Multiple Self-Healing Squamous Epithelioma (MSSE): A Digenic Trait Associated with Loss of Function Mutations in TGFBR1 and Variants at a Second Linked Locus on the Long Arm of Chromosome 9

Multiple Self-Healing Squamous Epithelioma and Loeys-Dietz syndrome: a single TGFBR1 variant, two phenotypes in one patient

Multiple Self-Healing Squamous Epithelioma of Ferguson-Smith (OMIM 132800) is a syndrome increasing the risk of developing keratoacanthomas, which are locally aggressive skin tumours. Loeys-Dietz syndrome is a connective tissue disease characterised by arterial fragility. There is no increased risk of skin tumours classically described.Both phenotypes have been associated with a different pathogenic variant of the TGFBR1 gene involved in the TGFbeta signalling pathway. We present the case of a patient with both phenotypes. This appears to be caused by a single likely pathogenic variant within TGFBR1: c.1421G>A (p.Cyst474Tyr) in the protein domain of the serine-threonine protein kinase.This is the fourth reported case exhibiting this dual clinical presentation with a single genetic variant in this same region.

Multiple Keratoacanthomas Associated with Genetic Syndromes: Narrative Review and Proposal of a Diagnostic Algorithm

Keratoacanthoma (KA) is a relatively common, fast-growing epithelial tumour, with characteristic behaviour and clinical variability. Although it appears as a solitary lesion in a majority of cases, multiple KAs do occur, secondary to skin exposure to ultraviolet radiation, chemical carcinogens or certain medications, but may also be associated with various genetic syndromes. Thus, multiple KAs may serve as an early clinical alarm sign. Prompt diagnosis of the underlying cause and identification of the mechanism of development are critical for the secondary prevention of associated organ disorders or neoplasias, the improvement of patient quality of life and familial counselling. Although research in this field has seen important progress in the last few years, there are still many pathogenic processes that have not been elucidated. Additionally, the literature on this topic is limited to individual case reports and small case series, making it difficult for clinicians to parse available data and select the essential information. Therefore, this work aims to review current knowledge, summarizing existing studies, with focus on multiple KAs associated with genetic syndromes, and proposes a diagnostic algorithm for these rare cases to help guide clinicians in their practice. Lastly, we aim to highlight the main gaps in understanding the underlying mechanisms and suggest further research avenues.

Coexistence of multiple self-healing squamous epithelioma and features of Loeys-Dietz syndrome caused by a pathogenic missense variant in the kinase domain of TGFBR1

Multiple self-healing squamous epithelioma (MSSE) is characterized by development of multiple self-healing skin tumours that may affect any part of the body. Spontaneous resolution may take several months leaving pitted scars. Most pathogenic variants in patients with MSSE are truncating variants distributed throughout the gene or missense variants in the receptor domain of TGFBR1. Missense variants in the kinase domain of TGFBR1 cause Loeys–Dietz syndrome (LDS), which is a connective tissue disorder associated with increased risk of aortic and arterial aneurysms and dissection. We report the coexistence of MSSE and features of LDS caused by a pathogenic missense variant in the kinase domain of TGFBR1.

TGF-β signaling in health, disease, and therapeutics

Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.

A case of multiple self-healing squamous epitheliomas of Ferguson-Smith in a patient on systemic immunosuppression for rheumatoid arthritis

An 82-year-old man was referred with an 18-month history of multiple enlarging ulcerated, nontender nodules on a background of a 30-year history of multiple self-healing squamous epitheliomas of Ferguson-Smith (MSSE-FS). Historically, his lesions regressed spontaneously within a few months of their appearance. At the time of presentation, he was taking sulfasalazine for rheumatoid arthritis (RA), and at higher doses, he noted a deterioration in his MSSE-FS. After discussion with rheumatology, sulfasalazine was stopped after which his lesions rapidly regressed and have now mostly healed; however, his RA has subsequently deteriorated and further treatment options are still being considered.

