DNA repair-related heritable photosensitivity syndromes: Mutation landscape in a multiethnic cohort of 17 multigenerational families with high degree of consanguinity

Inherited photosensitivity syndromes are a heterogeneous group of genetic skin disorders with tremendous phenotypic variability, characterized by photosensitivity and defective DNA repair, especially nucleotide excision repair. A cohort of 17 Iranian families with heritable photosensitivity syndromes was evaluated to identify their genetic defect. The patients' DNA was analyzed with either whole-exome sequencing or RNA sequencing (RNA-Seq). The interpretations of the genomic results were guided by genome-wide homozygosity mapping. Haplotype analysis was performed for cases with recurrent mutations. RNA-Seq, in addition to mutation detection, was also utilized to confirm the pathogenicity. Thirteen sequence variants, including six previously unreported pathogenic variants, were disclosed in 17 Iranian families, with XPC as the most common mutated gene in 10 families (59%). In one patient, RNA-Seq, as a first-tier diagnostic approach, revealed a non-canonical homozygous germline variant: XPC:c.413-9 T > A. The Sashimi plot showed skipping of exon 4 with dramatic XPC down-expression. Haplotype analysis of XPC:c.2251-1 G>C and XPC:1243 C>T in four families showed common haplotypes of 1.7 Mb and 2.6 Mb, respectively, denoting a founder effect. Lastly, two extremely rare cases were presented in this report: a homozygous UVSSA:c .1990 C>T was disclosed, and ERCC2-related cerebro-oculo-facio-skeletal (COFS) syndrome with an early childhood death. A direct comparison of our data with the results of previously reported cohorts demonstrates the international mutation landscape of DNA repair-related photosensitivity disorders, although population-specific differences were observed.

Translating patient needs into medical device development: co-design of a photoprotection visor for Xeroderma Pigmentosum using qualitative interviews

INTRODUCTION

People with Xeroderma Pigmentosum (XP) have a heightened sensitivity to ultraviolet radiation (UVR) and are advised to wear photoprotective clothing including a visor covering the face and neck. Photoprotective visors are homemade and predominately worn by children with decreasing frequency as age increases. To improve upon the current design and efficacy we were tasked with developing a prototype visor to meet patients' needs.

METHODS

Adopting a codesign methodology, patients' experiences of wearing a visor and patient and carer views of emerging prototypes were explored during interviews. A thematic analysis was conducted in parallel with data collection and themes were interpreted into design cues; desirable attributes of a visor that would counteract the negative user experiences and meet the requirements described by patients and carers. The design cues guided the iterative development of prototypes by academic engineers.

RESULTS

Twenty-four interviews were conducted with patients and carers. Thematic analysis resulted in the following five themes: Being safe from UVR exposure; self-consciousness; temperature effects; acoustic difficulties; and material properties. The following design cues were developed from the themes respectively; materials and design with high UVR protection; ability to customise with own headwear; ventilation to reduce steaming up; acoustic functionality to enable hearing and speech; foldable, portable, and easy to put on and take off.

CONCLUSIONS

It is important to understand people's experiences of using medical devices to improve their safety, efficiency and user satisfaction. The user experience themes and design cues, informed the iterative development of low fidelity visor prototypes as part of a codesign process. These design cues and responses to the prototypes are guiding commercial manufacturing and regulatory approval. The visor can then be prescribed to patients, providing an equitable service of care.

Brazilian XP-E siblings carrying a novel DDB2 variant developed early-onset melanoma: a case report

BACKGROUND

Xeroderma pigmentosum group E (XP-E) is one of the least common forms of XP, a rare syndrome where patients are prone to develop skin cancer in exposed sunlight areas. XP-E patients are generally not diagnosed until they are adults due to the mild phenotype.

CASE PRESENTATION

two XP-E siblings, female, 23 years, and male, 25 years, from a Brazilian consanguineous family carrying the novel missense pathogenic variant in DDB2 gene, NM_000107.3:c.1027G > C, associated with skin cancer early-onset and severe phenotype, as nodular melanoma in the cornea and in the ear.

CONCLUSION

The assessment of genomic variant pathogenicity was a challenge since this family belongs to an underrepresented population in genomic databases. Given the scarcity of literature documenting XP-E cases and the challenges encountered in achieving an early diagnosis, this report emphasizes the imperative of sun protection measures in XP-E patients. Additionally, it highlights the detrimental impact of the COVID-19 pandemic on cancer diagnosis, leading to the manifestation of a severe phenotype in affected individuals.

