Fragile X Syndrome is a genetic condition that effects part of the X Chromosome. Fragile X Syndrome (Martin Bell Syndrome) was first realized in 1943 by J. Purdon Martin and Julia Bell who showed that mental disabilities were located and passed down via X chromosomes through the description of pedigrees featuring x-linked mental disabilities. Later, in 1969, Herbert Lubus noticed an unusual "marker X chromosome" associated with mental disabilities. In that same year, Lubus developed a chromosomal test for the condition, even though the test wasn't popularized until the early '70's. Around the time that Lubus' test became widely used, Frederick Hecht coined the term "fragile" to describe the state of the X Chromosome. Finally, the most ground breaking achievement in Fragile X research was the identification of the the FMR1 gene as the cause of Fragile X Syndrome in 1991.
Symptoms:
Fragile X Syndrome is related to a myriad of behavioral and physical disabilities, most notably being autism. There are both physical and behavioral/mental symptoms that suggests Fragile X Syndrome during the prognosis of disabilities. Behavioral symptoms may include a delay in normal movements (walking, crawling, twisting, etc.) as an infant, spontaneous hand clapping or biting, other hyperactive or impulsive behaviors, cognitive impairment, speech/language delays, and tendencies to be socially withdrawn (such as avoiding eye contact). Physically, the effected might have symptoms such as flat feet, flexible joints accompanied by low muscle tone, large build, abnormally large forehead or ears with a prominent jaw, a long face, and soft skin. Some symptoms may be present at birth, however, there could be no sign of Fragile X Syndrome until after puberty. Because this disorder is located at the FMR1 gene on the X chromosome, naturally, symptoms are more prominent in men than women, however, women may experience symptoms even if they are only a carrier. The severity of the symptoms are dependent upon the number of replicas of the FMR1 gene present in the X chromosome. Due to the complexity of the disorder, a woman could be classified as a carrier, but experience symptoms as severe as mental retardation, as mild as premature menopause or infertility, as normal as poor coordination, or none at all. All of which are solely dependent on the FMR1 gene and its replicated gene code.
Diagnosis:
Fragile X Syndrome is caused by a replication in the gene code of the FMR1 gene at a fragile part of the X chromosome. The FMR1 gene is responsible for the production of a protein that regulates brain growth and development. The more copies in the FMR1 gene code made, the less the protein is synthesized resulting in the likelihood of mental and physical disabilities. Fragile X (when present in parents) is a recessive, sex-linked, trait, therefore, the disorder can only be diagnosed through genetic testing. Since there is only one way to test for Fragile X, most people (if diagnosed at all) usually find out as a result of pre-diagnosis of some form of cognitive impairment such as autism.
Prognosis/Treatment:
Women who have Fragile X Syndrome typically experience less severe symptoms and are able to live fairly normal lives. In men, however, Fragile X most commonly leads to some form of mental disability and, depending once again on the number of replications in the FMR1 gene code, can have a crippling effect on social development. Though there is no cure or initial treatment, through education, training, and physical/mental rehabilitation, the affected become able to function at as high a level as possible.
Breakthroughs/Prevention:
Because Fragile X Syndrome is a genetic disorder, the only way to prevent it is through careful genetic counseling and planning when the option of pregnancy opens to an affected individual or carrier. Also due to the disorder being genetically sex-linked based, there has not been any recent developments in Fragile X "research" however, there have been a huge breakthrough in Fragile X support groups such as the Friends for Fragile X, and the National Fragile X Foundation.
Нема коментара:
Постави коментар