Characteristics Of A Chromosomal Disorder Essay - 955 Words

A chromosomal disorder is caused by an abundance or reduction of genes on the chromosomes. This type of disorder may also be caused by structural changes within these chromosomes; this is known as an aneuploidy (Porth, 2015). The most common chromosomal disorder is Down syndrome of which there are three types: complete trisomy 21, translocation, and mosaicism (Porth, 2015). Since its first identification in 1866, researchers have become more knowledgeable about the etiology of Down syndrome. When one studies etiology, pathogenesis, and clinical manifestations of Down syndrome, he or she will begin to understand multiple chromosomal disorders. Typically, the nucleus of each cell stores forty-six chromosomes. Half of these chromosomes derive from each parent cell. However, in those with Down syndrome, the cells contain forty-seven chromosomes. Researchers’ knowledge of the etiology of Down syndrome has grown since it was first described in 1866 by John Langon Down (National Dow n Syndrome Society, 2012). According to the National Down Syndrome Association (2012), 95% of the Down syndrome cases are caused by a fault in cell division. Although it is clear that this disorder occurs because of an alteration during cell division, the cause as to why this occurs is unknown. However, the pathogenesis of this disorder is clear. The pathogenesis of this disorder begins with nondisjunction during meiosis, which is failure of the chromosomes to separate. Today, it is known that thereShow MoreRelatedGenetic Disease : Turner Syndrome1104 Words   |  5 PagesIn 1938, Dr. Henry Turner first described Turner Syndrome. Turner Syndrome a genetic disease that only affects girls, in fact, it is one of the most common sexual development disorders (Radtke et al. 2014). It is caused by an abnormal sex chromosome, either an abnormal X chromosome or a missing X chromosome. The sex chromosome contributed by the father to the child determines the sex of the child because the moth er always contributes an X chromosome whereas the father can contribute either an X chromosomeRead MoreGenetic Disorders and Down Syndrome Essay969 Words   |  4 PagesA genetic disorder is a disease that is caused by an abnormality in an individuals DNA. Abnormalities can range from a small mutation in a single gene to the addition or subtraction of an entire chromosome or set of chromosomes† (Letsou). Most individuals are either related to or know someone who is effected by some type of disability. Many of these disabilities are caused by genetic disorders. Genetic disorders may alter physical appearance and cause mild to severe mental retardation. Fragile XRead MoreTurner Syndrome : A Chromosomal Disorder1165 Words   |  5 PagesTurner Syndrome Shinji Lin December 15, 2015 Period 5 Turner syndrome is a chromosomal disorder that affects development in females. This condition is caused by a missing or incomplete X chromosome. In 1938, Henry Turner, an American endocrinologist, described seven women with short stature, lack of sexual development, neck webbing (extra skin on neck), low hairline, and cubitus valgus (arms that turn out at the elbow). Years earlier, Otto Ullrich, a German geneticist, independently describedRead MoreDown Syndrome Essay1515 Words   |  7 PagesDown Syndrome Downs Syndrome, it is one of the most frequently occurring chromosomal abnormalities found in humans effecting people of all ages, races and economic levels. It is a chromosomal anomaly in cell development that results in a person being born with forty-seven chromosomes instead of the normal forty-six chromosomes. People with Down syndrome may have mild to severe learning disabilities and physical symptoms, which include a small skull, extra folds of skin under the eyes, andRead MoreGenetic Carrier Screening3033 Words   |  12 Pagesgenetic and chromosomal disorders which may affect offspring during after parturition. If tests are performed, one gains knowledge of any high risk genetic or abnormalities which may be present and carry a high risk of altering an individuals health. Genetics disorders are formed by a disease which is inherited genetically from parent to offspring. The genetic disorder results from a change in the DNA sequence. A chromosome abnormality is a missing or extra portion of chromosomal DNA. It canRead MoreA Brief Look at Down Syndrome670 Words   |  3 Pagesextra full or partial copy of chromosome 21. Down Syndrome is a chromosomal condition that causes low muscle tone, small stature, and a single deep crease across the center of the palm. Although, each person with Down Syndrome is a unique individual and may have these characteristics to different degrees. The cause of nondisjunction is still unknown, although scientists have made steps further to understanding this genetic disorder. For centuries, people with Down Syndrome were thought to need specialRead MoreTrisomy 18 Essay756 Words   |  4 PagesEdward’s Syndrome or also known as Trisomy 18 is a very serious and uncommon disorder, and there are three types of this disorder: Full, Partial, and Mosaic Trisomy 18. Trisomy 18 is a chromosomal condition that affects not only one part of the body, but usually many different limbs. Five to ten percent of the individuals with this disorder can live their lives with it, but they have to deal with severe disabilities. Since Edward’s Syndrome is not common, there are only a few solutions for theRead MoreThe Biological Nature Of Genes1063 Words   |  5 Pagessecond half progresses, Sturtevant discusses the beginnings of many modern-day topics and fields of Genetics. Through continued chromosomal study, Creighton and McClintock proved that chromosomes exchange parts during crossing over. Work is sex-determination was also continued by Morgan and Bridges in Drosophila to show non-disjunction and sex determining characteristics and genes. Muller’s work in evolution of mutations exposed the mutagenic effects of X-rays on genes and the danger that is posesRead MoreEssay about Down Syndrome941 Words   |  4 Pagesof these miracles learn that their children are â€Å"not normal.† Every year 6,000 parents across the country are informed that their child has a genetic disorder called Down Syndrome (â€Å"National Down Syndrome Society,† n.d.). 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