Xeroderma pigmentosum in Libya

Oral mucosa involvement in pediatric patients with xeroderma pigmentosum: a comprehensive review

BACKGROUND

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder presenting with an inability to repair UV-induced DNA damage. This can lead to the development of neoplasms affecting multiple organ systems, with onset often in childhood. Unfortunately, no cure currently exists for XP, and management strategies focus on sun protection and early intervention for malignancies. Although most skin problems in XP patients are UV induced, various oral lesions are also described. However, the literature has not extensively characterized the oral manifestations and their prognostic significance.

METHODS

We conducted a comprehensive review to evaluate the prevalence and nature of oral mucosal lesions in pediatric XP patients.

RESULTS

Our literature search yielded 130 pediatric XP patients with oral involvement and 210 associated tumoral or non-tumoral lesions. Squamous cell carcinoma was the most common type of oral mucosal tumor reported, with other malignancies including basal cell carcinoma, melanoma, angiosarcoma, fibrosarcoma, and trichilemmal carcinoma.

CONCLUSION

Given the potential morbidity and mortality associated with oral mucosal tumors in XP patients, our study aims to raise awareness of these manifestations. Early diagnosis and treatment are crucial for managing these lesions effectively, and routine oral exams should be considered a critical component of dermatological evaluations for XP patients, especially in the pediatric age group.

Clinical and molecular characterization of Xeroderma pigmentosum in Moroccan population: a case series of 40 patients

Background

Xeroderma pigmentosum (XP) is a rare autosomal recessive skin disorder characterized by hyperpigmentation, premature skin aging, ocular and cutaneous photosensitivity with increased risk of skin tumors. XP is caused by mutations in DNA repair genes that protect cells from UV-induced DNA damage. The current study aims to investigate, on clinical and genetic basis, Moroccan XP patients. We explored by direct sequencing the involvement of the prevalent XPA and XPC genes mutations: nonsense mutation (c.682C>T, p.Arg228X) and a two-base-pair (2 bp) deletion (c.1643 1644delTG or p.Val548Ala fsX25), respectively, in 40 index cases from 37 unrelated families in Moroccan population.

Results

Early skin and ocular manifestations were detected with high rate of malignancy. Cutaneous lesions progressed to malignant skin tumor in 70% of cases. Ocular tumors were also observed in 11 patients including BCC in eight cases, SCC in three cases and melanoma in four cases. Among the 40 patients, there were 20 homozygous cases for the 2 bp deletion in the XPC gene and 9 homozygous cases carrying the nonsense XPA mutation.

Conclusion

These findings obtained in the present study revealed that the XPC gene mutation (c.1643 1644delTG, p.Val548AlafsX25) is the major cause of Xeroderma pigmentosum in our population. The c.682C>T (p.Arg228X) mutation is relatively associated with moderate phenotype in XP group A Moroccan families. This result will also contribute to improving the molecular diagnosis of XP disease and will have a significant impact on improving the care of Moroccan patients and their relatives.

Recurrent squamous cell carcinoma and a novel mutation in a patient with xeroderma pigmentosum: a case report

BACKGROUND

Xeroderma pigmentosum is an extremely serious genetic disorder defined by sensitivity to sunlight, resulting in sunburn and pigment changes. If patients are not completely protected from ultraviolet radiation, xeroderma pigmentosum is characterized by a greatly increased risk of sunlight-induced cutaneous neoplasms. There is no standard therapy for skin cancer of xeroderma pigmentosum. However, immune checkpoint inhibitors were reported to increase response rates and improve outcomes and life expectancy in patients with various cancers, including squamous cell carcinoma in xeroderma pigmentosum. In this paper, we report on a patient with xeroderma pigmentosum from a consanguineous family with recurrent facial chemotherapy-resistant squamous cell carcinoma lesions treated successfully with an anti-programmed cell death protein 1 monoclonal antibody in both relapses.

