Xeroderma Pigmentosum Research Paper

Superior Essays
Xeroderma Pigmentosum (XP) is an inherited recessive disease, this means two recessive alleles are present in an individual from their parents. This disease impairs the ability of the body to repair DNA which is damaged mainly by Ultraviolent light as well as various chemical Carcinogens. ” The most common forms of DNA damage occurs via the cross linking of adjacent pyrimidines resulting in the formation of cyclobutane pyrimidine dimers (CPDs)” (1) for example UV light will often make two T 's bases next to each other bind making a dimer.

The regions of the cells that are affected by the disease are called the nucleotide excision repair (NER) enzymes. There are two types of NER that exist: global genome (GG-NER) and transcription coupled
…show more content…
The XPA gene is responsible for providing instructions for making proteins that are involved in repairing damaged DNA. XPB has the same type of mutation as XPA however it is an essential subunit of a 9 unit general transcription factor IIH (TFIIH) complex. The TFIIH complex helps repair damaged DNA therefore mutation in XPB means the TFIIH complex doesn’t form properly hence cannot do its job. In XPC there is a single base substitution on the third chromosome this causes a missense mutation which produces inactivated XPC protein this is crucial because XPC proteins start NER process by detecting DNA damage in the GG-NER pathway. Therefore without the XPC protein DNA repair process cannot be started as the damaged DNA isn’t identified by the body. The XPD gene is found on chromosome 19. XPD is involved with working with the XPB gene to form TFIIH complex. TFIIH is involved in the regulation of transcription of active genes, as well as in NER (4)(5). Therefore if the TFIIH complex does not form correctly this could possibly alter the rate of transcription for example, increasing it which would cause exponential cell growth and this could be a reason why people who have XP are much more like to develop cancer. XPV is a variant of XP and does not affect NER. Instead, there is a defect in DNA polymerase which alters post …show more content…
There a few different theories as to how neurodegeneration occurs such as due to the lack of an effective NER pathway the mutations in “DNA can have effects on post-mitotic neurons and cause severe CNS symptoms” (4) and “It is most likely that there are some forms of oxidative damage for which NER is also the repair pathway, just as there are likely to be other forms where resolution will involve DNA strand break repair” (9). However the exact process of how neurodegeneration occurs is still unknown. The key variations of XP that cause neurodegeneration are XPA, XPD and XPG , which XPG having the most severe effect. Some neurological problems that occur from XP are loss of hearing, hyporeflexia, progressive mental retardation, poor co-ordination and seizures.
There are several ways to suppress the symptoms of XP such as to limit exposure to direct sunlight, however if this is not possible then, the use of sunscreens with a SPF of 15 or greater and other sun-avoidance methods e.g., protective clothing can minimize UV damage. Cryosurgery is the use of liquid nitrogen to freeze cancer cells, which kills the cancer cell however this can only be used to treat cancers that are not large or deep. Conventional treatments can also be used such as chemotherapy and Mohs surgery

Related Documents

  • Superior Essays

    The genetic information in an organism’s DNA ultimately determines its traits; however, if this genetic information is somehow altered (the arrangement of nucleotides changed) new traits can appear or a deformity might occur. When a cell fails to replicate properly and DNA that is produced is not identical to that of the original (as a result of changes made for various reasons), a mutation has occurred. Failures in replication can be caused by a large number of reasons, but some of the more common examples include incorrect pairing of nitrogen bases and exposure to radiation and certain chemicals. “A mutagen is any agent that changes the DNA of an organism.” An example of a mutagen is a virus because viruses injects their genetic information…

    • 876 Words
    • 4 Pages
    Superior Essays
  • Superior Essays

    Common cancers Topoisomerase inhibitor drugs treat are leukemia, lung, and ovarian cancers. A disadvantage to taking Topoisomerase inhibitor drugs is that there is a greater chance of being diagnosed with a second cancer. Mitotic inhibitor drugs are plant alkaloids that come from natural products and work by stopping mitosis or enzymes from making the proteins that the cancer cell would need to produce more. This drug treatment works during the m cycle of the cell phase. Two side effects from Mitotic inhibitor drugs are that it can harm cells in all stages of the cell…

