BIOL355 Lecture Notes - Lecture 17: Xeroderma Pigmentosum, Pyrimidine Dimer, Melanoma
3 Feb 2016
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Document Summary
Usually base excision repair replacement of dna w/ new bases seal of gap w/ dna ligase the way that 8-hydroxyguanine is removed. Repair of thymine dimers leads to an risk in xeroderma. Pigmentosum sunlight on children leads to inflammation and blistering skin is dry. Moles increase skin cancer at age 13. Evidence of xeroderma pigmentosum would imply that decrease in repair -> increase disease such as cancer. Skin cancer represents the major morbidity in xeroderma pigmentosum. The median age of the first cutaneous cancer in xeroderma pigmentosum (most commonly basal cell or squamous cell carcinoma) is 8 years. In striking contrast, the mean age for squamous cell carcinoma in the general population is 58 years. The incidence of malignant melanoma in patients with xeroderma pigmentosum who are younger than 20 years is 2000- fold higher than in an age-matched us population. Skin tumors are typically multiple, and patients with as many as.