CASE PRESENTATION

A 7-year-old Turkish male was referred to our oncology department for recurring squamous cell carcinoma after local excision of the tumor over his nose. The lesion was a rapidly growing lesion, measuring 8 × 4 cm in size. Physical examination revealed that he also had hemorrhagic crusted plaques and nodules over both eyelids and upper lip, with multiple hypo- and hyperpigmented punctate lesions all over his body. After two more cycles of chemotherapy, progressive disease was noted, and a new lesion on the right eyelid caused blurred vision. Anti-programmed cell death protein 1 antibody treatment was planned with concomitant radiotherapy. He received nivolumab every 3 weeks for 4 months, improving his vision. No new lesions or active complaints have been observed in the current situation, and complete remission has been achieved. On the last admission, the patient was clinically diagnosed with xeroderma pigmentosum. Owing to the condition's genetic heterogeneity, whole-exome sequencing was performed with Ion Proton next-generation sequencing platform, and the c.2250 + 1G>A splice site mutation of the XPC gene was detected in the homozygous state.

CONCLUSIONS

The clinical report emphasizes the importance of clinical awareness and crucial early diagnosis of xeroderma pigmentosum and presents a novel causative homozygous c.2250 + 1G>A splice site mutation. Our case proves that next-generation sequencing is an effective method for the rapid diagnosis and determination of xeroderma pigmentosum genetic etiology.

Increased risk of internal tumors in DNA repair-deficient xeroderma pigmentosum patients: analysis of four international cohorts

Background

Xeroderma pigmentosum (XP) is a rare, autosomal, recessive DNA repair-deficiency disorder with a frequency of 1–3 per million livebirths in Europe and USA but with higher frequencies in isolated islands or in countries with a high level of consanguinity. XP is characterized by high incidence of skin cancers on sun-exposed sites. Recent improvement in life expectancy of XP patients suggests an increased risk of frequently aggressive and lethal internal tumors. Our purpose was to quantify relative risks of internal tumor development for XP patients by tumor type, XP-subtype, patients’ ages and ethnicity through comparison with the US general population.

Methods

We analyzed four independent international well-characterized XP cohorts (from USA, UK, France and Brazil) with a total of 434 patients, where 11.3% developed internal tumors and compared them to the American general population. We also compiled, through PubMed/Medline, a dataset of 89 internal tumors in XP patients published between 1958 and 2020.

Results

In the combined 4-XP cohort, relative risk of internal tumors was 34 (95% confidence interval (CI) 25–47) times higher than in the general population (p-value = 1.0E−47) and tumor arose 50 years earlier. The XP-C group was at the highest risk for the 0–20 years old-patients (OR = 665; 95% CI 368–1200; p-value = 4.3E−30). The highest risks were observed for tumors of central nervous system (OR = 331; 95% CI 171–641; p-value = 2.4E−20), hematological malignancies (OR = 120; 95% CI 77–186; p-value = 3.7E−36), thyroid (OR = 74; 95% CI 31–179; p-value = 1.2E−8) and gynecological tumors (OR = 91; 95% CI 42–193; p-value = 3.5E−12). The type of mutation on the XPC gene is associated with different classes of internal tumors. The majority of French XP-C patients (80%) are originated from North Africa and carried the XPC delTG founder mutation specific from the South Mediterranean area. The OR is extremely high for young (0–20 years) patients with more than 1300-fold increase for the French XPs carrying the founder mutation.

Conclusion

Because the age of XP population is increasing due to better sun-protection and knowledge of the disease, these results are of particular importance for the physicians to help in early prevention and detection of internal tumors in their XP patients. Few preventive blood analyses or simple medical imaging may help to better detect early cancer appearance in this population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02203-1.

Xeroderma pigmentosum variant: squamous cell carcinoma of the lower lip harboring exon 11 mutation of POLH

Xeroderma pigmentosum (XP) is a rare inherited disease caused by deficiencies in DNA damage repair, which mainly results from the failure of nucleotide excision repair or defects in translesion DNA synthesis. The development of multiple malignancies is one of the most prominent features of this condition, which is clinically characterized by the occurrence of hyperpigmentation and lesions associated with sunlight exposure. Lip squamous cell carcinoma in patients with XP has rarely been reported, and information regarding the genetic analysis of these patients is limited. In this report, a case of a 20-year-old patient who developed squamous cell carcinoma in the lower lip is described. Although the tumor was surgically excised, the patient presented with recurrence a few months later. Targeted sequencing using a customized panel of DNA repair genes revealed a mutation in POLH, the gene encoding DNA polymerase eta. Therefore, molecular characterization is important to further improve the understanding of possible phenotype-genotype correlations and mechanisms involved in the pathogenesis of XP.

Skin tumors in xeroderma pigmentosum: Evaluation of a large series and a literature review

BACKGROUND

Xeroderma pigmentosum (XP) is a rare genodermatosis with a lifelong propensity to develop malignant skin tumors.

