Dystrophic epidermolysis bullosa pruriginosa of elderly onset

Genetic diagnosis of a rare COL7A1 variant causing dystrophic epidermolysis bullosa pruriginosa through whole‑exome sequencing

Dystrophic epidermolysis bullosa pruriginosa (DEB-Pr) is a rare subtype of inherited DEB. In the present study, whole-exome sequencing was conducted on 12 individuals from the same affected family and a rare heterozygous variation was identified in the collagen type VII, α1 (COL7A1) gene, namely c.6859G>A (p.Gly2287Arg). Subsequently, this heterozygous variant was confirmed using Sanger sequencing of individual plasma cell-free DNA (cfDNA) and it was demonstrated for the first time, to the best of our knowledge, that COL7A1 exons can be amplified from plasma cfDNA. Within the large pedigree examined, 14 out of 18 individuals carried the variant, 3 carried the wild type, and one exceptional case, III-9, showed no disease symptoms despite carrying the disease variant. A general association between genotype and phenotype was established. Of note, the mutation landscape indicated that this G2287R variant is primarily reported in Asian countries. In silico structure prediction suggested that the residue resulting from the mutation may affect collagen protein stability. In conclusion, the present study provides evidence for the involvement of the COL7A1 G2287R gene variant in the development of DEB-Pr and highlights the potential utility of cfDNA in genetic disease diagnosis.

Promising effect of intravenous immunoglobulin therapy for epidermolysis bullosa pruriginosa

BACKGROUND

Epidermolysis bullosa pruriginosa (EBP) is rare a clinical variant of dystrophic epidermolysis bullosa characterized by trauma-induced bullae formation, milia and nail dystrophy accompanied by severe pruritus. Treatment pruritus of EBP focuses on immunosuppressive treatment with limited efficacy. Treatment strategies are not well-established.

AIM

To provide the genetic characterization of a multi-generational EBP family and discuss the efficacy of intravenous immunoglobulin treatment in EBP.

MATERIALS & METHODS

The clinical characteristics of patients diagnosed with EBP in three consecutive generations were determined. The mutation is analyzed in the index patient's genomic DNA by Sanger sequencing, and this mutation was confirmed in other affected members of the family. Index case with severe phenotype was treated with intravenous immunoglobulin (IVIG).

RESULTS

A heterozygous single nucleotide transition, c.6127G>A, in exon 73 of COL7A1 was identified in all affected members. Physical examination of patients revealed lichenoid papules on extensor surfaces of extremities, excoriations, milia formation and nail dystrophy. Majority of patients had elevated serum IgE levels (%86 (6/7)) without a medical history for atopy. Female patients had generalized involvement and severe phenotype. The skin lesions of the index case were refractory to high dose systemic steroids and cyclosporine treatment. Lesions improved significantly with intravenous immunoglobulin therapy.

CONCLUSION

In severe cases, unresponsive to other therapies, IVIG may be a preferable therapeutic approach to modulate the inflammatory response in patients with EBP.

Consensus reclassification of inherited epidermolysis bullosa and other disorders with skin fragility

BACKGROUND

Several new genes and clinical subtypes have been identified since the publication in 2014 of the report of the last International Consensus Meeting on Epidermolysis Bullosa (EB).

OBJECTIVES

We sought to reclassify disorders with skin fragility, with a focus on EB, based on new clinical and molecular data.

METHODS

This was a consensus expert review.

RESULTS

In this latest consensus report, we introduce the concept of genetic disorders with skin fragility, of which classical EB represents the prototype. Other disorders with skin fragility, where blisters are a minor part of the clinical picture or are not seen because skin cleavage is very superficial, are classified as separate categories. These include peeling skin disorders, erosive disorders, hyperkeratotic disorders, and connective tissue disorders with skin fragility. Because of the common manifestation of skin fragility, these 'EB-related' disorders should be considered under the EB umbrella in terms of medical and socioeconomic provision of care.

CONCLUSIONS

The proposed classification scheme should be of value both to clinicians and researchers, emphasizing both clinical and genetic features of EB. What is already known about this topic? Epidermolysis bullosa (EB) is a group of genetic disorders with skin blistering. The last updated recommendations on diagnosis and classification were published in 2014. What does this study add? We introduce the concept of genetic disorders with skin fragility, of which classical EB represents the prototype. Clinical and genetic aspects, genotype-phenotype correlations, disease-modifying factors and natural history of EB are reviewed. Other disorders with skin fragility, e.g. peeling skin disorders, erosive disorders, hyperkeratotic disorders, and connective tissue disorders with skin fragility are classified as separate categories; these 'EB-related' disorders should be considered under the EB umbrella in terms of medical and socioeconomic provision of care. Linked Comment: Pope. Br J Dermatol 2020; 183:603.

Epidermolysis bullosa pruriginosa: A rare entity which responded well to thalidomide

Epidermolysis bullosa pruriginosa is an unusual clinical variant of dystrophic epidermolysis bullosa characterized by sublamina densa blistering and intense pruritus leading to hypertrophic lichenoid nodules, plaques, milia, and variable presence of albopapuloid lesions. Most cases are sporadic but a few cases have autosomal dominant or recessive inheritance. Treatment has been quite disappointing and failed to produce satisfactory or sustained results. We report a case of 39-years-old male with epidermolysis bullosa pruriginosa and its response to thalidomide.

