Lisa Weibel

Parkes Weber syndrome, vein of Galen aneurysmal malformation, and other fast‐flow vascular anomalies are caused by RASA1 mutations

Capillary malformation‐arteriovenous malformation (CM‐AVM) is a newly recognized autosomal dominant disorder, caused by mutations in the RASA1 gene in six families. Here we report 42 novel RASA1 mutations and the associated phenotype in 44 families. The penetrance and de novo occurrence were high. All affected individuals presented multifocal capillary malformations (CMs), which represent the hallmark of the disorder. Importantly, one‐third had fast‐flow vascular lesions. Among them, we observed severe intracranial AVMs, including vein of Galen aneurysmal malformation, which were symptomatic at birth or during infancy, extracranial AVM of the face and extremities, and Parkes Weber syndrome (PKWS), previously considered sporadic and nongenetic. These fast‐flow lesions can be differed from the other two genetic AVMs seen in hereditary hemorrhagic telangiectasia (HHT) and in phosphatase and tensin homolog (PTEN) hamartomatous tumor syndrome. Finally, some CM‐AVM patients had neural tumors reminiscent of neurofibromatosis type 1 or 2. This is the first extensive study on the phenotypes associated with RASA1 mutations, and unravels their wide heterogeneity. Hum Mutat 29(7), 959–965, 2008.

Evaluation of methotrexate and corticosteroids for the treatment of localized scleroderma (morphoea) in children.

Background  Localized scleroderma (LS) or morphoea is often considered to be a benign self‐limiting condition confined to the skin and subcutaneous tissue. However, the course of the disease is unpredictable and severe functional and cosmetic disability may result. Drug treatment with systemic corticosteroids in combination with methotrexate has been reported to be beneficial in LS, but data in children is limited.

Linear morphoea follows Blaschko's lines

Background  The aetiology of morphoea (or localized scleroderma) remains unknown. It has previously been suggested that lesions of linear morphoea may follow Blaschko’s lines and thus reflect an embryological development. However, the distribution of linear morphoea has never been accurately evaluated.

Misdiagnosis and delay in referral of children with localized scleroderma

Summary Background  Localized scleroderma (LS) usually begins in childhood with a broad clinical spectrum and the diagnosis is often delayed.

Stigmatization Predicts Psychological Adjustment and Quality of Life in Children and Adolescents With a Facial Difference

OBJECTIVES This cross-sectional study assessed psychological adjustment and health-related quality of life (HRQOL) in children and adolescents with congenital or acquired facial differences and identified potential predictors of adjustment. METHODS Data were obtained from 88 children, ages 9 months to 16 years, by means of parent questionnaires (n = 86) and standardized interviews with children ≥7 years old (n = 31). Evaluation measures included the Child Behavior Checklist (CBCL), KIDSCREEN-27, TNO-AZL Preschool Quality of Life Questionnaire (TAPQOL), and Perceived Stigmatization Questionnaire. RESULTS Psychological adjustment, as measured by the CBCL, was within norms. Parent-reported HRQOL was good in preschool children. Parent- and self-reported HRQOL of participants 7-16 years old was impaired in several dimensions, including psychological well-being. Psychological adjustment (especially internalizing behavior problems) and HRQOL were predicted primarily by perceived stigmatization. CONCLUSIONS Identification of stigma experiences and appropriate support may be crucial to enhancing psychological adjustment and quality of life in children with facial disfigurement.

A pilot study showing pulsed-dye laser treatment improves localized areas of chronic atopic dermatitis

Background.  Eczematous skin changes overlying port‐wine stains have been reported to improve with pulsed‐dye laser (PDL) treatment. However, PDL has not as yet been evaluated for the treatment of atopic dermatitis (AD; eczema).