METHODS

In this retrospective study, 24 XP patients were evaluated with regard to frequency and clinicopathological features of benign and malignant skin tumors.

RESULTS

Seventeen patients had at least one malignant skin tumor diagnosed: basal cell carcinoma (BCC) in 13 patients (n = 72), basosquamous carcinoma in three patients (n = 4), squamous cell carcinoma in six patients (n = 13), keratoacanthoma in three patients (n = 15), and melanoma in six patients (n = 18). Most melanomas (n = 15) were in situ lesions. Several benign skin tumors were noted such as tricholemmoma (n = 1), trichoepithelioma (n = 1), trichoblastoma (n = 1), follicular infundibulum tumor (n = 1), keratoacanthoma-like follicular lesion (n = 1), adnexal tumors with folliculosebaceous (n = 1) and tricholemmal differentiation (n = 1), and neurofibroma (n = 1). Benign vascular proliferations including pyogenic granulomas (n = 8), widespread telangiectasias, and senile angioma-like lesions were also observed in 3, 5, and 5 patients, respectively.

CONCLUSIONS

Similar to many reports, BCC was found to be the most common malignant skin tumor. The high prevalence of benign adnexal tumors of follicular differentiation, some of them showing mixed histopathological features and various vascular proliferations in our series raises the question of whether they indicate a formerly undescribed association with XP.

Xeroderma pigmentosum in Yemen

BACKGROUND

The incidence of xeroderma pigmentosum (XP) in Yemen seems to be quite high but there are no previous reports.

OBJECTIVE

To study the clinicoepidemiologic aspect of XP in Yemen.

METHODS

All 40 patients (24 male and 16 female patients from 32 families) treated and followed between 1997 and 2014 were subjected to detailed analysis with the help of a standardized protocol. The diagnosis was based on clinical features and histopathologic data, when needed. The diagnosis of tumors was confirmed by histopathologic examination in all cases.

RESULTS

The median age of onset of initial manifestations was 9.5 months, and that of malignant lesions was 7 years. Parents of the patients were not affected, but history of consanguinity was recorded in 38. Initial lesions, such as dryness of the skin and freckles on the face, were noticed in all patients. In addition, erythema of the face with photosensitivity was observed in 21 patients. Premalignant and malignant skin lesions observed later were actinic keratosis in 15 patients, lentigo maligna in one, squamous cell carcinoma (SCC) in 10, and basosquamous carcinoma in one. Eyes were affected with SCC in seven and malignant melanoma (MM) in two patients. SCC of the lip developed in two patients and that of the tongue in one patient. Judicious use of acitretin in 12 patients showed good result.

CONCLUSION

XP in Yemen is characterized by a relatively high incidence, high percentage of consanguinity in parents of the patients, early onset of initial manifestations, malignant tumors, and severe ocular and oral lesions. Acitretin showed good result.

Ocular Features in a Large Cohort of Indians With Xeroderma Pigmentosum

PURPOSE

Xeroderma pigmentosum (XP) is an extreme hypersensitivity to sunlight causing skin freckling and pigmentary changes because of defective DNA repair mechanisms. The purpose of this article is to evaluate the spectrum of ocular and systemic features in XP at a tertiary eye care center in India over 32 years.

METHODS

Data from 418 eyes of 209 patients diagnosed with XP from 1987 to 2018 were reviewed retrospectively for demographics, complaints, ocular features, systemic associations, and their management.

RESULTS

Median age at diagnosis was 2 years (interquartile range, 0.5-5 years). A total of 124 patients (59.3%) were men. There was parental consanguinity in 74.4% cases. Common ocular complaints were photophobia (47.1%), ocular discomfort (45%), defective vision (36.6%), redness (13.4%), tissue growth (12%), white spot (11.2%), and pain (10.5%). At presentation, 43.5% had corneal scars (45.5% were located inferiorly and 70.9% covered visual axis). Corneal vascularization and limbal stem cell deficiency were noted in 37.4%. A total of 56% of patients had at least 1 tumor, and 6.7% had neurological abnormalities. At least 1 ocular surgery was performed in 37.8% of patients. Ophthalmic surgical interventions included tumor excision (23%), keratoplasty (13.4%), and nontumor ocular surface surgery (3.4%).

