The present status of xeroderma pigmentosum in Japan and a tentative severity classification scale

Abstract

Xeroderma pigmentosum (XP) is a rare autosomal recessive hereditary disease.Patients with XP have severe hypersensitivity to sunlight, resulting in skin cancers, and some patients have neurological symptoms. In Japan, XP complementation group A (XP-A) is the most common form, and it is associated with severe neurological symptoms. We performed a nationwide survey on XP to determine the present status of XP in Japan. The distribution of complementation groups in Japan was considerably different from that in other countries, but there was a higher frequency in group A and the variant type, which is similar to previous reports in Japan. Basal cell carcinoma was the most frequent skin cancer that patients with XP developed, followed by squamous cell carcinoma and malignant melanoma. The frequency of these skin cancers in patients with XP-A has decreased, and these skin cancers have been occurring in much older people than those previously observed. Diagnosing XP in patients at younger ages seems to encourage patients and their parents to use sun protection, which helps prevent skin cancer. We also created a tentative scale for classifying the severity of XP, and we evaluated the neurological symptoms of XP-A using this severity scale.Our classification correlated well with patients' age, suggesting that it may be useful and feasible in clinical practice to assess the progression of symptoms of each patient with XP and evaluate the effects of treatment in the future. K E Y W O R D Sepidemiological survey, hereditary disease, neurological symptoms, skin cancer, xeroderma pigmentosum 1

Clinical and genetic characteristics of xeroderma pigmentosum in Nepal

“…Xeroderma pigmentosum has been found worldwide to display a wide clinical and genetic heterogeneity, depending on patients’ phototype, conditions of life and genetic basis . Eight defective proteins encoding by genes located on different chromosomes have been implicated in the disease .…”

Autopsy findings and clinical features of a mild-type xeroderma pigmentosum complementation group A siblings: 40 years of follow-up

“…These patients die at around 20 years, whereas patients with homozygous R228X are known to manifest milder clinical features 5, 6. We compared the progress of our cases' symptoms with that of patients with homozygous IVS3-1G>C by using the XP severity classification scale, wherein the patients' neurologic status in daily living activities, motor function, and cognition are assessed 7, 8. Previously, we found the severity score is well correlated with patients' ages in 49 patients with homozygous IVS3-1G>C mutation of XPA .…”

Characteristics of Xeroderma Pigmentosum in Japan: Lessons From Two Clinical Surveys and Measures for Patient Care

“…In the first survey, all patients who had visited the hospitals once were compiled . In the nationwide XP survey in 2016, patients with probable XP who had visited medical institutions during 2013–2015 were enrolled as previously described . Table shows the frequencies of each of the complementation groups who were enrolled in the 2016 survey.…”

“…The 2016 survey may provide insights regarding the outcomes of strict sun protection. A survey for patients with XP was conducted as previously described . We compared the cancer frequency and age of onset of cancer development between the present results and those of 28 years ago .…”