Xeroderma pigmentosum

Definition

Xeroderma pigmentosum is a rare genetic disorder characterized by extreme sensitivity to ultraviolet (UV) radiation, leading to skin damage and a significantly increased risk of skin cancers. This condition arises from defects in the DNA repair mechanisms, specifically in nucleotide excision repair pathways that are crucial for correcting UV-induced DNA lesions. People with this disorder often exhibit symptoms such as sunburns after minimal sun exposure, freckling, and a higher propensity for skin malignancies.

5 Must Know Facts For Your Next Test

1. Individuals with xeroderma pigmentosum have a mutation in one of several genes responsible for the nucleotide excision repair pathway, which impairs their ability to fix UV-induced DNA damage.
2. There are eight different complementation groups of xeroderma pigmentosum, each associated with mutations in different genes related to DNA repair.
3. Symptoms of xeroderma pigmentosum typically appear in childhood, often beginning with severe sunburns after sun exposure.
4. Due to the impaired DNA repair mechanisms, those with this condition can develop skin cancers at a much younger age compared to the general population.
5. Management of xeroderma pigmentosum includes strict sun protection measures, regular skin examinations, and possible surgical interventions for any skin cancers that develop.

Review Questions

• How does the deficiency in nucleotide excision repair contribute to the symptoms observed in individuals with xeroderma pigmentosum?
  • The deficiency in nucleotide excision repair in individuals with xeroderma pigmentosum leads to an inability to effectively remove and repair UV-induced DNA lesions. This results in cumulative damage from sun exposure, manifesting as severe sunburns, freckling, and early onset of skin cancers. Since these individuals cannot properly repair the DNA damage caused by ultraviolet radiation, their skin cells are more likely to undergo malignant transformation.
• Discuss the implications of xeroderma pigmentosum on the long-term health and lifestyle choices of affected individuals.
  • Individuals with xeroderma pigmentosum face significant long-term health challenges due to their heightened risk of developing skin cancers. This necessitates rigorous lifestyle adaptations, such as avoiding direct sunlight, wearing protective clothing, and applying high-SPF sunscreen even on cloudy days. Regular dermatological check-ups become crucial for early detection of any cancerous changes, fundamentally altering how they engage with outdoor activities and social interactions.
• Evaluate the broader societal impact of xeroderma pigmentosum regarding genetic counseling and public awareness about genetic disorders.
  • The existence of xeroderma pigmentosum highlights the importance of genetic counseling and public awareness regarding genetic disorders. As this condition is inherited in an autosomal recessive manner, understanding its genetic basis allows families to make informed decisions about reproduction and management. Additionally, raising awareness about the need for sun protection and early skin cancer screening can lead to better health outcomes for affected individuals, ultimately reducing the burden on healthcare systems associated with advanced skin cancers that could have been prevented through early intervention.

Related terms

Nucleotide Excision Repair: A DNA repair mechanism that removes damaged DNA sections and replaces them with the correct sequence, essential for repairing UV-induced damage.

Ultraviolet Radiation: A type of electromagnetic radiation that can cause direct DNA damage and is a major environmental factor contributing to skin cancer.

Basal Cell Carcinoma: The most common type of skin cancer often seen in individuals with xeroderma pigmentosum due to their increased sensitivity to UV light.