CONCLUSIONS

XP is a disorder that has high ocular morbidity in Indian patients. The recognition of common signs and symptoms and relative frequency of various ocular complications with time trends will help in managing and reducing the sequelae of this otherwise untreatable and progressive disease.

Genetic diversity and functional effect of common polymorphisms in genes involved in the first heterodimeric complex of the Nucleotide Excision Repair pathway

Nucleotide excision repair is a multistep process that recognizes and eliminates a spectrum of DNA damages. Five proteins, namely XPC, RAD23, Centrin 2, DDB1 and DDB2 act as a heterodimeric complex at the early steps of the NER pathway and play a crucial role in the removal of DNA lesions. Several exonic mutations on genes coding for these proteins have been identified as associated with Xeroderma-pigmentosum (XP), a rare monogenic disorder. However, the role of regulatory polymorphisms in disease development and inter-ethnic diversity is still not well documented. Due to the high incidence rate of XP in Tunisia, we performed a genotyping analysis of 140 SNPs found on these 5 genes in a set of 135-subjects representing the general Tunisian-population. An inter-ethnic comparison based on the genotype frequency of these SNPs have been also conducted. For the most relevant variants, we performed a comprehensive assessment of their functional effects. Linkage disequilibrium and principal component analysis showed that the Tunisian-population is an admixed and intermediate population between Sub-Saharan Africans and Europeans. Using variable factor maps, we identified a list of 20 polymorphisms that contribute considerably to the inter-ethnic diversity of the NER complex. In-silico functional analysis showed that SNPs on XPC, DDB1 and DDB2 are associated with eQTLs mainly DDB2-rs10838681 that seems to decrease significantly the expression level of ACP2 (p = 6.1 × 10^-26). Statistical analysis showed that the allelic frequency of DDB2-rs10838681 in Tunisia is significantly different from all other populations. Using rVarBase, we identified 5 variants on XPC, DDB1 and DDB2 that seem to alter the binding sites of several transcription factors considered as key players in DNA-repair pathways. Results presented in this study provide the first report on regulatory polymorphisms of the NER-complex genes in Tunisia. These results may also help to establish a baseline database for future association and functional studies.

Unusual intraoral cancer with unexpected outcome in a patient with xeroderma pigmentosum: An alert for antineoplastic treatment

Xeroderma pigmentosum (XP) is a rare autosomal disorder characterized by extreme sensitivity to ultraviolet radiation. DNA repair mechanisms are impaired, and minimal sun exposure can lead to the development of cutaneous neoplasms in very young patients. Intraoral carcinomas are uncommon and, when present, are located mainly at the tongue tip. We report an unprecedented case of squamous cell carcinoma (SCC) in the floor of mouth of a 23-year-old woman with XP. The patient was referred to the oncologist, and 2 months after surgical resection, she underwent a single session of chemotherapy plus radiotherapy. However, she died 73 hours after undergoing her first chemotherapy session. Considering the unexpected outcome of this case, we also investigated possible exacerbated adverse effects of antineoplastic treatments (especially cisplatin-based chemotherapy) in patients with XP and reviewed the main characteristics of the disease, especially cases with oral manifestations reported in the literature.

Xeroderma pigmentosum at a tertiary care center in Saudi Arabia

BACKGROUND

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder caused by defective DNA repair that results in extreme sensitivity to ultraviolet (UV) rays. Depending on the type of XP, the disease may affect the skin, eyes and nervous system.

OBJECTIVES

Describe the dermatologic manifestations in patients suffering from XP.

DESIGN

Retrospective, descriptive review of medical records.

SETTING

Dermatology clinic at tertiary care center in Riyadh.

PATIENTS AND METHODS

This study included Saudi patients with clinically confirmed XP.

MAIN OUTCOME MEASURE(S)

Demographic and clinical data including pathology and associated conditions and outcomes.

RESULTS

Of 21 patients with XP, the most common manifestation was lentigines, affecting 18 patients (86%). The most common skin cancer was basal cell carcinoma followed by squamous cell carcinoma (SCC) affecting 15 (71.4%) and 9 (42.8%), respectively. Other skin findings included neurofibroma, trichilemmoma and seborrheic keratosis. Ocular involvement included photophobia, which was the most common finding followed by dryness and ocular malignancies. Two patients showed neurological involvement, which correlated with the type of mutation.

