Isaac Thomas
Rett Syndrome
Rett syndrome is a progressive neurological disorder that affects almost exclusively in females. The most basic symptoms include decreased speech, cognitive disabilities, severe lack of muscle control, small head size, and unusual hand movements. A woman with a mutation in her MECP2 gene, has a 50% risk with any pregnancy to pass on her X chromosome with the mutation. It is not common for women with Rett syndrome to have children because the severity of the disorder. The mutated gene on the X chromosome that is responsible for causing Rett syndrome is the methyl CpG-binding protein 2, MECP2 gene. The gene makes a protein that controls other genes. When a mutation occurs in the MECP2, the protein it makes does not work properly. This is thought to counteract normal neuron, nerve cell development. The severity of the syndrome in females is related to the type of mutation in the MECP2 gene and the percentage of cells that carry a normal copy of the MECP2 gene. Rett syndrome is believed to affect all ethnic groups and nationalities with an equal frequency of about 1 case for every 10,000 to 15,000 live female births.
Rett syndrome is an X-linked dominant gene. This means that the mutation responsible for Rett syndrome affects the gene located on the X chromosome. Females attain two X chromosomes, one from each parent. Males have one X and one Y chromosome. There is no cure for Rett syndrome. Treatment of patients with Rett syndrome focuses on improving the symptoms present. Treatment may include medications that constrain seizures, reduce spasticity, and prevent sleep disturbances. Nutrition is supervised in females with Rett syndrome due to their small build and the constipation related with the...
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...romosome they carry cannot compensate for this mutation on their X chromosome. Females with a mutation in the gene that causes Rett Syndrome are able to survive because the presence of the second normal X chromosome partially compensates for the mutation on the other X chromosome.
Bibliography
1. "Rett syndrome." Holly A. Ishmael, MS, CGC. and Tish Davidson, A.M. The Gale Encyclopedia of Neurological Disorders, Second Edition. Ed. Brigham Narins. Detroit: Gale, 2012. 2 vols.
2. "Rett syndrome." Holly A. Ishmael, MS, CGC. The Gale Encyclopedia of Genetic Disorders. Ed. Laurie Fundukian. 3rd ed. Detroit: Gale, 2010. 2 vols.
3. "Rett syndrome." Rebecca J. Frey, PhD., Emily Jane. Willingham, PhD., and Laura Jean Cataldo, RN, EdD. The Gale Encyclopedia of Mental Health. Ed. Kristin Key. 3rd ed. Detroit: Gale, 2012. 2 vols.
Rett syndrome is a postnatal neurodevelopmental disorder that mainly affects girls but is rarely found in boys as well. Rett syndrome strikes all racial and ethnic groups, and occurs worldwide in 1 of every 10,000 female births. It was first identified by Dr. Andreas Rett, an Austrian physician who described it in an article published in 1966. Even though Rett described the disorder in his 1966 article it went another 17 years until being generally recognized after Swedish researcher Dr. Bengt Hagberg published an article about the disorder in 1983 (Rett Syndrome Fact Sheet).
Genetic disorders can be caused by many of the 46 chromosomes in human cells. This specific disorder is linked to a mutation in the long arm of the X, or 23rd chromosome. The mutation is recessive, meaning a normal X chromosome can hide it. Females have two X chromosomes allowing them to hide the mutated recessive one, making them a carrier of the gene, while males only have one X chromosome, meaning that they are unable to hide the mutation and they become effected by the disease. Therefore if a male carries the gene, he is affected because he has no way of dominating the recessive gene, but if a female carries it, she is only a carrier and has a 50/50 chance of passing it on to her baby. This may seem like a high probability however, only one in every fifty thousand male births will have this immunodeficiency disease.
Turner’s syndrome is a genetic conditions that affects the female’s sex chromosome. In (http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001417/) Turner’s syndrome occurs when cells are missing all or part of an X chromosome. It’s common of the female patient to only have one X chromosome. Although, some individuals may have two X chromosomes but one is defective. It is thought that an estimated 1 out of 2000-2500 females suffer from this genetic condition worldwide but it’s usually females with this condition don’t survive their birth. Due to this abnormality, the genes that is defective “affect the growth and sexual development of the female” (http://learn.genetics.utah.edu/content/disorders/whataregd/turner/). However other disabilities and delays do occur even though these traits can vary case by case.
The Duchenne gene has been located on the short arm of the X chromosome. This means that Duchenne muscular dystrophy is inherited as an X-linked recessive disease. Females have two X chromosomes, while males have one X chromosome and one Y chromosome. Therefore, in females, a normal X...
As you know, Robert was diagnosed with Duchenne Muscular Dystrophy last week. I share my condolences for your family, as this must be a tough time for the both of you. In this letter there will be information regarding what Duchenne Muscular Dystrophy is, how it is caused, how it is treated, and the daily life of those affected by Duchenne Muscular Dystrophy and their family members. Muscular Dystrophies are genetic disorders that are distinguished by degenerative muscles and weakness in the muscles. Duchenne muscular dystrophy is a dominant sex-linked disorder that mostly affects males, and it affects one in 3,500 males (Furlong, 2015).
Myotonic dystrophy, type 1, is a genetic disorder which is linked to chromosome number 19 in humans. The dystrophia myotonica protein kinase gene is located on the q arm of the chromosome at the locus of 13.32. It is an autosomal dominant disorder, which means that the individuals that are affected by this disorder and contain at least one dominant allele for the dystrophia myotonica protein kinase gene. The disorder is caused by a series of repeats of a trinucleotide region that is expanded beyond the normal levels (Musova et al., 2009). The trinucleotide region is a series of repeats of CTG in the untranslated region of the dystrophia myotonica protein kinase gene. The severity of the disorder is associated with the number of repeats the individual has within the gene. Normal individuals tend to have between 5 and 37 repeats while an individual with a very mild myotonic dystrophy may have 50 to 150 repeats, and if the disorder is discovered at the time of birth the individual will have over 2,000 repeats of the trinucleotide region (Musova et al., 2009). Myotonic dystrophy, type 1, affects multiple organ systems of the body and is relatively slow to progress. Myotonic dystrophy, type 1, is categorized by alterations of the beating pattern of the heart, faulty dystrophin proteins, clouding of the lens of the eye, decreased functionality of the gonads, balding, and myotonia (Musova et al., 2009). Myotonia is described as the slow relaxation of any muscle type, which will cause the individual to use extended effort to simply relax the muscles after they have been contracted. Muscular dystrophy causes an individual to experience muscular deg...
Every cell contains forty-six chromosomes (twenty-three pairs). One, out of the twenty-three pairs, is in control of a person’s gender. There two different kinds of chromosomes: X and Y. Males are born with one X chromosome and one Y chromosome. Females, however, are born with two X chromosomes. According to Cindy Dunham and Catherine H. Ward, girls with Turner syndrome are missing part of, or all of the X chromosome (3). The chromosome becomes absent before or shortly after conception (Overview par. 3). Girls diagnosed with Turner syndrome are confirme...
People with translocation Down syndrome can inherit the condition from an unaffected parent. The parent carries a rearrangement of genetic material between chromosome 21 and another chromosome. This rearrangement is called a balanced translocation. No genetic material is gained or lost in a balanced translocation, so these chromosomal changes usually do not cause any health probl...
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He published a comprehensive medical description of the syndrome. It was not until 1959, that it became clear the syndrome was due to lack of sex chromosome material. Turner's Syndrome is a rare chromosomal disorder that affects one in approximately 2,500 females. Females normally have two X-chromosomes. However, in those with Turner's Syndrome, one X chromosome is absent or is damaged.
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