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| TURNER'S SYNDROME BY TINA HUTCHINSON |
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ABSTRACT
Turner’s syndrome is a chromosomal abnormality in female patients. Diagnosis is usually made by amniocentesis under ultrasound. The development of the patients is stunted. These patients usually need assistants in development.
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KEY WORDS
Turner’s, Turner’s Syndrome, Monosomy X, 45X |
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| Turner’s syndrome is a chromosome abnormality in which a female is born with a missing or misshapen X chromosome. This missing chromosome affects the physical and sexual development. This abnormality occurs during fertilization, when one X chromosome from either the mother or father becomes lost. This paper will explain to you how a missing chromosome affects physical, mental, and developmental problems of Turner syndrome patients. (1) |
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| Turner’s syndrome has first thought of by a Dr. Henry Turner, an internist from the University of Oklahoma who identified a set of common physical features in seven of his patients. The chromosomal deficiency that now defines Turner’s syndrome wasn't discovered until 1959, when the technology to perform karyotypes became available. (2) Chromosomes are structures in the nucleus of every cell in the human body that contain the genetic information necessary to direct the growth and normal functioning of all cells and systems of the body. A normal individual has a total of 46 chromosomes in each cell, two of which are responsible for determining gender. (3) The exact location of the genes on the X-chromosome involved in Turner’s syndrome has not been determined as of 2001. Other names for Turner’s syndrome include monosomy X, 45X, and ullrich-turner syndrome. (1) |
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| CYSTIC HYGROMA |
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Turner's syndrome is the most common sex chromosome abnormality of human females. Its incidence in newborns is approximately 1 in 2,000-3,000. (4) Of these, the majority (99%) spontaneously abort, usually during the first trimester of pregnancy. Advanced maternal age does not seem to be a risk factor by itself for this disorder. |
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| WEB NECK |
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Turner's syndrome is commonly diagnosed prenatal, often in women undergoing amniocentesis or chorionic villus sampling for other reasons. Ultrasonography is a valuable tool for detecting fetuses with Turner's syndrome. Typical findings include a thickened neck, edema of the hands and feet, renal abnormalities, or left-side cardiac abnormalities. The most common abnormality found on ultrasound is a cystic hygroma Presumptive diagnosis by ultrasound should be confirmed by chromosomal analysis. This can be done prior to birth. (5) However, the predictive value of amniocentesis in diagnosing Turner’s syndrome varies from 21-67%. (3) After birth Turner’s syndrome can be determined by clinical history, physical examination, psychological, and educational assessment, blood tests, chromosome analysis, and genetic tests. Girls with several of the characteristic features such as a wide chest with broadly spaced nipples, extra skin ('webbing') on the neck, puffy hands and feet, inability to straighten the elbow joints, pigmented moles, soft upturned nails, and low hairline may be diagnosed during infancy or early in childhood. Girls without any of the obvious features may not come to a doctor's attention until they or their parents express concern about poor growth or lack of sexual development. More then 95% of women with Turner’s have short stature and infertility. (6) All girls who are very short for their age or grow less than two inches a year should see a doctor. (7) |
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| Most women with Turner’s syndrome can live relatively normal lives. The prognosis for a person with Turner’s syndrome is dependent on other conditions that may be present. Care must be taken to regularly monitor them for the health problems that are associated with Turner’s syndrome. (3) The most significant features of Turner's syndrome include. short stature , infertility, absence of menstruation, congenital heart defects in about 50 per cent of affected women, spatial awareness issues, and hearing problems. (6) |
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| Because only one X chromosome is present, the ovaries do not develop normally, do not function fully and have a lower volume. This means that they do not produce adequate amounts of female hormones, so the young teenager will not go through puberty (develop breasts and menstruate) unless hormones are provided. When the child is about 3 to 5 years old, the doctor may recommend growth hormone treatment to increase final adult height. When she is about 12 or 13 she will begin taking female sex hormones estrogen and progesterone in pill form to stimulate her sexual development. She must continue taking these hormones until at least the age of menopause. (1) Only the ovaries are affected; the uterus (womb) and vagina are normal, so adult sexual function is unaffected. Pubic and axillary hair may grow normal. Having undeveloped ovaries also means that the woman is quite likely to be infertile, however there are rare cases of women with Turner’s syndrome conceiving children. The missing or abnormal chromosome does not mean that girls with Turner’s syndrome are not really female; they are women with a condition that causes poorly developed ovaries and short stature. (7) Small streaks of gonadal tissue may form in the place of the ovaries and are at risk to become cancerous over time. (4) |
