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Introduction
Fragile X syndrome also known as Martin-Bell syndrome is a HYPERLINK “http://en.wikipedia.org/wiki/Genetic_disorder” o “Genetic disorder” genetic HYPERLINK “http://en.wikipedia.org/wiki/Syndrome” o “Syndrome” syndrome usually considered as the most commonly inherited mental disorder HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Randi+Jenssen+Hagerman%22&source=gbs_metadata_r&cad=12” (Hagerman, & HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Paul+J.+Hagerman%22&source=gbs_metadata_r&cad=12” Hagerman, 2002). It results from mutation or a change in a single trinucleotide gene on the X chromosome leading to abnormal neural development since the protein coded by the fragile X mental retardation 1 gene can not be expressed. The syndrome is characterized by a wide range of intellectual and physical limitations as well as behavioral and emotional aspects ranging from mild to severe symptoms. According to Upner (2007) the most consistent and conspicuous effect of this syndrome is on the intelligence of the affected. For instance, more than three quarters of the affected males have a low IQ of about 75 or less. This is however varied in females where the affected may have low or normal IQ. Fragile X can therefore be easily transferred across different families irrespective of class or ethnicity and also passed from generation to generation through genetic inheritance (Upner, 2007).
Cause of Fragile X Syndrome
As mentioned above, Fragile X Syndrome is a genetic disorder usually caused by a change or mutation of the fragile X mental retardation 1 gene found on the X chromosome. It is noteworthy that genes usually contain information needed for making of at least a single protein code (Upner, 2007). When changes occur in the genes, the cells may not be able to make the proteins or even provide a form of protein required by the body. The failure of fragile X mental retardation 1 gene to make normal quantities of usable Fragile X Mental Retardation Protein (FMRP) causes Fragile X disorder. The severity of the disorder is determined by the amount of FMRP in the body. Fragile X syndrome is severe in circumstances where such proteins are insufficient in the body and mild when normal levels of the proteins are present. The gene activity level in structuring of FMRP in the body is usually controlled by the repeats of a cytosine-guanine-guanine (CCG) sequence contained in the promoter region of the FMR1 gene. The number of CCG repeats vary among different people with the normal beings having an average of thirty CCG repeats ranging from 6-55 repeats while individuals having Fragile X syndrome have even more than 200 repeats. Basically, the more than 200 CCG repeats inactivates genes through a process called methylation hence cells are unable to make the FMRP.
Inheritance patterns
Due to the fact that both females (XX) and males (XY) have at least an X chromosome, they can therefore pass on to their offspring the mutated gene. Upner (2007) argues that this is possible since Fragile X gene is carried on the X chromosome. If a father has an altered X chromosome and the mother has normal X chromosome, all the sons would be free from genes for Fragile XZ while all the couple’s daughters would have the altered Fragile X genes as illustrated in the diagram below. A father can only pass an altered gene to a daughter and not son since the Fragile X gene is only carried on the X chromosome (Upner, 2007).
Father
Y XFragile
Mother
X Boy
XY Girl
XXFragile
X Boy
XY Girl
XXFragile
Fathers can only pass on the premutation form of the FMR1 gene to their daughters even if they have full mutation. This implies that a daughter will only get a milder form of Fragile X upon inheriting a mutated FMR1 gene from her father. On the other hand, mothers can pass on Fragile X genes to either daughter or sons since she is only able to pass on single X chromosome.
Symptoms and recognition of Fragile X Syndrome
Even though different individuals with Fragile X disorder present different symptoms, they usually share a set of social, physical, sensory as well as mental characteristics due to the little amount of FMRP in their cells (Upner, 2007). Generally, the signs and symptoms of Fragile X disorder are categorized into five main groups namely; physical, sensory, social and emotional, intelligence and learning as well as speech and language (Upner, 2007). For instance, many people with this disorder have impaired mental functioning hence their ability to think, reason, as well as learn is highly affected. An intelligence Quotient test is used to determine the intelligence levels of individuals suffering from Fragile X syndrome. According to researchers the IQ of such individuals is always 75 or less unlike normal beings whose IQ range from 85 and 115. Physically, individuals with Fragile X syndrome have unique characteristics including longer jaw or face and larger ears HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Randi+Jenssen+Hagerman%22&source=gbs_metadata_r&cad=12” (Hagerman, & HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Paul+J.+Hagerman%22&source=gbs_metadata_r&cad=12” Hagerman, 2002). They are always shorter than their peers. Moreover, macro-orchidism is exhibited among affected individuals at puberty. This entails the enlargement of male testicles among individuals with Fragile X disorder. The affected children suffer from social anxiety hence may even attempt to avoid social situations. They feel nervous and uncomfortable in the company of others. Besides, males with Fragile X are easily upset by sounds and sights.