Why? What? How? Using an Intervention Mapping approach to develop a personalised intervention to improve adherence to photoprotection in patients with Xeroderma Pigmentosum

Background: Intervention Mapping (IM) is a systematic approach for developing theory-based interventions across a variety of contexts and settings. This paper describes the development of a complex intervention designed to reduce the dose of ultraviolet radiation (UVR) reaching the face of adults with Xeroderma Pigmentosum (XP), by improving photoprotection. XP is a genetic condition that without extreme UVR photoprotection, leads to high risk of developing skin cancer.

Methods: The IM protocol of 6 steps was applied, involving comprehensive mixed-methods formative research. Key stakeholders (XP clinical staff and Patient and Public Involvement Panel), were instrumental at every step. Behaviour change methods were informed by the IM taxonomy, therapeutic approaches (e.g. ACT, CBT) and coded according to the taxonomy of behaviour change techniques (version 1).

Results: We designed a personalised modular intervention to target psychosocial determinants of photoprotective activities that influence the amount of UVR reaching the face. Content was developed to target determinants of motivation to protect and factors preventing the enactment of behaviours. Participants received personalised content addressing determinants/barriers most relevant to them, as well as core ‘behaviour-change’ material, considered important for all (e.g. SMART goals). Core and personalised content was delivered via 7 one-to-one sessions with a trained facilitator using a manual and purpose designed materials: Magazine; text messages; sunscreen application video; goal-setting tools (e.g. UVR dial and face protection guide); activity sheets. Novel features included use of ACT-based values to enhance intrinsic motivation, targeting of emotional barriers to photoprotection, addressing appearance concerns and facilitating habit formation.

Conclusion: IM was an effective approach for complex intervention design. The structure (e.g. use of matrices) tethered the intervention tightly to theory and evidence-based approaches. The significant amount of time required needs to be considered and may hinder translation of IM into clinical and non-academic settings.

Psychological correlates of adherence to photoprotection in a rare disease: International survey of people with Xeroderma Pigmentosum

OBJECTIVES

Xeroderma pigmentosum (XP) is an extremely rare genetic disorder (approximately 100 known cases in the United Kingdom), where DNA damage caused by ultraviolet radiation in daylight cannot be repaired. Adherence to photoprotection is essential to prevent skin cancer. We investigated psychological correlates of photoprotection in the XP population of Western Europe and the United States.

DESIGN

Cross-sectional survey of adults with XP and caregivers of patients <16 years and those with cognitive impairment in the United Kingdom, Germany, the United States, and France (n = 156).

METHODS

Photoprotection activities to protect the face and body when outdoors; avoidance of going outside during daylight hours; intention; self-efficacy; and social support were assessed using measures developed for this study. Participants answered questions about their illness representations of XP (BIPQ); beliefs about photoprotection (BMQ); automaticity (i.e., without conscious effort) (SRBAI); clinical and demographic characteristics. Ordinal logistic regressions determined factors associated with photoprotection.

RESULTS

One third did not achieve optimal face photoprotection. After controlling for demographic and clinical factors, modifiable correlates of higher photoprotection included greater perceived control of XP, stronger beliefs in necessity and effectiveness of photoprotection, and higher intention. Avoidance of going outside was associated with greater photoprotection concerns, more serious illness consequences, and higher XP-related distress. Greater automaticity and higher self-efficacy were associated with better protection across all outcomes.

CONCLUSIONS

Approximately half of all known cases across three European countries participated. Identified modifiable predictors of photoprotection may be targeted by interventions to reduce the incidence of skin cancers in the immediate future, when a treatment breakthrough is unlikely. Statement of contribution What is already known on this subject? Adherence to photoprotection in other populations at elevated risk from skin cancer is poor; however, the level in XP is unknown. Research across chronic conditions shows that adherence to treatment and lifestyle recommendations are influenced by illness perceptions, self-efficacy, and treatment beliefs. Studies on photoprotection conducted with the general population have found that perceived risk, perceptions of ultraviolet radiation (UVR) protection, self-efficacy for the behaviour, and automaticity (behaviours that are enacted with little conscious awareness) are related to better photoprotection. What does this study add? This is the first international survey to examine adherence and its correlates in people with XP (an under-researched group at very high risk of fatal skin cancer). Adherence varies and at least one third have potential for improvement. Perceptions about XP, photoprotection beliefs, self-efficacy, intention, and automaticity were associated with photoprotection of the face and body when outdoors. Negative emotional representations of XP were associated with avoidance of going outside during daylight hours.