CONCLUSION

Considering that XP is a rare genetic disease, this description of our patient population will aid in early recognition and diagnosis.

LIMITATIONS

Retrospective and small number of patients. Genetic analyses were done for only 5 of the 21 patients.

Diagnosis of Xeroderma Pigmentosum Groups A and C by Detection of Two Prevalent Mutations in West Algerian Population: A Rapid Genotyping Tool for the Frequent XPC Mutation c.1643_1644delTG

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder. Considering that XP patients have a defect of the nucleotide excision repair (NER) pathway which enables them to repair DNA damage caused by UV light, they have an increased risk of developing skin and eyes cancers. In the present study, we investigated the involvement of the prevalent XPA and XPC genes mutations—nonsense mutation (c.682C>T, p.Arg228X) and a two-base-pair (2 bp) deletion (c.1643_1644delTG or p.Val548Ala fsX25), respectively—in 19 index cases from 19 unrelated families in the West of Algeria. For the genetic diagnosis of XPA gene, we proceeded to PCR-RFLP. For the XPC gene, we validated a routine analysis which includes a specific amplification of a short region surrounding the 2 bp deletion using a fluorescent primer and fragment sizing (GeneScan size) on a sequencing gel. Among the 19 index cases, there were 17 homozygous patients for the 2 bp deletion in the XPC gene and 2 homozygous patients carrying the nonsense XPA mutation. Finally, XPC appears to be the major disease-causing gene concerning xeroderma pigmentosum in North Africa. The use of fragment sizing is the simplest method to analyze this 2 bp deletion for the DNA samples coming from countries where the mutation c.1643_1644delTG of XPC gene is prevalent.

Treatment of cancer in a child with ocular xeroderma pigmentosa (XP) in Malawi

A 3-year-old girl presented to the Eye Hospital, Blantyre, Malawi, with multiple ulcerating lesions on her face and in her eyes. Her skin was freckled, with hypopigmented and hyperpigmented areas (poikilodermia) typical of xeroderma pigmentosa. The tumors on the conjunctiva of the right eye and the lower eyelid of the left eye appeared to be squamous cell carcinomas. Chemotherapy with intravenous 5-flourouracil (1000 mg/m) for 5 days and cisplatin (50 mg/m) for 2 days for 3 cycles every 3 weeks was well tolerated. Good response occurred after 1 cycle and after 2 more courses the tumors had resolved.

Living with xeroderma pigmentosum: comprehensive photoprotection for highly photosensitive patients

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease of deoxyribonucleic acid (DNA) repair with ultraviolet (UV) radiation sensitivity and a 10 000-fold increased risk of skin cancer. Symptoms include: freckle-like pigmentation in sun-exposed skin before age 2 years, severe burns after minimal sun exposure (50% of patients) and damage to exposed surfaces of the eyes with loss of vision and ocular cancer. About 25% of patients develop a progressive neurodegeneration. The combination of an inherited inability to repair UV-induced DNA damage and environmental exposure to UV must occur for cutaneous and ocular symptoms to develop. There is no cure for XP, but many of its manifestations may be reduced or prevented through consistent UV protection; thus XP serves as a model for sun protection of patients with marked photosenstivity. Sun protective clothing including hats, sunglasses and face shields, sun screen lotions and avoidance of environmental sources of UV are cornerstones of prevention of skin and eye damage and cancer. Although XP is a serious disease with the potential for limitation of life expectancy, XP patients can live active lives while at the same time avoiding UV.

Xeroderma pigmentosum: man deprived of his right to light

Xeroderma pigmentosum (XP) is a hereditary autosomal recessive disorder characterized by photo hypersensitivity of sun exposed tissues and subsequent several-fold increased risk for malignant changes resulting from impaired ability to repair UV-induced DNA damage. 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 births in Western Europe. Diagnosis is made clinically by the presence of unusual sunburns or lentiginosis or onset of cancers at an early age. It is confirmed by cellular tests for defective DNA repair. Although there is no cure for XP as of now, skin problems can be ameliorated with the use of sunscreens, sun avoidance methods, and recurrent tumor excisions. Oral isotretinoin and topical application of 5-fluorouracil to treat actinic keratoses are other therapeutic options. T4N5 and photolyase liposomal lotions are innovations in the therapy of XP. Genetic counselling implicating the effect of consanguineous marriages should be considered in the management of XP patients.