Familial multiple discoid fibromas is linked to a locus on chromosome 5 including the FNIP1 gene

Previously, we reported a series of families presenting with trichodiscomas, inherited in an autosomal dominant pattern. The phenotype was named familial multiple discoid fibromas (FMDF). The genetic cause of FMDF remained unknown so far. Trichodiscomas are skin lesions previously reported to be part of the same spectrum as the fibrofolliculoma observed in Birt-Hogg-Dubé syndrome (BHD), an inherited disease caused by pathogenic variants in the FLCN gene. Given the clinical and histological differences with BHD and the exclusion of linkage with the FLCN locus, the phenotype was concluded to be distinct from BHD. We performed extensive clinical evaluations and genetic testing in ten families with FMDF. We identified a FNIP1 frameshift variant in nine families and genealogical studies showed common ancestry for eight families. Using whole exome sequencing, we identified six additional rare variants in the haplotype surrounding FNIP1, including a missense variant in the PDGFRB gene that was found to be present in all tested patients with FMDF. Genome-wide linkage analysis showed that the locus on chromosome 5 including FNIP1 was the only region reaching the maximal possible LOD score. We concluded that FMDF is linked to a haplotype on chromosome 5. Additional evaluations in families with FMDF are required to unravel the exact genetic cause underlying the phenotype. When evaluating patients with multiple trichodisomas without a pathogenic variant in the FLCN gene, further genetic testing is warranted and can include analysis of the haplotype on chromosome 5.

Detection of copy number variants associated with late-onset conditions in ~16 200 pregnancies: parameters for disclosure and pregnancy outcome

BACKGROUND

Copy number variants (CNVs) associated with late-onset medical conditions are rare but important secondary findings in chromosomal microarray analysis (CMA) performed during pregnancy. Here, we critically review the cases at two tertiary centres to assess the criteria which guide the disclosure of such findings and develop a disclosure decision tool (DDT) aimed at facilitating disclosure decision. Parental decisions on receiving CNVs associated with risks for late-onset conditions were also recorded.

METHODS

Prenatal CMAs in Hadassah and Shaare Zedek Medical Centers from November 2013 to October 2021 were reviewed for CNVs associated with late-onset conditions. The DDT proposed uses a five-parameter scoring system, which considers the severity, median age of onset, penetrance, understanding of genotype-phenotype correlation and actionability of the finding.

RESULTS

Out of 16 238 prenatal CMAs, 16 (0.1%) harboured CNVs associated with late-onset conditions, 15 of which were disclosed. Outcome information was available on 13 of the 16 pregnancies, all of which continued to delivery.

CONCLUSIONS

Our suggested DDT will help clinicians to quantitatively weigh the variables associated with CNVs of this type and arrive at a well thought out clinical decision regarding disclosure. Although the prevalence of late-onset conditions as a major finding in the prenatal setup is low, it is expected to rise with the increasing use of non-invasive CMA testing and whole exome and genome sequencing.

Overview of familial syndromes with increased skin malignancies

The vast majority of skin cancers can be classified into two main types: melanoma and keratinocyte carcinomas. The most common keratinocyte carcinomas include basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Multiple familial syndromes have been identified that can increase the risk of developing SCC, BCC, and/or melanoma. The major syndromes include oculocutaneous albinism for SCC, basal cell nevus syndrome for BCC, familial atypical multiple mole-melanoma syndrome, and hereditary breast and ovarian cancer syndrome for melanoma. In addition, familial syndromes that can predispose individuals to all three major skin cancers include xeroderma pigmentosum and Li-Fraumeni syndrome. This review highlights the epidemiology, risk factors, pathogenesis, and etiology of the major and minor syndromes to better identify and manage these conditions. Current investigational trials in genomic medicine are making their way in revolutionizing the clinical diagnosis of these familial syndromes for earlier preventative measures and improvement of long-term prognosis in these patients.

Multiple keratoacanthomas of Ferguson-Smith type

We report a case of a 41-year-old male patient with no family history, presented with extensive multiple keratoacanthomas with disfiguring scars. The diagnosis of a sporadic form of Ferguson-Smith syndrome was made. Treatment with acitretin showed a marked response. Recognizing this syndrome is crucial. Early treatment helps avoid scar formation.

Non-Melanoma Skin Cancers and Other Cutaneous Manifestations in Bone Marrow Failure Syndromes and Rare DNA Repair Disorders

Although most non-melanoma skin cancers are felt to be sporadic in origin, these tumors do play a role in several cancer predisposition syndromes. The manifestations of skin cancers in these hereditary populations can include diagnosis at extremely early ages and/or multiple primary cancers, as well as tumors at less common sites. Awareness of baseline skin cancer risks for these individuals is important, particularly in the setting of treatments that may compromise the immune system and further increase risk of cutaneous malignancies. Additionally, diagnosis of these disorders and management of non-cutaneous manifestations of these diseases have profound implications for both the patient and their family. This review highlights the current literature on the diagnosis, features, and non-melanoma skin cancer risks associated with lesser-known cancer predisposition syndromes, including bone marrow failure disorders, genomic instability disorders, and base excision repair disorders.