Xeroderma pigmentosum

1
Xeroderma pigmentosum

• Kristen Sena
• Calvin Frauenfelder

2
Genotypes

• Since XP is recessive, either parent could
  display the trait or have the unexpressed gene.
  Both of the parents however have to have the
  recessive trait to have a child with the disease.
  
• The genotypes could be Rr X Rr or Rr X rr or rr X
  rr

3
The Odds

• If one of the parents has the disease and the
  other is a recessive carrier then the odds of a
  child getting the disease is 50
• If neither parent displays the gene but carries
  it recessively then the odds of having a child
  that has the disease is 25
• If both parents have the disease the odds of them
  having a child with the disease is 100

4
Life Expectancy and Treatment

• Life Expectancy Less than 40 of patients
  survive beyond the age of 20. Individuals who
  have a milder case of the disease can survive
  past middle age
• Treatment reduce exposure to the sun The number
  of keratoses can be reduced with
  Isotretinoin.Existing keratoses can be treated
  using cryxotherapy or fluorouracil

5
New Treatment

• Gene therapy for the DNA repair disease- the
  construction of a new retroviral container
  containing one of the DNA repair genes known as
  ERCC2. This vector will be used to modify
  keratinocytes to produce repaired skin for graft
  at the worst areas. This study represents the
  first step toward long-term skin cancer therapy
  for XP patients.

6
How do People get it?

• XP is a genetic disease that is inherited from
  the parents.
• Because XP is recessive both parents must either
  be heterozygous, homozygous recessive, or a
  combination of the two.

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How Likely are you to Have it?

• It is estimated that XP infects 1 in 250,000
  people world wide.
• About 40 of all diagnosed cases are in Japan

8
How XP is Diagnosed

• XP is diagnosed by a a visual examination of the
  patients skin and eyes, and a full physical.
• Because it is hereditary a doctor will also
  check for a family history of XP

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Physical Symptoms

• An extremely severe sun burn after a short sun
  exposure (Usually after a childs first sun
  exposure).
• Thick skin.
• A child may develop freckles at an early age.
• Pre-mature aging of skin.
• Oozing raw skin surface.
• Skin cancers.