome test looks for the broken area of a chromosome using a microscope.
This test is recommended that another type of test be used to diagnose for fragile X syndrome. To confirm the diagnosis, the DNA test is needed. Protein test measures the amount of FMR1 that is produced by living cells. This is useful for screening large group of people for fragile X syndrome. DNA testing is also needed to confirm the diagnosis. For parents who are finding out that their child is affected with fragile x syndrome can be a terribly sad experience. The news can be seriously difficult to accept when the cause of the problem is hereditary. Parents who are learning about the disorder cause a grief reaction, mourning for the loss of hopes and expectations, which are part of every family. After many years of parents who learned about the diagnosis are often surprised by the intensity of their grief reaction. Feeling that something is wrong with them for becoming upset and depressed after they had gotten use to their child’s disability for years. This mourning is in fact a healthy way of dealing with bad news and a necessary step in accepting a genetic diagnosis. Seeking support from family, friends, and even professionals can be especially helpful in coping with these intense feelings. Often, talking with another parent who can identify with what you are going through is most helpful.