Frequently Asked Questions
1. Which doctor should one consult to rule out Xeroderma pigmentosum?Normally parents would consult the GP or family physician for skin or eye problems, who may then refer them to a dermatologist (skin specialist) and / or eye specialist for further workup and management.
2. Why are multidisciplinary clinics necessary for Xeroderma pigmentosum?
XP affects many organs including the skin, eyes and brain and maybe associated with learning difficulties and psychological issues. To address these under one roof, multidisciplinary clinics will be helpful.
In fact, multidisciplinary clinics have been established in the UK and USA - XP patients are seen by specialists in dermatology, neurology, ophthalmology, psychology, nursing specialists and genetic specialists. These clinics are open to anyone diagnosed with XP or with a possible diagnosis of XP.
3. What is the unscheduled DNA synthesis test (UDS) test?
It is the most common test performed in XD to detect defective DNA repair and is performed in cultured skin fibroblasts.
In normal cells, after the defective DNA has been removed, an area of newly-synthesised DNA replaces the damaged section. This repaired DNA has some different features from synthesis of DNA during normal cell division and the former is therefore referred to as unscheduled DNA synthesis or UDS.
In XP the level of UDS is reduced since cellular DNA repair mechanisms are affected.
4. How is UDS measured?
UDS can be measured by autoradiography or liquid scintillation counting, or more recently using a fluorescence assay. A reduced UDS level confirms the diagnosis of XP.
5. What are the types of skin cancers commonly occurring in XP?
Basal cell carcinoma, squamous cell carcinoma and melanoma are skin cancers that occur commonly in persons with XP
6. How are skin cancers that may be detected at an early stage in Xeroderma pigmentosum treated?
Early stage skin cancer is treated by removal of the cancer by surgery, freezing, or use of an electric needle. Depending on the size, type, and location of the cancer, a small cancerous growth can usually be treated in a doctor’s clinic. Large tumors may require extensive surgery to remove large areas of involved skin (dermabrasion) and skin grafting. X-ray treatment has also been employed safely. Precancerous lesions such as solar keratoses, may be frozen with liquid nitrogen.
7. What is the outlook for a child diagnosed with Xeroderma pigmentosum?
For individuals without neurological abnormalities, an early diagnosis and following stringent protection measures as described above yields a good prognosis. They will usually have a relatively normal lifespan, but it is obviously essential to maintain a high level of protection throughout their lives.
In persons with neurological abnormalities, these are usually progressive with worsening disability and depending on their severity, may result in a reduced lifespan.
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8. What are the chances of having another child with XP?
There is a 25 percent (1 in 4) chance that another child having the same parents as that of an earlier affected child will also have XP. Prenatal diagnosis is not done routinely for XP. Patients having a child with XP should seek genetic counseling before deciding to have another child.
9. Can someone suffering from XP have children?
If sexual development is not affected a person with XP can have children. However the decision to have children would depend on the person’s capacity to care for a family and possibly even an affected child.
10. What are some of the latest research being done in XP?
- Lot of research on XP focuses on the etiology of the neurological problems associated with the disorder in some individuals. Answers to this would hopefully give rise to treatments to reduce the neurological degeneration.
- Scientists are studying the genes associated with XP to determine the various functions they may perform.
- A cream containing a DNA repair enzyme is presently being evaluated.
- Other studies include clinical trials on preventing skin cancer with oral medications (isotretinoin, a vitamin A derivative) and evaluating patients with unusual manifestations that is being conducted at the National Institutes of Health.
