Genetic Testing in CYLD Cutaneous Syndrome: An Update.

CYLD cutaneous syndrome (CCS) is an inclusive label for the inherited skin adnexal tumour syndromes Brooke-Spiegler Syndrome (BSS-OMIM 605041), familial cylindromatosis (FC - OMIM 132700) and multiple familial trichoepitheliomas (MFT-OMIM 601606). All three syndromes arise due to germline pathogenic variants in CYLD, a tumour suppressor gene (OMIM 605018). CCS is transmitted in an autosomal dominant pattern, and has variable expressivity, both of the three syndromic phenotypes, and of the severity of tumour burden. Age-related penetrance figures are not precisely reported. The first tumours typically appear during puberty and progressively accumulate through adulthood. Penetrance is typically high, with equal numbers of males and females affected. Genetic testing is important for confirmation of the clinical diagnosis, genetic counselling and family planning, including preimplantation diagnosis. Additionally, identified CCS patients may be eligible for future clinical trials of non-surgical pre-emptive interventions that aim to prevent tumour growth. In this update, we review the clinical presentations of germline and mosaic CCS. An overview of the germline pathogenic variant spectrum of patients with CCS reveals more than 100 single nucleotide variants and small insertions and deletions in coding exons, most frequently resulting in predicted truncation. In addition, a minority of patients have large deletions involving the CYLD gene, intronic pathogenic variants that affect splicing, or inversions. We discuss germline and somatic testing approaches. Somatic testing of tumour tissue, relevant in mosaic CCS, can reveal recurrently detected pathogenic variants when two or more tumours are tested. This can influence genetic testing of children, who may inherit this as a germline variant, and inform genetic counselling and prenatal diagnosis. Finally, we discuss testing technologies that are currently used, their benefits and limitations, and future directions for genetic testing in CCS.

Developmental cell programs are co-opted in inflammatory skin disease.

The skin confers biophysical and immunological protection through a complex cellular network established early in embryonic development. We profiled the transcriptomes of more than 500,000 single cells from developing human fetal skin, healthy adult skin, and adult skin with atopic dermatitis and psoriasis. We leveraged these datasets to compare cell states across development, homeostasis, and disease. Our analysis revealed an enrichment of innate immune cells in skin during the first trimester and clonal expansion of disease-associated lymphocytes in atopic dermatitis and psoriasis. We uncovered and validated in situ a reemergence of prenatal vascular endothelial cell and macrophage cellular programs in atopic dermatitis and psoriasis lesional skin. These data illustrate the dynamism of cutaneous immunity and provide opportunities for targeting pathological developmental programs in inflammatory skin diseases.

Defining the Skin Cellular Community Using Single-Cell Genomics to Advance Precision Medicine.

Single-cell genomics has revolutionized biological science, enabling high-resolution analysis of human tissues. The ability to demonstrate the role and function of distinct cell types comprising human tissues paves the way for a new understanding of cellular pathways, interactions, and future research directions. The skin, easily accessible and possessing a diverse and complex role in defending us both physically and immunologically from the outside world, lends itself ideally to single-cell genomics analysis. Here, we outline the benefits of single-cell RNA sequencing while also highlighting the challenges in achieving a meaningful result from its use. Key milestones relating to the study of skin in this way are introduced, covering both healthy and diseased states, and we discuss the potential promise of single-cell RNA sequencing to result in tangible medical advances, with a particular focus on precision medicine.

Evaluation of Flexible and Integrative Psychiatric Treatment Models in Germany-A Mixed-Method Patient and Staff-Oriented Exploratory Study.

Contrary to the practice in some countries, access to flexible and integrated forms of psychiatric care (FIT models) is limited in Germany. Several legislations have been introduced to improve this situation, notably the recent §64b (flexible and integrative treatment model; FIT64b) of the German Social Code, which allows for a capitation-based accounting of fees for services. The aim of this study was to explore the effects of FIT64b implementation on various stakeholders (patients, informal caregivers and staff) in 12 psychiatric hospital departments across Germany. Structural as well as quantitative and qualitative data are included, with integration of different methodological approaches. In all departments, the implementation of the new accounting system resulted into a relatively stable set of structural and processual changes where rigid forms of mainly inpatient care shifted to more flexible and integrated types of outpatient and outreach treatments. These changes were more likely to be perceived by patients and staff, and likewise received better evaluations, in those departments showing higher level or longer duration of implementation. Patients' evaluations, furthermore, were largely influenced by the advent of continuous forms of care, better accessibility, and by their degree of autonomy in steering of their services.

Understanding Inherited Cylindromas: Clinical Implications of Gene Discovery.

Cylindromas are cutaneous tumors first described in the medical literature over 150 years ago. They are now known to occur on an inherited basis as a result of mutations in the tumor-suppressor gene CYLD. The discovery of this gene has provided novel insights into this rare skin tumor syndrome. As well as enabling genetic counseling of affected patients, the knowledge of CYLD function has led to steps toward development of novel therapeutics, with CYLD-regulated signaling pathways as the target for this approach.

CYLD GeneticTesting for Brooke-Spiegler Syndrome, Familial Cylindromatosis and Multiple Familial Trichoepitheliomas.

The clinical presentation of multiple, rare, skin appendage tumours called cylindromas has been attributed to germline mutations in the tumour suppressor gene CYLD (OMIM 605018). Brooke-Spiegler Syndrome (BSS), familial cylindromatosis (FC) and multiple familial trichoepitheliomas (MFT) (OMIM #605041, #132700, #601606 respectively) differ due to the types of other skin appendage tumour seen together with cylindroma, such as spiradenoma and trichoepithelioma. Previously thought to be separate entities, they are now viewed as allelic variants with overlapping phenotypes, supported by mutation analysis of CYLD . The conditions display autosomal dominant inheritance and affected individuals develop multiple benign skin tumours most commonly on the head and neck. CYLD testing can be performed using PCR and Sanger sequencing for patients with: 1. Multiple cylindromas, spiradenomas or trichoepitheliomas. 2. A single cylindroma, spiradenoma or trichoepithelioma and an affected first-degree relative with any of these tumours. 3. An asymptomatic family member at 50% risk with a known mutation in the family.

3q26.33-3q27.2 microdeletion: a new microdeletion syndrome?

We describe three unrelated patients of European descent carrying an overlapping 3q26.33-3q27.2 microdeletion who share common clinical features: neonatal hypotonia, severe feeding problems, specific facial features, abnormal dentition, recurrent upper airways infections, developmental delay and severe growth impairment. One of the patients carries a smaller deletion and presents a milder phenotype. We propose that 3q26.33-3q27.2 microdeletion may represent a novel condition caused by the haploinsufficiency of dosage sensitive genes, several of which are involved in brain development.