Next-Generation Sequencing of Nevus Spilus–Type Congenital Melanocytic Nevus: Exquisite Genotype–Phenotype Correlation in Mosaic RASopathies

TO THE EDITOR Nevus spilus is a descriptive term used to denote any cutaneous lesion with a cafe-au-lait macular background and superimposed on more pigmented areas. Small single nevus spilus are relatively common, and they have recently been described to be due to somatic activating HRAS mutations (Sarin et al., 2014). Larger superficial lesions with small superimposed junctional nevi in association with phakomatosis pigmentokeratotica have also been found to contain HRAS mutations (Groesser et al., 2013). However, another nevus spilus–type phenotype has also been well described in which large cafe-au-lait macules have superimposed lesions that are indistinguishable both clinically and histopathologically from medium/large congenital melanocytic nevi (CMN), exhibit a wide variety of colors and sizes (Schaffer et al., 2001a, 2001b), and continue to develop postnatally in many cases. This is termed nevus spilus–type CMN. In our experience, there may be delayed appearance of the cafe-au-lait background after birth, but the lesion is still usually predictable on the basis of clustering of many CMN in one anatomical area. Smaller separate lesions in the same individual are often indistinguishable clinically from cafe-au-lait macules, and are so faint that they can be easily missed (Figure 1). Our primary aim in this study was to look for the genetic basis of this defined phenotypic subset of CMN, in the context of the recent discovery that NRAS Q61K and Q61R mutations are the cause of most causes of multiple CMN (Kinsler et al., 2013b). In particular, we were interested in determining the mutation in the background macular portion of the nevus spilus–type CMN, working on the hypothesis that this could be the “first hit” in a two-hit model of nevogenesis. Figure 1 Clinical images of nevus spilus–type CMN in six different patients. The cafe-au-lait macule background is often invisible at birth. Two separate lesions are indicated in one patient. CMN, congenital melanocytic nevi. Written consent was ... These studies were approved by the appropriate Research Ethics Committee, written consent was taken from participants, and the Declaration of Helsinki Principles protocols were followed. A blood sample and skin biopsies of both the cafe-au-lait macule background and a banal superimposed CMN were taken from three children with large nevus spilus–type CMN, from a total of 17 patients from our combined practices (patients 5, 12, and 13 in Supplementary Table S1 online), and DNA was extracted directly by standard methods. Whole-exome sequencing using Nextera library preparation and an ABI Hi-Seq bioanalyser was undertaken on all three samples from two patients, and data were analyzed using an in-house pipeline designed for somatic mosaicism. The principal governing analysis was to look for a mutation present in the cafe-au-lait that was not present in the blood, and a further mutation in the CMN not present in the cafe-au-lait or the blood. In all, 1,991,478 variants were called automatically in the overlying CMN, affecting 20,693 genes. After filtering, the sequencing files of 133 variants in 39 genes were reviewed manually. A single mutation was found in the cafe-au-lait macule and the superimposed CMN, with no further mutation confirmed despite extensive analysis. These mutations were missense activating mutations in NRAS in the skin, absent from the blood, and this pattern of somatic mosaicism was confirmed in the third patient by Sanger sequencing. The mutations, however, are undescribed so far in typical CMN, being 1:115256528 c.183A>C p.Q61H (two patients, Figure 2) and 1:115258745 c.37G>C p.G13R. Both mutations have been described at a somatic level in non-CMN-related malignant melanoma (Forbes et al., 2008). Independently, a fourth patient (patient 17, Supplementary Table S1 online) had targeted exon capture of two skin samples, and analysis also revealed only the same NRAS p.Q61H mutation in both the cafe-au-lait macule and the superimposed CMN. Figure 2 Sequencing results showing NRAS mutation. Next-generation sequencing reads of blood (upper left), cafe-au-lait macule (upper centre), and overlying CMN (upper right) from the same patient showing mutation NRAS c.183A>C p.Q61H. Note the ... In conclusion, nevus spilus–type CMN are a phenotypically and genotypically distinct variant of CMN, and are phenotypically and genotypically distinct from nevus spilus maculosus and papulosus due to HRAS mutations (Groesser et al., 2013; Sarin et al., 2013). This further extends the exquisite mutation specificity of the newly characterized mosaic RASopathies. We found no evidence of a second mutation to explain the superimposed nevi on the macular background. It is, however, possible that there could be a mutation that does not appear pathogenic to us and to the analysis pipelines at the present time. Alternatively, there could be either a translocation that does not disrupt exonic DNA sequence, or a growth-promoting copy number change, although CMN have previously been documented as having few such changes on array comparative genomic hybridization (Bastian et al., 2002). The data at the moment suggest that only one sequence-level mutation occurs, and that these specific NRAS mutations are sufficient to cause cafe-au-lait macular pigmentation, which can lead to macroscopic nevus formation over time. Other experimental evidence supports that nevi can evolve in this way, from a cell or collection of cells in the skin not visible to the naked eye, as nevus cells have been found in normal skin in patients with acquired melanocytic nevi and typical CMN (Dadzie et al., 2008; Kinsler et al., 2013a). It is important to note for clinical management that malignant melanoma has been described in patients with nevus spilus–type CMN (Kinsler et al., 2009), and on current knowledge we would consider nevus spilus–type CMN patients at the same risk of malignancy as other genotypes. Similarly, although interestingly none of the 17 patients described here have neurological abnormalities on magnetic resonance imaging scan (Supplementary Table S1 online), these numbers are too small to draw any conclusions about a possible low risk of neurological phenotype. Management of nevus spilus–type CMN should therefore be the same as for other CMN.

