Why epidermodysplasia verruciformis - a rare genetic disease - has raised such great interest

Systemic Retinoids for Generalized Verrucosis Due to Congenital Immunodeficiency: Case Reports and Review of the Literature

Generalized verrucosis (GV) is a group of immunodeficiency disorders accompanied by widespread human papillomavirus infection. We revisit two cases of GV due to congenital interleukin-7 deficiency successfully treated with systemic retinoids. We also present a review of the literature on the use of systemic retinoids to treat GV. Our review suggests that systemic retinoids are a safe and effective option for managing recalcitrant wart lesions in cases of GV.

Whole transcriptome-based skin virome profiling in typical epidermodysplasia verruciformis reveals α-, β-, and γ-HPV infections

HPVs are DNA viruses include approximately 450 types that are classified into 5 genera (α-, β-, γ-, μ-, and ν-HPV). The γ- and β-HPVs are present in low copy numbers in healthy individuals; however, in patients with an inborn error of immunity, certain species of β-HPVs can cause epidermodysplasia verruciformis (EV), manifesting as recalcitrant cutaneous warts and skin cancer. EV presents as either typical or atypical. Manifestations of typical EV are limited to the skin and are caused by abnormal keratinocyte-intrinsic immunity to β-HPVs due to pathogenic sequence variants in TMC6, TMC8, or CIB1. We applied a transcriptome-based computational pipeline, VirPy, to RNA extracted from normal-appearing skin and wart samples of patients with typical EV to explore the viral and human genetic determinants. In 26 patients, 9 distinct biallelic mutations were detected in TMC6, TMC8, and CIB1, 7 of which are previously unreported to our knowledge. Additionally, 20 different HPV species, including 3 α-HPVs, 16 β-HPVs, and 1 γ-HPV, were detected, 8 of which are reported here for the first time to our knowledge in patients with EV (β-HPV-37, -47, -80, -151, and -159; α-HPV-2 and -57; and γ-HPV-128). This study expands the TMC6, TMC8, and CIB1 sequence variant spectrum and implicates new HPV subtypes in the pathogenesis of typical EV.

Re-evaluation of epidermodysplasia verruciformis: Reconciling more than 90 years of debate

Epidermodysplasia verruciformis (EV) is a rare genodermatosis characterized by abnormal susceptibility to cutaneous human beta-papillomavirus infections causing persistent flat warts or pityriasis versicolor-like lesions. This generalized verrucous skin disorder resembles generalized verrucosis, but these 2 conditions are distinguished by differences in clinical manifestation and the human papillomavirus types involved. A breakthrough in our understanding of EV was the discovery that homozygous inactivating mutations in TMC6 (EVER1) and TMC8 (EVER2) determine susceptibility to this disorder; however, they have not solved all EV cases fully. These deficiencies account for 75% of affected individuals, leaving a substantial number of patients without an underlying genetic cause. Recently, it has been revealed that mutations in additional genes (RHOH, MST-1, CORO1A, and IL-7) result in extensive human beta-papillomavirus replication and therefore manifest with an EV-like phenotype. The term "acquired EV" is used to describe an EV-like phenotype that develops in immunocompromised hosts, and the introduction of this entity further aggravates the confusion. Reevaluation of these entities is warranted. Here, we review the available data on this issue, provide up to date information on the major characteristics that differentiate between these seemingly clinically similar disorders, and highlight the different mechanisms involved in each disorder.

Clinical aspects of epidermodysplasia verruciformis and review of the literature

BACKGROUND

Epidermodysplasia verruciformis (EV), is an unusual genodermatosis characterized by persistent human papilloma virus infection with an autosomal recessive inheritance pattern. Clinically, it is characterized by flat wart-like lesions, scaly hypo- and hyperpigmented macules and/or patches, which resemble pityriasis versicolor, and development of early beginning nonmelanoma cutaneous carcinomas.

METHODS

The epidemiological and clinical features of seven cases with EV that have been followed up for 5 years were included in the study.

