Human Chromosome Disorders

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Human Chromosome Disorders
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KaryotypeMap of Human Chromosomes
Homologue
Homologue
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(No Transcript)
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Chromosome disorders

• Sometimes meiosis goes wrong
• Most of the time, the pregnancy ends naturally
  because most chromosome disorders are lethal
• Extra chromosome trisomy

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21 trisomy Downs Syndrome
Can you see the extra 21st chromosome? Is this
person male or female?
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Downs syndrome

• A flattened appearance to the face An upward
  slant to the eyes
• Short neck, arms and legs Intellectual
  disability
• Extra friendly and outgoing

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Edwards syndrome-trisomy 18

• Clenched hands
• Crossed legs
• Feet with a rounded bottom (rocker-bottom feet)
• Mental deficiency
• Small head

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Patau syndrome

• Trisomy 13

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Turners syndromethe only case of missing a
chromosome that can be survived

• Females who are XO instead of XX
• Stocky appearance, arms that turn out slightly at
  the elbow, a receding lower jaw, a short webbed
  neck.
• Other medical symptoms include heart and/or
  kidney defects, high blood pressure, and
  infertility (inability to have children).

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What if a karyotype showed you would have a child
with a chromosomal abnormality?

• What would you do?