    • 1072 Words
    • 5 Pages
    Superior Essays
  • Improved Essays

    Heterogeneity Of Cancer

    • 834 Words
    • 4 Pages

    It was interesting that there is precancerous cells which does not spread around the body tissues but may become invasive. Also, it was surprising that the technology is so developed that scientists now can analyze every single cancer cell not average of them. Furthermore, just like other organisms, the more genetically diverse cancer cells, the higher chance to survive in changing environments. I would like to introduce this article to classmates because this article might be helpful to give some idea that how our current cancer research is improved and know about precancerous and cancer cell research. It will be long way to go; however, we are able to find treatment and cure the cancer completely…

    • 834 Words
    • 4 Pages
    Improved Essays
  • Superior Essays

    The Cause Of Cancer

    • 1239 Words
    • 5 Pages

    A body is made up of cells, and in each cell, genes are found. Genes are passed down to children from parents, and over time genes can mutate. Mutations, or changes, in genes acquired from a mother or father, or genes damaged throughout a person’s life, is what contributes to the growth and development of cancer. Normally, one mutation will not cause cancer because the human body can correct that change, but with a multitude of mutations over time cancer becomes more probable. There have also been studies on how the loss of a sex chromosome will lead to the likeliness of cancer in males.…

    • 1239 Words
    • 5 Pages
    Superior Essays
  • Great Essays

    Gene Therapy & Cancer Cells Gene therapy is often defined as a treatment that uses genes to cure or prevent diseases. Genes, DNA, and protein are all involved with each other, therefore, in many immune diseases, if one fails your whole immune system could eventually fail. This treatment is relatively new; hence it is still a pretty risky experimentation since it involves getting genes into cancer cells. Gene Therapy is often involved in serious cancer cell treatments; its main purpose is to try to trick the immune system into believing that the cancer cells are foreign. This type of therapy is only used in certain conditions such as if there is not another option.…

    • 1271 Words
    • 6 Pages
    Great Essays
  • Great Essays

    The human genome has thousands of different types that are usually found in human’s genes and mammals. One of the most important is microRNA-34a. It acts as a regulator of the suppression of tumors in the human body. When cancer is present, transcription factors are not able to bind with the double helix strand because the exact sequence required is not present due to a mutation in the DNA strand. MicroRNA 34a plays the role of the transcription factor that was supposed to stick.…

    • 2340 Words
    • 10 Pages
    Great Essays
  • Improved Essays

    Gene Editing Ethics

    • 1350 Words
    • 6 Pages

    Although CRISPER/CAS 9 is often precise, it has been known to cut the wrong strand of DNA leading to a whole new problem. The main subject of debate is whether or not to allow germ-line gene editing. Germ line editing is altering the genome in the sperm or egg cell. This provides the ability to change the genetics that a child is born with and these change s traits that would be inherited further down the generations. In altering the inherited traits we may be causing more problems in future generations while correcting the current ones.…

    • 1350 Words
    • 6 Pages
    Improved Essays
  • Improved Essays

    (1) The molecules in cancer cells decide whether a cell should repair itself or not .EX: “a protein called p53 normally checks to see if the genes can be repaired or whether the cell should die”, so basically it decides to repair itself. But many cancers have a wrong machine version of p53, so they don't repair themselves properly.Cancer cells don't repair themselves or die. (1) Even a single mistake at the process of repairing themselves,can lead to problems…

    • 853 Words
    • 4 Pages
    Improved Essays
  • Improved Essays

    The first changes in the genes (DNA) inside the lung cells may cause the cells to grow faster. These cells may look a bit abnormal if seen under a microscope, but at this…

    • 1055 Words
    • 4 Pages
    Improved Essays
  • Improved Essays

    Each individual’s epigenome become unique as it changes over time due to factors such as diet, stress, physical activity, and toxin exposure. The MGMT gene can be activated or inactivated by epigenetics. This gene is located on the chromosome 10q26 and encodes for a DNA repair enzyme (6). If this gene is left unmethylated, it is active and is able to repair damaged cells. This function is counterproductive during chemotherapy with the use of temozolamide because the drug damages the DNA and tries to kill cancer cells, but the MGMT works to repair these unwanted cells.…

    • 783 Words
    • 4 Pages
    Improved Essays