Clinical practice guidelines for laboratory diagnosis of epidermolysis bullosa

This guideline were initiated by DEBRA International; financial support was provided by DEBRA Austria. The generous assistance of Rebecca Bodan, Lisa Brains, Sharon Cassidy and Kelsey Townsend-Miller is gratefully acknowledged in providing patient or lay input into this guideline. The authors acknowledge the guidance of Kattya Mayre-Chilton (DEDRA International). Johann Bauer (Paracelsus University and EB House, Salzburg, Austria), Christine Bodemer (Hôpital Universitaire Necker, Paris, France), Judith Fischer (Institute of Human Genetics, University of Freiburg, Germany), Jemima Mellerio (St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, U.K.), Francis Palisson (Universidad del Desarrollo and DEBRA, Chile), Eli Sprecher (Department of Dermatology, Tel Aviv Sourasky Medical Center, Israel) and Jouni Uitto, Leila Youssefian and Hassan Vahidnezhad (all from the Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, PA, U.S.A.) are acknowledged as reviewers

Novel and recurrent variants of ATP2C1 identified in patients with Hailey-Hailey disease

Hailey-Hailey disease (HHD) is a rare, late-onset autosomal dominant genodermatosis characterized by blisters, vesicular lesions,crusted erosions, and erythematous scaly plaques predominantly in intertriginous regions. HHD is caused by ATP2C1 mutations. About 180 distinct mutations have been identified so far; however, data of only few cases from Central Europe are available. The aim was to analyze the ATP2C1 gene in a cohort of Polish HHD patients. A group of 18 patients was enrolled in the study based on specific clinical symptoms. Mutations were detected using Sanger or next generation sequencing. In silico analysis was performed by prediction algorisms and dynamic structural modeling. In two cases, mRNA analysis was performed to confirm aberrant splicing. We detected 13 different mutations, including 8 novel, 2 recurrent (p.Gly850Ter and c.325-3 T > G), and 6 sporadic (c.423-1G > T, c.899 + 1G > A, p.Leu539Pro, p.Thr808TyrfsTer16, p.Gln855Arg and a complex allele: c.[1610C >G;1741 + 3A > G]). In silico analysis shows that all novel missense variants are pathogenic or likely pathogenic. We confirmed pathogenic status for two novel variants c.325-3 T > G and c.[1610C > G;1741 + 3A > G] by mRNA analysis. Our results broaden the knowledge about genetic heterogeneity in Central European patients with ATP2C1 mutations and also give further evidence that careful and multifactorial evaluation of variant pathogenicity status is essential

Amelioration of junctional epidermolysis bullosa due to exon skipping

Mutations in the COL17A1 gene lead to the genetic blistering disorder junctional epidermolysis bullosa generalized intermediate type (JEB-gen-intermed). Antisense oligonucleotide-mediated exon skipping is a strategy that aims to skip the mutation-containing exon and thereby produce a smaller but functional protein. COL17A1 is an interesting candidate, as 53 of the 55 exons (96%) can be skipped without disturbing the reading frame. Information on the functionality of the shortened protein product is important in order to obtain support for this therapeutic strategy. Here we report a patient with JEB-gen-intermed with amelioration of the phenotype due to exon 49 skipping by two distinct mechanisms premature termination codon-induced exon skipping and revertant mosaicism both of which induced skipping of the same exon. The patient was compound heterozygous for two inherited COL17A1 mutations, a frameshift mutation in exon 18 (c.1490_1491delinsT, p.Ala497Valfs*23) and a nonsense mutation in exon 49 (c.3487G>T, p.Glu1163Ter). Upon clinical examination, skin patches were found that were resistant to blister formation. In these patches, naturally corrected cells were present that harboured an additional splice-site mutation, c.3419-1G>T, resulting in skipping of the mutation-containing exon 49. This natural gene therapy phenomenon shows that type XVII collagen with residues 1140-1169 deleted is largely functional. In addition, in affected skin cells a low level of exon 49 skipping was observed. Our results support the notion that skipping of a mutated in-frame exon in COL17A1 ameliorates the phenotype

Disease-specific databases: why we need them and some recommendations from the Human Variome Project Meeting, May 28, 2011

The need for Locus-Specific Databases, with disease-specific experts and curators, is an essential ingredient in a process to enable the benefits of the advances in sequencing and mutational analysis to be realized across the genome. Next generation sequencing provides both astounding opportunities and challenges, especially for genetic counsellors. An approach coordinated at a genome wide, international level, supported by well-organized disease-specific respected organizations is a model most likely to be successful, but committed resourceful professionals working in local poorly resourced environments can make valuable contributions that can grow. Bioinformatic tools to sift and integrate multiple domains of information are being developed, and play a major part in meeting the challenges. Regulation of providers, including a requirement for them to submit mutational information to central databases, also should assist to reach the goals needed to realize the opportunities. There is also a need to agree on governance of Locus-Specific Databases (LSDBs) at an international level, and for adequate international funding to support this need, to ensure humanity reaps the benefits of the current molecular genetic revolution. The Human Variome Project offers this, working also with the other major initiatives with similar objectives. This report concludes with Recommendations for the Human Variome Project stemming from the presentations and discussions at the meeting.Heather J. Howard, Arthur Beaudet, Vera Gil-da-Silva Lopes, Mike Lyne, Graeme Suthers, Peter Van den Akker, Katarzyna Wertheim-Tysarowska, Patrick Willems, and Finlay Macra