Treatment of Fragile X Syndrome
Currently, there is no single definitive treatment for Fragile X despite proposal of several medications for the disorder. However, there are three basic options for treating the disorder. These options include medication options, educational options, as well as therapeutic options HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Randi+Jenssen+Hagerman%22&source=gbs_metadata_r&cad=12” (Hagerman, & HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Paul+J.+Hagerman%22&source=gbs_metadata_r&cad=12” Hagerman, 2002). To begin with, individuals with Fragile X disorder in their family tree may be subjected to genetic counseling in an attempt to assess the possibility of bringing forth affected children as well as the severity of the offspring (Hughes, 2004). A special and free education is also guaranteed to children with Fragile X syndrome from the age of three according to the existing Federal laws in the U.S. The children with disabilities are able to learn with ease as the learning facilities are made available under the Individuals with Disabilities Education Act of 1997(Hughes, 2004)
Finally, professionals can also help individuals with Fragile X syndrome and their families tackle the symptoms of the disorder. Therapeutic assistance is best provided by health care experts such as occupational therapist who would teach the family of the affected child on how to adjust conditions as well as tasks to suit the desire and ability of an individual (Hughes, 2004). For instance, parents of the affected child may be taught on how to massage their patient to calm her down. Corrective heart surgery as well as ADHD medications can also be used in the treatment of FXS HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Randi+Jenssen+Hagerman%22&source=gbs_metadata_r&cad=12” (Hagerman, & HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Paul+J.+Hagerman%22&source=gbs_metadata_r&cad=12” Hagerman, 2002).
Life expectancy of Fragile X syndrome
Generally, there is no concrete evidence on the impact of Fragile X disorder on the affected individuals. The life expectancy however varies from one person to another depending on the severity of the condition. Patients with Fragile X Syndrome will have a normal life expectancy for the most part. Such mutation leads to the failure by the aforementioned gene to make normal amounts of FMRP in the cell (Upner, 2007).
Conclusion
Fragile X Syndrome is a genetically inherited disorder characterized by intellectual and physical limitations as well as behavioral and emotional features ranging from mild to severe symptoms. It results from mutation of a fragile X mental retardation 1 gene found on the X chromosome. The Fragile X gene is carried on the X chromosome and may therefore be passed on to the children from the parents as explained above. The Syndrome presents varied signs and symptoms including HYPERLINK “http://en.wikipedia.org/wiki/Fragile_X_syndrome” l “Physical_phenotype” social anxiety, mental retardation, hypersensitivity as well as physical characteristics. The disorder has no specific cure but can be treated through medical options, therapeutic options as well as education options. All the three options help the affected and their families in managing the symptoms of the disorder. Finally, it is worth noting that the disorder has no impact on the life span of the affected individuals. However, the severity of the disorder may cause the variance of life expectancy from one person to the other (Upner, 2007).
Reference list:
HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Randi+Jenssen+Hagerman%22&source=gbs_metadata_r&cad=12” Hagerman, R. & HYPERLINK “http://www.google.co.ke/search?tbs=bks:1&tbo=p&q=+inauthor:%22Paul+J.+Hagerman%22&source=gbs_metadata_r&cad=12” Hagerman, P. (2002). Fragile X syndrome: diagnosis, treatment, and
research. 3rd Ed. Maryland: JHU Press.
Hughes, D. (2004). Educating children with fragile X syndrome: a multi-professional. New
York: Routledge.
Upner, J. (2007). New Research on Fragile X Syndrome. New York: Nova Publishers.