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| FETAL LIMB DEFECT |
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Although a few women may reach or exceed 5 feet in height, girls with Turner’s syndrome are shorter than their peers and reach an average adult height of 4 feet 8 inches. Their body proportions are normal. Some affected girls have excess skin folds around the neck and puffy hands and feet at birth. This puffiness often disappears during infancy and the extra neck skin becomes less noticeable. Girls with this syndrome may have many middle ear infections during childhood. If not treated, these chronic infections could cause hearing loss or deafness. (7) They may also develop nerve deafness caused by degeneration in the hearing nerves. Middle ear infections in girls with Turner’s syndrome are more vulnerable to ear infections because their ear tubes are narrower than normal. Kidney, heart, thyroid and skeletal problems are more common in females with Turner syndrome than in the rest of the population. Congenital heart defects occur because the various structures of the heart may fail to develop normally in utero. While some of the affects can be corrected themselves, others need surgery. High blood pressure occurs more commonly in teenage and adult women with Turner's syndrome. It may be caused by a narrowing of the aorta. Kidney abnormalities are present in 25 to 30% of girls with Turner’s syndrome and may not be detected until kidney damage has occurred. There is also a higher rate of Type II diabetes and thyroid gland disorders in women with Turner's syndrome. (6) Few women with Turner’s syndrome exhibit all of these features. Some have only undeveloped ovaries and short stature, with none of the other physical findings or problems. |
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| Despite such claims in older medical textbooks mental retardation is not a feature of Turner syndrome. Thorough psychological studies show that these women are normal intellectually, but often have a characteristic pattern of intellectual functioning. Their non-verbal IQ may be considerably lower because of problems visualizing objects in relation to each other. This difficulty may show up in poor performance in math, geometry, and tasks requiring manual dexterity or sense of direction. It is important to have psychological testing performed promptly if school problems arise. Some experts suggest that all girls with Turner’s syndrome have this testing done in the early grades in school, so that teachers can pay special attention to helping the girl compensate for any problems that exist. (7) |
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| Turner’s syndrome only affects women except in rare occasions. The exception is found in boys who combine 45,X cells and 46,XY cells. So, they have characteristic male cells (those which are 46,XY) but they also have typical Turner’s syndrome cells (45,X). The form is called mosaic Turner ’s syndrome. Roughly half of the females with Turner's syndrome have X chromosome monosomy (45, X). Most of the other individuals are mosaics, having varying fractions of cells with other chromosome complements (e.g. 45,X/46,XX). In roughly two-thirds of cases having a 45,X karyotype, the single X chromosome is of maternal origin. (5) It is estimated that 3-8% of girls with a single X-chromosome and 12-21% of females with sex chromosome mosaicism may have normal pubertal development and spontaneous menstrual periods. (3) |
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Turner's syndrome is a lifelong random genetic disorder. However, many treatment options are available to help affected girls and women reach their potential in all aspects of life. If a girl with Turner syndrome and her parents obtain good medical and psychological care, the chances for a satisfying, happy and healthy life are excellent.
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1. Turner’s Syndrome, American Medical Association- Family Medical
Guide 4th ED, 2004, ISBN 0-471-26911-5
2. Turner’s Syndrome Society oh the US - Turner’s syndrome
http://www.turner-syndrome-us.org/resource/faq.html
3. healthAtoZ- Turner’s syndrome Source: Gale Encyclopedia of Medicine, Published December, 2002 by the Gale Group, The Essay Author is L. Fleming Fallon MD, PhD, DrPH. http://www.healthatoz.com/healthatoz/Atoz/ency/turner_syndrome.jsp
4. Turner’s Syndrome, American Medical Association –Comp Medical
Encycopedia 1st ED, 2003, ISBN 0-8129-9100-1
5. Turner’s Syndrome (X Monosomy, Gonadal Dysdenesis) Last update Sept
18, 2004 http://arbl.cvmbs.colostate.edu/hbooks/genetics/medgen/chromo_eg/turners.html
6. BetterHealth Vitorian Turners Association – Turner’s Syndrome
Article publication date: 02/10/2003 Last reviewed: October
2004 http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Turner's_syndrome?Open
7. Human Growth Foundation- Turner’s syndrome Last update Sept 18,2004 http://www.hgfound.org/turner.html |
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