Turner Syndrome

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Turner Syndrome

• By Chuan Tran

SBI3U
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Definition

• Chromosomal disorder affecting females
• one of the two x chromosomes is defective or
  completely absent

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History

• Named after a U.S. physician Henry H. Turner
  (born 1892)
• First identified as a disorder in 1928
• First described features in 1930s

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Information

• 1/2500 live female births
• 99 spontaneously abort during first trimester of
  pregnancy
• More common to miscarriage
• Other names monosomy x, TS, Turners syndrome,
  Ullrich-Turner Syndrome, 45,X, Gonadal Dysgenesis
• Rare to occur in more than one child in the same
  family

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Causes

• Genetic disorder
• Chromosome defect
• Chromosomes in the nucleus of every cell that
  contain genetic information necessary to direct
  growth, normal function of systems and cells in
  the body
• Normal human contains 46 chromosomes in each cell

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• 2 of 46 that determine gender
• In females XX
• Males XY
• TS patients are born with 45, with a missing X or
  structurally altered

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Forms of Turner Syndrome

• Monosomy X
• Mosaic

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Monosomy X

• accident in the division of sex chromosomes
  (nondisjunction)
• Patients have only one X chromosome in each body
  cell
• 60 of patients have Monosomy X

This girl has Monosomy
x http//medgen.genetics.utah.edu/photographs/dise
ases/high/611.gif
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Mosaic

• Absent X chromosomes only in some body cells
• Accident during cell division
• Some cells have XX and some have X
• Both forms are not inherited

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Symptoms

• Small stature
• Infertility
• Low posterior hairline
• Low set ears
• Broad chest
• Webbing of the neck
• Wide spread nipples

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• Puffy Feet/Hands
• Arms turned out at the elbows
• Slight droop to eyes
• Scoliosis
• Slight breast development

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Some symptoms shown on this baby that has Turner
Syndrome http//www.lucinafoundation.org/assets/tu
rner-syndrome.jpg
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Effects

• Delayed growth
• Increased incidence of fractures, chance of
  diabetes and heart diseases/defects
• Some learning disabilities (vary among
  individuals)
• Cardiovascular malformations
• Verbal IQ is higher than non-verbal IQ

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• Juvenile arthritis
• Rarely mature without hormone treatment
• Fertility cannot be restored
• Urinary tract malformations (kidney problems)
• Normal menstrual periods do not occur

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Diagnosis

• Prenatal diagnosis
• Ultra sound
• Kidneys and reproductive organs
• Alpha-fetoprotein
• Amniocentesis
• MRI of the chest
• Pelvic exam
• No significant relation between mothers age and
  turner syndrome

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• Genetic analysis of chromosomes
• Chromosome count in white blood cells for
  abnormalities
• Karyotype
• Normal 46,XX or XY
• TS 45,X

http//www.childrensdayton.org/images/turners.gif
This karyotype has a total of 45 chromosomes and
it is missing an X chromosome.
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Treatment

• Female hormone therapy to promote development of
  secondary sexual characteristics and menstruation
• Aortic dissection
• Reproductive technology have also been used to
  help woman with TS become pregnant with a donar
  egg
• Plastic surgery to current webbing of the neck

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Future Outlooks/Research

• Capable of marriage
• Raise a family through adoption
• When carefully monitored they are able to have
  normal life expectancies
• Normal intelligence
• Full productive lives
• No known way to prevent TS

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Bibliography

• Griffith, Andrew. (2005). Turner Syndrome The
  basics. Retrieved on May 14, 2009, from
  http//www.turnersyndrome.org/index.php?optionco
  m_contenttaskviewid40Itemid57
• James Wynbrandt (1991). Genetic Disorders and
  Birth defects. New York Facts on file, Inc.
• ____. (may 2008). Turner Syndrome. Retrieved on
  May 13, 2009, from http//ghr.nlm.nih.gov/conditi
  onturnersyndrome
• Narins, Brigham. (2001). Turner Syndrome. The
  Gale Encyclopaedia of genetic disorders (vol. 2,
  pp 1297 1300). Farmington Hills Thomson Gale.
• Peirce, Benjamin A. (1950). The family Genetic
  Source book. Canada John Wiley Sons, Inc.
• ____. (September 26, 2007). Turner Syndrome.
  Retreived on May 14, 2009, from
  http//www.nlm.nih.gov/medlineplus/ency/article/0
  00379.htm