Introduction to Turner Syndrome
Turner Syndrome is the absence or abnormality of the X chromosome. This "abnormality" can occur on the X chromosome, when either parts of the q or p arm(s) of the chromosome is missing or when the chromosome adopts an unusual shape [4]. These missing genes, or missing chromosome creates various complex symptoms and characteristics on the individual who has Turner Syndrome.
The term chromosome most commonly exists as single structures called un-replicated chromosomes, these chromosomes contain an identical copy of its self called a chromatid. In total the Human body contains 46 chromosomes, which exist in 23 pairs. Each of these pairs are called a homologous chromosome or homologous pairs because they essentially carry variations of the same genetic information. Within the homologous pairs, one of the chromatins is called the paternal homologue which are from the father and the other, maternal homologue from the mother. These chromosomes are very important as they consist of chromatin (strands of DNA). This DNA is the building block of life; it is compacted tightly and coiled up forming the shape of a chromosome. These chromosomes are found in the nuclei of eukaryotic cells and contain the genetic makeup of each individual [5]. Specific genes that are located on the chromosomes can sometimes be defected or mutated, these mutations can be responsible for genetically induced abnormalities. An example of these genetic abnormalities would be; Huntington’s Disease, Klinefelter Syndrome and Downs Syndrome just to name a few. |
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A Biological term that best describes Turner Syndrome is Monosomy. Monosomy is the presence of only one chromosome, or lack of a chromosome in the normal complement. Monosomy is also a form of Aneuploidy. An Aneuploidy is an individual organism (in this case human) by which its chromosome count differs from the standard laboratory count of a chromosome set. [6] This is essentially what Turner syndrome is, as shown in Figure 1.3. Where the red arrows are present, there is a whole sex chromosome that is absent from the image or standard laboratory count of chromosomes in Humans. How prevalent is Turner Syndrome? Turner syndrome is a sporadic event that affects 1 in every 2,500 live female births, which converts to 108,800 females who live with this disease in the USA alone. In Australia there are extrapolated prevalence statistics to suggest that 7,965 individuals in Australia that are living with Turner Syndrome (This was assumed from a population of 19,913,1442) [7]. These statistics from the USA suggest that there are 108,800 females in total that struggle with poor social skills, numerical ability and memory defects. |
Reference List
[1]U.S National Library of Medicine. (2012). Turner Syndrome. Available: http://ghr.nlm.nih.gov/condition/turner-syndrome. Last accessed 10th August 2014.
[2] Health Grades Inc, Right Diagnosis from Health Grades, Statistics by country for Turner Syndrome, 2014 Accessed on 23rd July, Available at: [http://www.rightdiagnosis.com/t/turner_syndrome/stats-country.htm]
[3] Joanne F Rovert, Journal of Learning Disabilities, The Psychoeducational characteristics of Children with Turner Syndrome. 1993 vol 5, pg 333-341. Accessed on 13rd July 2014, Available at: [http://www.ncbi.nlm.nih.gov/pubmed/8492052].
[4] State Government of Victoria. (2012). Turner's Syndrome. Available: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Turner's_syndrome. Last accessed 12th August 2014.
[5] Bright Hub. (2014). Chromosomes: Their Structure, Function, and Medical Importance. Available: http://www.brighthub.com/guides/chromosomes.aspx. Last accessed 9th August 2014.
[6] Freeman, H W, U.S National Library of Medicine, National Center of Biotechnology information, An Introduction to Genetic Analysis, 2000. Accessed on 23rd July 2014. Available at: [http://www.ncbi.nlm.nih.gov/books/NBK21870/].
[7] Health Grades Inc, Right Diagnosis from Health Grades, Statistics by country for Turner Syndrome, 2014 Accessed on 23rd July, Available at: [http://www.rightdiagnosis.com/t/turner_syndrome/stats-country.htm]
[2] Health Grades Inc, Right Diagnosis from Health Grades, Statistics by country for Turner Syndrome, 2014 Accessed on 23rd July, Available at: [http://www.rightdiagnosis.com/t/turner_syndrome/stats-country.htm]
[3] Joanne F Rovert, Journal of Learning Disabilities, The Psychoeducational characteristics of Children with Turner Syndrome. 1993 vol 5, pg 333-341. Accessed on 13rd July 2014, Available at: [http://www.ncbi.nlm.nih.gov/pubmed/8492052].
[4] State Government of Victoria. (2012). Turner's Syndrome. Available: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Turner's_syndrome. Last accessed 12th August 2014.
[5] Bright Hub. (2014). Chromosomes: Their Structure, Function, and Medical Importance. Available: http://www.brighthub.com/guides/chromosomes.aspx. Last accessed 9th August 2014.
[6] Freeman, H W, U.S National Library of Medicine, National Center of Biotechnology information, An Introduction to Genetic Analysis, 2000. Accessed on 23rd July 2014. Available at: [http://www.ncbi.nlm.nih.gov/books/NBK21870/].
[7] Health Grades Inc, Right Diagnosis from Health Grades, Statistics by country for Turner Syndrome, 2014 Accessed on 23rd July, Available at: [http://www.rightdiagnosis.com/t/turner_syndrome/stats-country.htm]