Unexpected extradermatological findings in 31 patients with xeroderma pigmentosum type C

BACKGROUND

Xeroderma pigmentosum type C (XP-C) is a rare, autosomal, recessive condition characterized by the association of various clinical manifestations mostly involving the skin and eyes.

OBJECTIVES

To evaluate the clinical manifestations in a homogeneous, genetically characterized cohort of patients with XP-C.

METHODS

All patients with XP-C, which was confirmed genetically or by unscheduled DNA synthesis, from the registry of our department and from the French association of patients 'Les Enfants de la Lune' were contacted. During a planned consultation, clinical information was collected using a standardized case-record form.

RESULTS

In total, 31 patients were seen. The mean age at diagnosis was 2.95 years; skin symptoms started at a mean age of 1.49 years. Among the patients, 52% had relatively short stature, with a height-for-weight z-score below -1 SD; 62% showed pyramidal syndrome and 45% had photophobia and/or conjunctivitis. Four patients had several pyogenic granulomas. Twenty-four patients (77%) had skin cancer. The mean age of onset of the first skin cancer was 4.76 years (range 2-14.5 years). Basal-cell carcinoma was the most frequent cancer. Melanomas were rare and mostly desmoplastic. Multinodular thyroid was the most frequent internal tumour.

CONCLUSIONS

Our data highlight several new aspects of XP-C. Patients with XP-C are at risk of developing pyogenic granulomas, desmoplastic melanomas and multinodular thyroid. Involvement of the central nervous system is frequent, but its mechanism remains unclear. The relatively short stature of the patients needs further investigation in order to be explained. XP-C is not only a cancer-prone disorder but is also a polysystemic disorder.

Further evidence of mutational heterogeneity of the XPC gene in Tunisian families: a spectrum of private and ethnic specific mutations

Xeroderma Pigmentosum (XP) is a rare recessive autosomal cancer prone disease, characterized by UV hypersensitivity and early appearance of cutaneous and ocular malignancies. We investigated four unrelated patients suspected to be XP-C. To confirm linkage to XPC gene, genotyping and direct sequencing of XPC gene were performed. Pathogenic effect of novel mutations was confirmed by reverse Transciptase PCR. Mutation screening revealed the presence of two novel mutations g.18246G>A and g.18810G>T in the XPC gene (NG_011763.1). The first is present in one patient XP50NEF, but the second is present in three unrelated patients (XP16KEB, XP28SFA, and XP45GB). These 3 patients are from three different cities of Southern Tunisia and bear the same haplotype, suggesting a founder effect. Reverse Transciptase PCR revealed the absence of the XPC mRNA. In Tunisia, as observed in an other severe genodermatosis, the mutational spectrum of XP-C group seems to be homogeneous with some clusters of heterogeneity that should be taken into account to improve molecular diagnosis of this disease.

c.1643_1644delTG XPC mutation is more frequent in Moroccan patients with xeroderma pigmentosum

Xeroderma pigmentosum is a rare autosomal recessive disease characterized by hypersensitivity to UV light which is due to alterations of the nucleotide excision repair pathway. Eight genes (XPA to XPG and XPV) are responsible for the disease. Among them, the XPC gene is known to be the most mutated in Mediterranean patients. The aim of this study was to determine the frequency of the most common XPC mutation and describe the clinical features of Moroccan patients with xeroderma pigmentosum. Twenty four patients belonging to 21 unrelated Moroccan families and 58 healthy subjects were investigated. After clinical examination, the screening for the c.1643_1644delTG (p.Val548AlafsX25) mutation in the XPC gene was performed by PCR and automated sequencing of exon 9 in all patients and controls. The molecular analysis showed that among the 24 patients, 17 were homozygous for the c.1643_1644delTG mutation and all their tested parents were heterozygous, whereas the others (7 patients) did not carry the mutation. The frequency of this mutation was estimated to be 76.19 % (16/21 families). None of the 58 healthy individuals carried this mutation. In addition, clinical investigation showed that the majority of the patients bearing this mutation have the same clinical features. Our results revealed that the p.Val548AlafsX25 mutation is the major cause (76.19 %) of xeroderma pigmentosum in Moroccan families. This would have an important impact on improving management of patients and their relatives.

[Multiple facial squamous cell carcinomas in a child, revealing a xeroderma pigmentosum]

BACKGROUND

Squamous cell carcinoma of the skin is very rare in children. One of its most common risk factors is xeroderma pigmentosum (XP), an autosomal recessive disease characterized by defective cellular DNA repair, and hypersensitivity to ultraviolet radiation.

