Xeroderma Pigmentosum Case Study

As I was reading the book for my genetics class, I was amazed of how DNA replication works. DNA replication is the process which copies the DNA in a cell, which then creates two daughter cells. The process is important because it replaces damaged or dead cells. Ineffective protection from the damage can produce a genetic instability causing mutations. DNA replication plays an important role in our body to stay healthy and avoid getting many diseases. Defects in DNA repair can result to many rare hereditary diseases. According to Pierce (2013), defects in DNA repair can cause mutation resulting to diseases associated with cancer. For this assignment I chose the human DNA-repair disease called Xeroderma Pigmentosum.

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This also includes freckle like spots on the skin and predisposition to skin cancer (Pierce, 2013). Skin abnormalities can be seen in XP such as: hyperpigmentation, hypopigmentation, excessive scarring, and skin lesions (telangiectasias). Affected children with XP will have severe sunburn after few minutes in the sun, then that sunburn will turn into blisters that will lasts for weeks. People affected by xeroderma pigmentosum have an increased risk of skin cancer. In other cases, dwarfism, delayed development, mental retardation, and neurological impairment may occur in xeroderma pigmentosum.

The relationship between xeroderma pigmentosum and mutation was discovered when the genes responsible for DNA repair is impaired. DNA repair normally reject many mutations that arises in XP. Research findings discovered that the cells with defective DNA repair are likely to retain mutation than a normal cell; this also includes mutations in genes that regulate cell division (Pierce, 2013). Due to the mutation of the POLH, XPC, and ERCC2 genes, the DNA that was damaged from the sun and toxic chemicals are not repaired. This as a result will lead to cell malfunction and ultimately will become a

According to Pierce (2013), transcription is the process where all cellular RNAs are synthesized from DNA template and translation is the process of translating the sequence of mRNA during protein synthesis. Mutation can affect transcription and translation, because it changes the genetic sequence and and protein structure. Mutation affects transcription because it changes the amino acid sequence and destroys the protein function. Likewise, mutation affects translation because it intervenes the process of mRNA translation and the cellular components that control them (Scheper, Van der Knaap, & Proud, 2007) . As a result, disorders arises when mutations alters the transcription and translation process. Likewise, xeroderma pigmentation is a result of mutation in genes that are responsible for repairing the damaged cells (Genetic Home Reference, 2015). In normal cells, the DNA that is damaged by toxic chemicals and UV rays are fixed before it causes problems. This is not the case for XP; build up of unrepaired damaged cells can lead to the symptoms of xeroderma