Coinheritance of 2 New Potentially Damaging Heterozygous COL7A1 Variants in a Family With Autosomal Dominant Epidermolysis Bullosa Pruriginosa

Epidermolysis bullosa pruriginosa (EBP) is a rare subtype of EB which is characterized by intense pruritus with blistering and nodular or lichenoid lesions most prominent on the lower extremities. It is caused by variants in COL7A1 which encodes for type VII collagen. There is wide phenotypic and genotypic variability between affected individuals. We report 2 potentially pathogenic variants in COL7A1 occurring on the same allele in a family with EBP and autosomal dominant inheritance. Late-onset EBP and incomplete penetrance may lead to delayed presentation in affected family members with the same variants. The broad phenotypic variability seen in EBP suggests that further genotypic and environmental factors may influence presentation. Genetic and histopathological diagnosis is essential, given the considerable overlap with clinically similar presentations such as hypertrophic lichen planus.

Multiple Milia as an Isolated Skin Manifestation of Dominant Dystrophic Epidermolysis Bullosa: Evidence of Phenotypic Variability

We report a Japanese pedigree with dominant dystrophic epidermolysis bullosa (DDEB) harboring the p.G2251E mutation of COL7A1. The proband of this pedigree presented with multiple milia as an isolated skin manifestation without a history of blistering and subsequently developed generalized intractable blisters, suggesting that multiple milia could be a primary manifestation of DDEB. Her mother exhibited nail dystrophy and pruritic nodules and her elder sister was unaffected, despite having the same COL7A1 mutation. Inter- and intrafamilial clinical variability are often observed in DDEB, so we should be aware of this factor to provide appropriate genetic counselling.

Epidermolysis bullosa pruriginosa: a systematic review exploring genotype-phenotype correlation

INTRODUCTION

Epidermolysis bullosa pruriginosa (EBP) is a clinical variant of dystrophic epidermolysis bullosa (DEB), characterized by intense pruritus and hypertrophic, lichenified, prurigo-like papules, plaques, and nodules secondary to scratching. These clinical findings have been attributed to various mutations in the COL7A1 gene. Previous reports have yielded inconsistent findings regarding a possible genotype-phenotype relationship in EBP.

OBJECTIVE

Our aim was to conduct a systematic review aimed at assessing the genotype-phenotype correlation in EBP.

METHODS

A systematic review was conducted using PubMed, Medline, EMBASE, and Cochrane databases for all reports of mutation-verified EBP, published from 1946 to September 2014. Statistical comparison of clinical findings between mutation types was performed using logistic regression analysis.

RESULTS

The review included a total of 28 articles with 74 individuals, which consisted of level 4 non-controlled case series (grade C) and level 5 case reports (grade D). Previous reported mutation types included glycine substitution (GS, 52.7%), in-frame skipping (IFS, 33.8%), non-glycine substitution (NGS, 8.1%), and premature termination codon (PTC, 5.4%). The most common clinical findings were extremities involvement, linear configuration, and nail dystrophy. In comparison with GS mutation carriers, IFS carriers had a higher likelihood of (1) being male (OR 2.99; p = 0.043; 95% CI 1.27-11.4) and (2) presenting with blisters (OR 4.10; p = 0.013; 95% CI 1.34-12.5).

CONCLUSIONS

To our knowledge, this study is the first systematic review examining the relationship between mutation type and clinical presentation in EBP. The findings in this review (1) identify common clinical characteristics of EBP that may help in the assessment of patients with possible EBP; and (2) indicate that certain mutation carriers may have a higher likelihood of exhibiting particular phenotypes. In the case of potential diagnostic challenge, assessment for presence of common clinical findings as well as molecular testing may facilitate correct identification and prognostication.

Epidermolysis Bullosa Pruriginosa

Epidermolysis bullosa (EB) pruriginosa is a rare clinical subtype of dystrophic epidermolysis bullosa (DEB) that is characterized by intense pruritus resulting in hypertrophic, lichenified, prurigo-like plaques and nodules secondary to scratching. The variability in the age of onset, rarity of intact bullae, histologic ambiguities, and close resemblance to other conditions such as acquired inflammatory dermatoses may make diagnosis difficult for this unusual condition, for which fewer than 100 cases have been documented. In this report, we describe 3 cases of EB pruriginosa and review the current literature.

An incompletely penetrant novel mutation in COL7A1 causes epidermolysis bullosa pruriginosa and dominant dystrophic epidermolysis bullosa phenotypes in an extended kindred

Epidermolysis bullosa pruriginosa (EBP) is a rare subtype of dystrophic epidermolysis bullosa (DEB) characterized by intense pruritus, nodular or lichenoid lesions, and violaceous linear scarring, most prominently on the extensor extremities. Remarkably, identical mutations in COL7A1, which encodes an anchoring fibril protein present at the dermal-epidermal junction, can cause both DEB and EBP with either autosomal dominant or recessive inheritance. We present one family with both dystrophic and pruriginosa phenotypes of epidermolysis bullosa. The proband is a 19-year-old Caucasian woman who initially presented in childhood with lichenoid papules affecting her extensor limbs and intense pruritus consistent with EBP. Her maternal grandmother saw a dermatologist for similar skin lesions that developed without any known triggers at age 47 and mostly resolved spontaneously after approximately 10 years. The proband's younger brother developed a small crop of pruritic papules on his elbows, dorsal hands, knees, and ankles at age 13. Her second cousin once removed, however, reported a mild blistering disease without pruritus consistent with DEB. Genetic sequencing of the kindred revealed a single dominant novel intron 47 splice site donor G>A mutation, c.4668 + 1 G>A, which we predict leads to exon skipping. Incomplete penetrance is confirmed in her clinically unaffected mother, who carries the same dominant mutation. The wide diversity of clinical phenotypes with one underlying genotype demonstrates that COL7A1 mutations are incompletely penetrant and strongly suggests that other genetic and environmental factors influence clinical presentation.