Macular and Retinal Nerve Fibre Layer Thinning in Xeroderma Pigmentosum: A Cross-sectional Study

The purpose of this study was to evaluate retinal thickness in different Xeroderma Pigmentosum (XP) complementation groups using spectral-domain optical coherence tomography (SD-OCT). This was a cross-sectional pilot study of 40 patients with XP. All patients had healthy-looking retinae and optic nerves on slit lamp biomicroscopy, and subtle or no neurological deficits. Patients were divided into two groups based on the known tendency for neurodegeneration associated with certain XP complementation groups. A third control group was obtained from a normative database. Using SD-OCT, we compared peripapillary retinal nerve fibre layer (pRNFL) and macular thickness between the groups. XP patients with a known tendency for neurodegeneration were found to have a statistically significant reduction in both pRNFL (p < 0.01) and macular thickness (p < 0.001) compared with healthy controls. In contrast, there was no statistically significant difference between pRNFL and macular thickness in XP patients not expected to develop neurodegeneration compared to the same control group. When both XP groups were compared, a statistically significant reduction in total pRNFL (p = 0.02) and macular thickness (p = 0.002) was found in XP patients predisposed to neurodegeneration. Our results suggest that pRNFL and macular thickness are reduced in XP patients with a known tendency for neurodegeneration, even before any marked neurological deficits become manifest. These findings demonstrate the potential role of retinal thickness as an anatomic biomarker and prognostic indicator for XP neurodegeneration.

Coupling between nucleotide excision repair and gene expression

Gene expression and DNA repair are fundamental processes for life. During the last decade, accumulating experimental evidence point towards different modes of coupling between these processes. Here we discuss the molecular mechanisms by which RNAPII-dependent transcription affects repair by the Nucleotide Excision Repair system (NER) and how NER activity, through the generation of single stranded DNA intermediates and activation of the DNA damage response kinase ATR, drives gene expression in a genotoxic scenario. Since NER-dependent repair is compromised in Xeroderma Pigmentosum (XP) patients, and having in mind that these patients present a high degree of clinical heterogeneity, we speculate that some of the clinical features of XP patients can be explained by misregulation of gene expression.

Inhalation anesthesia in a patient with xeroderma pigmentosum: a case report

INTRODUCTION

Xeroderma Pigmentosum (XP) is a rare autosomal recessive disease, which is defined by extreme sensitivity to sunlight and UV radiation and characterized by skin lesions and neuromuscular abnormalities. It is caused by a molecular defect in nucleotide excision repair genes. It has been reported that volatile anesthetics may cause genotoxic side effects or aggravation of the neurological signs. We report an XP patient with difficult intubation whose airway was controlled with Laryngeal Mask Airway (LMA) and was anesthetized with sevoflurane.

CASE PRESENTATION

A 23-year-old woman, who had been a known case of XP since her childhood, was admitted to our hospital for excision of face mass (SCC) and skin graft surgery. Her airway examination revealed some anatomical and pathological abnormalities, including limitation of mouth opening, jaw protrusion, head extension, and class 4 of mallampati, all predicting difficult intubation. We chose general anesthesia with inhalation induction, LMA insertion and maintenance with sevoflurane without muscle relaxant. The surgery was completed uneventfully and the patient left the hospital the day after the surgery without any new complaint.

CONCLUSIONS

We suggest that for XP patients with compromised air-way, sevoflurane (not all volatiles) may be preferred.

Identification of a novel nonsense mutation in POLH in a Chinese pedigree with xeroderma pigmentosum, variant type

Xeroderma pigmentosum-variant (XPV) is one type of XP, a rare autosomal recessive disorder, and caused by defects in the post replication repair machinery while nucleotide-excision repair (NER) is not impaired. In the present study, we reported a Chinese family with XPV phenotype, which was confirmed by histopathological results. Genetic variants were detected by polymerase chain reaction and exon sequencing. Furthermore, the reported molecular defects in XPV patients from previous literatures were reviewed. A homozygous c.67C>T mutation in the exon 2 of DNA polymerase eta (POLH), a novel non-sense mutation in POLH, was discovered.