RESULTS

Seven cases consisted of four males and three females. All seven cases were working outdoors. Three cases were the product of consanguineous marriages. The onset of the lesions was between the ages of 1-20 years (the average age was 9.29 years). The initial appearance of cutaneous tumors were between the ages 15-34 years (average age: 21.28 years). Six of seven cases had malignant cutaneous tumors, of which histopathological examination revealed squamous cell carcinoma (SCC). Three of our cases had radiotherapy previously for the existing SCCs. These cases had more early malignant transformations.

CONCLUSION

Radiotherapy applied against the SCC previously, together with sunlight exposure may cause early malignant transformation of skin lesions and the destructive tumors.

Allogeneic transplantation and the risk for transmission of genetic disease: the heritable cancer disorders

With the development of new approaches to transplantation therapy, such as those building upon the potential found in stem cells, it is vital to pursue a clear understanding of transplantation risks. Allogeneic transplantation presents risk for the transmission of disease of various types, including genetic disease. Predisposition to develop cancer is a feature of numerous genetic disorders, and it may be transmissible by transplantation. Some genetic disorders predisposing to cancer are remarkably common, either worldwide or in specific populations, and they could pose significant risk. Hence, to reduce risk to recipients, there is reason to exclude from donation those potential donors (including embryos) harboring certain germ-line mutations. However, the frequent absence of readily identifiable features might confound the effort to exclude those who harbor mutation. Thus, it is also important to consider the magnitude of risk that they represent. For some disorders, life-threatening cancer is highly likely to develop in those individuals born with germ-line mutation, but whether recipients would face the same risk from transplanted mutation is not always evident. Given the diversity of pathways that lead to cancer, there may be diverse factors that impact the likelihood for cancer to develop in the recipient, with some factors decreasing and others increasing the risk. One factor of special concern is the possibility that manipulation of donor cells, prior to transplantation, might introduce additional genetic or epigenetic abnormality, thereby increasing the risk.

An unusual presentation of human papillomavirus (HPV) infection in a black epidermodysplasia verruciformis (EV) patient

A 25-year-old black man had a 20-year history of disseminated plaques on his body. Two years before consultation he noticed several tumors on the genitalia. Physical examination revealed generalized, coalescing, hypopigmented plaques with a very defined and keratotic border that resembled actinic porokeratosis. (Fig. 1). Multiple verrucous and moist tumors were observed on the scrotum (Fig. 2). His past medical history was unremarkable, and no family member had the disease. Histology of the body lesions revealed hyperkeratosis with a horny-layer, basket-weave appearance, large and clear blue-gray keratinocytes with finely granular cytoplasm and vacuolized nuclei, and abundant keratohyaline granules located in the upper epidermal layer (Fig. 3). Scrotum biopsy showed hyperkeratosis, irregular acanthosis with papillomatosis, and koilocytic figures. The genital lesions were treated with monthly cryotherapy plus surgical excision with complete disappearance of the lesions. A decrease in ultraviolet exposure and daily sun-block were encouraged for epidermodysplasia verruciformis lesions. After genital wart clearance, follow-ups are being scheduled every 4 months, with no new lesions to date.

The Effect of Ultraviolet Radiation on Human Viral Infections

Exposure to UV radiation is recognized to suppress cell-mediated immunity and therefore could adversely affect the course of a viral infection. Rodent models of viral infection confirm this possibility but the situation in human subjects is not so clear, apart from two exceptions. These are herpes simplex, in which sunlight exposure can cause reactivation, and certain papillomavirus types in which sunlight exposure can lead to the development of nonmelanoma skin cancer. In both cases, there are UV response elements in the viral genomes that alter the normal interactions between the viruses and the host following exposure, and UV-induced effects on the immune response occur in addition. These complex mechanisms are discussed, and the situation regarding UV radiation and viral exanthems plus other viruses, including the retroviruses, summarized. Finally viral vaccination is considered in the context of UV exposure and the importance of the host's genetic background emphasized. Further research is required to evaluate whether sunlight can significantly affect the resistance to common viral infections and vaccines.