CASE REPORT

We report a case of XP in a 7-year-old black African boy, revealed by squamous cell carcinomas of the inferior lip and upper left eyelid.

DISCUSSION

In sub-Saharan regions, the early diagnosis of XP is difficult because of its uncommon occurrence on black skin and black skin specificities. The strong sun radiation in the tropics and a late diagnosis make XP treatment challenging. Thus, prevention in patients' families is mandatory.

Ophthalmic manifestations and histopathology of xeroderma pigmentosum: two clinicopathological cases and a review of the literature

Xeroderma pigmentosum is a rare, autosomal recessive disease caused by a defect in DNA repair. Patients with xeroderma pigmentosum often have cutaneous and ocular sun sensitivity, freckle-like skin pigmentation, multiple skin and eye cancers, and, in some patients, progressive neurodegeneration. Xeroderma pigmentosum predominantly affects the ultraviolet (UV) exposed ocular surface, resulting in eyelid atrophy and cancers, corneal dryness, exposure keratopathy, and conjunctival tumors. We report the clinical history and ocular pathology of two white women who had xeroderma pigmentosum with neurological degeneration: Case 1 (died at age 44 years) and Case 2 (died at age 45 years). Case 1, with mutations in the XPA gene, had more than 180 basal cell carcinomas of her skin and eyelids and died from complications of neurodegeneration. Case 2, with mutations in the XPD gene, was sun-protected and had three skin cancers. She died from complications of neurodegeneration and pneumonia. Both patients had bilateral pinguecula, corneal pannus, and exposure keratopathy. Case 1 had bilateral optic atrophy, and Case 2 had bilateral peripheral retinal pigmentary degeneration. Both patients developed retinal gliosis. The ophthalmic manifestations and pathology of xeroderma pigmentosum are discussed and reviewed with respect to this report and other cases in the literature. These cases illustrate the role of DNA repair in protection of the eyes from UV damage and neurodegeneration of the retina.

Cancer and neurologic degeneration in xeroderma pigmentosum: long term follow-up characterises the role of DNA repair

BACKGROUND

The frequency of cancer, neurologic degeneration and mortality in xeroderma pigmentosum (XP) patients with defective DNA repair was determined in a four decade natural history study.

METHODS

All 106 XP patients admitted to the National Institutes of Health from 1971 to 2009 were evaluated from clinical records and follow-up.

RESULTS

In the 65 per cent (n=69) of patients with skin cancer, non-melanoma skin cancer (NMSC) was increased 10,000-fold and melanoma was increased 2000-fold in patients under age 20. The 9 year median age at diagnosis of first non-melanoma skin cancer (NMSC) (n=64) was significantly younger than the 22 year median age at diagnosis of first melanoma (n=38)-a relative age reversal from the general population suggesting different mechanisms of carcinogenesis between NMSC and melanoma. XP patients with pronounced burning on minimal sun exposure (n=65) were less likely to develop skin cancer than those who did not. This may be related to the extreme sun protection they receive from an earlier age, decreasing their total ultraviolet exposure. Progressive neurologic degeneration was present in 24% (n=25) with 16/25 in complementation group XP-D. The most common causes of death were skin cancer (34%, n=10), neurologic degeneration (31%, n=9), and internal cancer (17%, n=5). The median age at death (29 years) in XP patients with neurodegeneration was significantly younger than those XP patients without neurodegeneration (37 years) (p=0.02).

CONCLUSION

This 39 year follow-up study of XP patients indicates a major role of DNA repair genes in the aetiology of skin cancer and neurologic degeneration.

Xeroderma pigmentosum: a retrospective case series in Zimbabwe

PURPOSE

To present our experience with the clinical features and management of black African patients with xeroderma pigmentosum (XP).

PATIENTS AND METHODS

Twelve patients with XP were seen over a 25-year period, and were retrospectively reviewed for age, gender, clinical features, treatment, and follow-up.

RESULTS

There were 8 females and 4 males with an age range of 3 to 18 years. One patient, the longest survivor, was followed until death at 18 years. Nine patients had the severe form of XP and 3 had the mild form. All patients had early ocular involvement with photophobia and early blindness. Squamous cell carcinoma (SCC) was present on the skin, lip, and tongue in most patients. One patient had ocular surface SCC. There was marked skin photosensitivity. No history of consanguinity was noted in the parents of the patients. Surgery was the treatment modality of choice. Follow-up was poor.

