Prenatal diagnosis: Trisomy 21 (Down

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• karyotype
• picture of the chromosomes in a cell used to
  check for abnormalities

Prenatal diagnosis Trisomy 21 (Downs syndrome)
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• Preparing a karyotype
• harvest cells

• Postnatal diagnostic karyotype
• tumor biopsy
• skin cells from mouth (ie. for non-cancer related
  diagnoses)
• Prenatal diagnostic karyotype
• chorionic villi sampling (CVS)
• amniocentesis

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• Who is offered amniocentesis or CVS?
• maternal age (women 35 or older)
• Risk of Downs syndrome
• mother in 20s 1/1250 99.92 OK
• mother at 35 1/400 99.75 OK
• mother at 40 1/100 99 OK

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Prenatal diagnosis amniocentesis

• sampling cells from amniotic fluid
• usually done 15-18 weeks

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• DiGeorge syndrome/CATCH22
• microdeletion on chromosome 22
• birth defect that affects the immune system
• absence of or underdevelopment of the thymus and
  parathyroid glands
• facial features include low-set ears, wide-set
  eyes, small jaw, and bowing up of upper lip

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EngageGenetic Disorders

• Patau Syndrome
• Edward Syndrome
• Klinfelters Syndrome
• Turner Syndrome
• Super Male Syndrome
• Super Female Syndrome

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47, XX or XY, 13

• serious eye, brain, circulatory defects as well
  as cleft palate. 15000 live births. Children
  rarely live more than a few months.
• Patau Syndrome

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Edward Syndrome

• almost every organ system affected 110,000 live
  births. Children with full Trisomy 18 generally
  do not live more than a few months.

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Turner Syndrome
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Turner Syndrom
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Kleinfelter Disease
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Kleinfelter
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Super Male and Super Female

• - Has an XXX- Fertile females with normal
  intelligence

• Has an XYY- Tall male with heavy acne- Some
  tendency to mental retardation
• Aggressive tendency

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