Clinical expression and new SPINK5 splicing defects in Netherton syndrome: unmasking a frequent founder synonymous mutation and unconventional intronic mutations.

Netherton syndrome (NS) is a severe skin disease caused by loss-of-function mutations in SPINK5 (serine protease inhibitor Kazal-type 5) encoding the serine protease inhibitor LEKTI (lympho-epithelial Kazal type-related inhibitor). Here, we disclose new SPINK5 defects in 12 patients, who presented a clinical triad suggestive of NS with variations in inter- and intra-familial disease expression. We identified a new and frequent synonymous mutation c.891C>T (p.Cys297Cys) in exon 11 of the 12 NS patients. This mutation disrupts an exonic splicing enhancer sequence and causes out-of-frame skipping of exon 11. Haplotype analysis indicates that this mutation is a founder mutation in Greece. Two other new deep intronic mutations, c.283-12T>A in intron 4 and c.1820+53G>A in intron 19, induced partial intronic sequence retention. A new nonsense c.2557C>T (p.Arg853X) mutation was also identified. All mutations led to a premature termination codon resulting in no detectable LEKTI on skin sections. Two patients with deep intronic mutations showed residual LEKTI fragments in cultured keratinocytes. These fragments retained some functional activity, and could therefore, together with other determinants, contribute to modulate the disease phenotype. This new founder mutation, the most frequent mutation described in European populations so far, and these unusual intronic mutations, widen the clinical and molecular spectrum of NS and offer new diagnostic perspectives for NS patients.

Germline loss-of-function mutations in EPHB4 cause a second form of capillary malformation-arteriovenous malformation (CM-AVM2) deregulating RAS-MAPK signaling

Background: Most arteriovenous malformations (AVMs) are localized and occur sporadically. However, they also can be multifocal in autosomal-dominant disorders, such as hereditary hemorrhagic telangiectasia and capillary malformation (CM)-AVM. Previously, we identified RASA1 mutations in 50% of patients with CM-AVM. Herein we studied non-RASA1 patients to further elucidate the pathogenicity of CMs and AVMs. Methods: We conducted a genome-wide linkage study on a CM-AVM family. Whole-exome sequencing was also performed on 9 unrelated CM-AVM families. We identified a candidate gene and screened it in a large series of patients. The influence of several missense variants on protein function was also studied in vitro. Results: We found evidence for linkage in 2 loci. Whole-exome sequencing data unraveled 4 distinct damaging variants in EPHB4 in 5 families that cosegregated with CM-AVM. Overall, screening of EPHB4 detected 47 distinct mutations in 54 index patients: 27 led to a premature stop codon or splice-site alteration, suggesting loss of function. The other 20 are nonsynonymous variants that result in amino acid substitutions. In vitro expression of several mutations confirmed loss of function of EPHB4. The clinical features included multifocal CMs, telangiectasias, and AVMs. Conclusions: We found EPHB4 mutations in patients with multifocal CMs associated with AVMs. The phenotype, CM-AVM2, mimics RASA1-related CM-AVM1 and also hereditary hemorrhagic telangiectasia. RASA1-encoded p120RASGAP is a direct effector of EPHB4. Our data highlight the pathogenetic importance of this interaction and indicts EPHB4-RAS-ERK signaling pathway as a major cause for AVMs.

Validation of a protocol for the assessment of skin temperature and blood flow in childhood localised scleroderma

Background/purpose: Localised scleroderma (LS) is the most common form of scleroderma seen in children, and usually presents unilaterally. Infrared thermography (IRT) and laser Doppler (LD) have both been reported to be useful in assessing the active, inflammatory stage of LS. We developed and validated a protocol using these techniques for the assessment of unilateral LS activity in children.