CONCLUSION

XP is uncommon in our black population, and presents in the severe form with SCC as the malignant skin, lip, and tongue lesion. It is common in early childhood with severe photosensitivity, photophobia, and eventual blindness. Follow-up is difficult in our environment.

Incidence of DNA repair deficiency disorders in western Europe: Xeroderma pigmentosum, Cockayne syndrome and trichothiodystrophy

Laboratory diagnosis for DNA repair diseases has been performed in western Europe from the early seventies for xeroderma pigmentosum (XP) and from the mid-eighties for Cockayne syndrome (CS) and trichothiodystrophy (TTD). The combined data from the DNA repair diagnostic centres in France, (West) Germany, Italy, the Netherlands and the United Kingdom have been investigated for three groups of diseases: XP (including XP-variant), CS (including XP/CS complex) and TTD. Incidences in western Europe were for the first time established at 2.3 per million livebirths for XP, 2.7 per million for CS and 1.2 per million for TTD. As immigrant populations were disproportionately represented in the patients' groups, incidences were also established for the autochthonic western European population at: 0.9 per million for XP, 1.8 per million for CS and 1.1 per million for TTD. Perhaps contrary to general conceptions, compared to XP the incidence of CS appears to be somewhat higher and the incidence of TTD to be quite similar in the native West-European population.

Atypical fibroxanthoma and squamous cell carcinoma of the conjunctiva in xeroderma pigmentosum

Patients with xeroderma pigmentosum (XP) have defective DNA repair and a high predisposition to developing abnormalities and neoplasia in the sun-exposed areas of the skin and mucous membranes. The most common tumors reported in patients with XP are squamous cell carcinomas, basal cell carcinomas, and melanomas. Atypical fibroxanthoma (AFX) is a pleomorphic tumor that arises predominantly in the sun-damaged skin of the head and neck regions of the elderly. We describe a unique case of a 6-year-old African American boy with XP who developed an atypical fibroxanthoma and 2 squamous cell carcinomas in the conjunctiva. The clinical and histopathologic findings of AFX are discussed.

Tumeurs cutanées au cours du xeroderma pigmentosum au Maroc

INTRODUCTION

Xeroderma pigmentosum is a rare recessive and autosomically transmitted genodermatosis. Its cutaneous manifestations are dominated by skin cancers. This investigation aims at studying the epidemiologic, clinic, histologic, therapeutic and evolutive aspects of the skin tumors during xeroderma pigmentosum.

PATIENTS AND METHODS

A retrospective monocentric study was carried out in the Dermatology and Veneorology Department of Ibn Rochd University Hospital of Casablanca, Morocco. It included all the xeroderma pigmentosum admitted to hospital or followed-up from 1990 to 2000. All the dossiers were included. The anatomopathologic study was carried out in all the skin tumor cases.

RESULTS

One hundred and twenty xeroderma pigmentosum were admitted in 10 Years. Fifty-four percent of the cases were females and 46 p. 100 were males. The mean apparition of the first tumor was 7.7 Years. One hundred and fifty-three skin tumors were diagnosed in 96 patients (80 p. 100). These tumors were of basocellular carcinoma type in 32.6 p. 100, of squamous cell carcinoma type in 33.9 p. 100 and of melanoma type in 11 p. 100. Ocular tumors were found in 31 cases (25.8 p. 100) and buccal in 8 cases. Therapeutically, the surgical exeresis of one or many tumors was performed in all cases. Electrocoagulation was associated in 42 p. 100 of the cases and skin graft in 52 p. 100. Cutaneous relapses after surgery were noticed in 55 cases (57.2 p. 100). Twenty-five patients died and 31 were lost to follow-up.

DISCUSSION

Our series is characterized by a large frequency of mainly cutaneous tumors (80 p. 100) in comparison with the largest review of literature (45 p. 100). These tumors were mainly represented by basocellular and squamous cell carcinoma with onset at an early age (7.7 Years). Our series is also characterized by a large frequency of cutaneous relapses after surgery (51.6 p. 100). Neglecting advice on photoprotection and the lack of regular control visits lead to the proliferation of large size tumors, making therapeutic strategies difficult or even impossible.