Management of congenital ichthyoses: European guidelines of care, part one

These guidelines for the management of congenital ichthyoses have been developed by a multidisciplinary group of European experts following a systematic review of the current literature, an expert conference held in Toulouse in 2016 and a consensus on the discussions. They summarize evidence and expert-based recommendations and are intended to help clinicians with the management of these rare and often complex diseases. These guidelines comprise two sections. This is part one, covering topical therapies, systemic therapies, psychosocial management, communicating the diagnosis and genetic counselling.

Novel clinical and molecular findings in Spanish patients with naevoid basal cell carcinoma syndrome

BACKGROUND

Naevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by developmental alterations and multiple basal cell carcinomas. Mutations in PTCH1, which encodes a membrane receptor for Sonic Hedgehog, are associated with the development of the disease. Most of them produce a truncated protein, which is unable to suppress Smoothened protein and continuously activates the downstream pathway.

OBJECTIVES

We aimed to characterize 22 unrelated Spanish patients with NBCCS, the largest cohort with Gorlin syndrome reported to date in Spain.

METHODS

Genomic analysis of PTCH1 was performed in patients with NBCCS and controls, and mutations were analysed using bioinformatics tools.

RESULTS

We report for the first time two young patients, one each with uterus didelphys and ganglioneuroma, within the context of NBCCS. One patient showing a severe phenotype of the disease had developed basal cell carcinomas since childhood. Sanger sequencing of PTCH1 in this cohort identified 17 novel truncating mutations (11 frameshift, five nonsense and one mutation affecting an exon-intron splice site) and two novel missense mutations that were predicted to be pathogenic. The patients showed great clinical variability and inconsistent genotype-phenotype correlation, as seen in relatives carrying similar mutations.

CONCLUSIONS

This study contributes to increase the pool of clinical manifestations of NBCCS, as well as increasing the number of pathogenic mutations identified in PTCH1 predisposing to the condition. The inconsistencies found between phenotype and genotype suggest the involvement of other modifying factors, genetic, epigenetic or environmental.

[Update on the treatment of RASopathies]

INTRODUCTION

The term 'RASopathies' covers a series of diseases that present mutations in the genes that code for the proteins of the RAS/MAPK pathway. These diseases include neurofibromatosis type 1, Noonan syndrome, Legius syndrome, LEOPARD syndrome, Costello syndrome and cardiofaciocutaneous syndrome. Involvement of the RAS/MAPK pathway not only increases predisposition to develop tumours, but also determines the presence of phenotypic anomalies and alterations in learning processes.

AIM

To review the use of therapeutic strategies with mechanisms that have a selective action on RASopathies.

DEVELOPMENT

The fact that the RAS pathway is involved in a third of all neoplasms has led to the development and study of different drugs at this level. Some of these pharmaceutical agents have been tested in RASopathies, mainly in neurofibromatosis type 1. Here we analyse the use of different antitarget treatments: drugs that act on the membrane receptors, such as tyrosine kinase inhibitors, in the mTOR pathway or MEK inhibitors. These latter have shown potential benefits in recent studies conducted on different RASopathies.

CONCLUSIONS

Today, thanks to the results from the first studies conducted with MEK inhibitor based mainly on animal models, a number of promising clinical trials are being carried out.

Ulcerated sclerotic giant congenital melanocytic naevus: case report and review of the literature

We report a case of a white girl with an ulcerated giant congenital melanocytic naevus that initially had a hard, stony consistency but in which the pigmentation and the induration are progressively vanishing. Very few cases of this variant of GCMN, known as sclerodermoid GCMN or desmoplastic hypopigmented hairless naevus, have been reported to date, and clinical evolution seems to be heterogeneous. We review the published cases and propose the term 'sclerotic hypopigmented GCMN as a common descriptor of this type of congenital melanocytic naevus.

Congenital multiple clustered dermatofibroma

Multiple clustered dermatofibroma (MCD) is a rare tumour which usually appears during the first and second decades of life. We report a man in whom the MCD was congenital, although during the first few years of his second decade it extended to involve a broad zone on the left hip, gluteal region and upper thigh.

Juvenile xanthogranuloma

Juvenile xanthogranuloma (JXG) is a benign, self-healing disorder characterized by solitary or multiple yellow-red nodules on the skin and, occasionally, in other organs. It is predominantly a disease of infancy or early childhood, although adults may also be affected. Histologically, JXG represents an accumulation of histiocytes lacking Birbeck granules (non-Langerhans cells), which can be differentiated from Langerhans cells by specific staining techniques. Affected persons have normal lipid metabolism. JXG is therefore classified as a normolipemic non-Langerhans cell histiocytosis. The patient's general health is not impaired and, in the absence of associated conditions, the prognosis is excellent. Diagnosis is readily made in typical cases, but may be more difficult in unusual variants.