OBJECTIVE To describe the features of Xeroderma pigmentosum observed in the stage 3 of the disease. STUDY DESIGN Case series. PLACE AND DURATION OF STUDY Mayo Hospital Lahore, from December 2001 to September 2008. METHODOLOGY All patients diagnosed with Xeroderma pigmentosum stage 3 in the outpatient department of the study centre, were included. The age at first presentation, tumour site...

Seven cases of XP seen during a relatively short period of time, possibly indicate a high frequency of this gene in this part of the country. The gene frequency in the general population has been reported to be 1 in 200 million and the frequency of the disorder, 4 in 1 million(3). Countries like Libya, Egypt, Israel and Japan, with a high degree of consanguinity, have a high incidence of this d...

Xeroderma pigmentosum (XP) is defined by extreme sensitivity to sunlight, resulting in sunburn, pigment changes in the skin and a greatly elevated incidence of skin cancers. It is a rare autosomal recessive disorder and has been found in all continents and racial groups. Estimated incidences vary from 1 in 20, 000 in Japan to 1 in 250, 000 in the USA, and approximately 2.3 per million live birt...

We present the case of an eighteen-year-old Caucasian white boy who was diagnosed with xeroderma pigmentosum type A at age 5 and who experienced over the past year disseminated small plaque psoriasis confirmed with skin punch biopsy. The psoriatic lesions were successfully treated with multipotent topical corticosteroids and systemic retinoids. To our knowledge, the association between psoriasi...

We have cloned human xeroderma pigmentosum group A complementing (XPAC) cDNA that encodes a "zinc finger" protein with a predicted size of 31 kDa. To detect the xpac protein in cells, we raised antibody against a recombinant human xpac protein. Using this antibody, we identified the xpac protein in the nucleus of cells. In normal human cells, 40- and 38-kDa proteins were detected by sodium dode...

A shuttle vector plasmid, pZ189, was utilized to assess the types of mutations that cells from a patient with xeroderma pigmentosum, complementation group D, introduce into ultraviolet (UV) damaged, replicating DNA. Patients with xeroderma pigmentosum have clinical and cellular UV hypersensitivity, increased frequency of sun-induced skin cancer, and deficient DNA repair. In comparison to UV-tre...

An assay has been developed in which excision repair deficiency of xeroderma pigmentosum cells is transiently complemented, as measured by unscheduled DNA synthesis, by microinjection of cytoplasmic poly(A)+ RNA derived from HeLa cells. Four different complementation groups of xeroderma pigmentosum have been assayed. Groups A and G showed complementation, whereas groups D and F did not. Surviva...

Oxidative DNA damage, including both mutamente and cytotoxic le sions, is implicated in aging and cancer. Studies of the processes which correct such damage in mammalian cells are, however, still in their early stages. Here we have summarized our recent work which demonstrates new features of mammalian oxidative UNA damage repair, such as (a) a functional role for polylADP-ribosyllation in the ...

Treatment of normal human cells with DNA-damaging agents such as UV light or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stimulates the conversion of NAD to the chromosomal polymer poly(ADP-ribose) which in turn results in a rapid depletion of the cellular NAD pool. We have studied the effect of UV light or MNNG on the NAD pools of seven cell lines of human fibroblasts either homozygous or hete...

Introduction: Xeroderma pigmentosum is an autosomal recessive disease with sun sensitivity, photophobia, early onset of freckling, and subsequent neoplastic changes on sun-exposed surfaces. There is cellular hypersensitivity to UV radiation and to certain chemicals in association with abnormal DNA repair. Patients with defective DNA nucleotide excision repair (NER) have defects in one of seven ...