Blue Rubber Bleb Nevus (BRBN) Syndrome Is Caused by Somatic TEK (TIE2) Mutations.

Blue rubber bleb nevus syndrome (Bean syndrome) is a rare, severe disorder of unknown cause, characterized by numerous cutaneous and internal venous malformations; gastrointestinal lesions are pathognomonic. We discovered somatic mutations in TEK, the gene encoding TIE2, in 15 of 17 individuals with blue rubber bleb nevus syndrome. Somatic mutations were also identified in five of six individuals with sporadically occurring multifocal venous malformations. In contrast to common unifocal venous malformation, which is most often caused by the somatic L914F TIE2 mutation, multifocal forms are predominantly caused by double (cis) mutations, that is, two somatic mutations on the same allele of the gene. Mutations are identical in all lesions from a given individual. T1105N-T1106P is recurrent in blue rubber bleb nevus, whereas Y897C-R915C is recurrent in sporadically occurring multifocal venous malformation: both cause ligand-independent activation of TIE2, and increase survival, invasion, and colony formation when expressed in human umbilical vein endothelial cells.

Expanding the clinical spectrum of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis due to FAM111B mutations.

BACKGROUND: Hereditary Fibrosing Poikiloderma (HFP) with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP [MIM 615704]) is a very recently described entity of syndromic inherited poikiloderma. Previously by using whole exome sequencing in five families, we identified the causative gene, FAM111B (NM_198947.3), the function of which is still unknown. Our objective in this study was to better define the specific features of POIKTMP through a larger series of patients. METHODS: Clinical and molecular data of two families and eight independent sporadic cases, including six new cases, were collected. RESULTS: Key features consist of: (i) early-onset poikiloderma, hypotrichosis and hypohidrosis; (ii) multiple contractures, in particular triceps surae muscle contractures; (iii) diffuse progressive muscular weakness; (iv) pulmonary fibrosis in adulthood and (v) other features including exocrine pancreatic insufficiency, liver impairment and growth retardation. Muscle magnetic resonance imaging was informative and showed muscle atrophy and fatty infiltration. Histological examination of skeletal muscle revealed extensive fibroadipose tissue infiltration. Microscopy of the skin showed a scleroderma-like aspect with fibrosis and alterations of the elastic network. FAM111B gene analysis identified five different missense variants (two recurrent mutations were found respectively in three and four independent families). All the mutations were predicted to localize in the trypsin-like cysteine/serine peptidase domain of the protein. We suggest gain-of-function or dominant-negative mutations resulting in FAM111B enzymatic activity changes. CONCLUSIONS: HFP with tendon contractures, myopathy and pulmonary fibrosis, is a multisystemic disorder due to autosomal dominant FAM111B mutations. Future functional studies will help in understanding the specific pathological process of this fibrosing disorder.

Filaggrin-stratified transcriptomic analysis of pediatric skin identifies mechanistic pathways in patients with atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD; eczema) is characterized by a widespread abnormality in cutaneous barrier function and propensity to inflammation. Filaggrin is a multifunctional protein and plays a key role in skin barrier formation. Loss-of-function mutations in the gene encoding filaggrin (FLG) are a highly significant risk factor for atopic disease, but the molecular mechanisms leading to dermatitis remain unclear. OBJECTIVE: We sought to interrogate tissue-specific variations in the expressed genome in the skin of children with AD and to investigate underlying pathomechanisms in atopic skin. METHODS: We applied single-molecule direct RNA sequencing to analyze the whole transcriptome using minimal tissue samples. Uninvolved skin biopsy specimens from 26 pediatric patients with AD were compared with site-matched samples from 10 nonatopic teenage control subjects. Cases and control subjects were screened for FLG genotype to stratify the data set. RESULTS: Two thousand four hundred thirty differentially expressed genes (false discovery rate, P < .05) were identified, of which 211 were significantly upregulated and 490 downregulated by greater than 2-fold. Gene ontology terms for "extracellular space" and "defense response" were enriched, whereas "lipid metabolic processes" were downregulated. The subset of FLG wild-type cases showed dysregulation of genes involved with lipid metabolism, whereas filaggrin haploinsufficiency affected global gene expression and was characterized by a type 1 interferon-mediated stress response. CONCLUSION: These analyses demonstrate the importance of extracellular space and lipid metabolism in atopic skin pathology independent of FLG genotype, whereas an aberrant defense response is seen in subjects with FLG mutations. Genotype stratification of the large data set has facilitated functional interpretation and might guide future therapy development.

Rapidly involuting congenital hemangioma with pustules: two cases.

Rapidly involuting congenital hemangiomas (RICHs) are rare tumors that usually present as well-defined bluish or violaceous plaques or tumors with scattered telangiectasias and central or peripheral pallor. We report two previously unreported cases of RICH with associated pustules.

Use of systemic corticosteroids in management of a large congenital haemangioma of the scalp.

Congenital haemangiomas are rare and are estimated to have a combined incidence of less than 3% of all infantile haemangiomas. They are fully grown at birth, having undergone their proliferative phase in utero. Congenital hemangiomas can present at birth or in some cases can be detected antenatally on imaging. In the majority of patients no therapeutic intervention is required. Congenital hemangiomas also differ from infantile hemangiomas by staining negatively with GLUT1 antibody. They fall into two major subtypes: rapidly involuting congenital hemangiomas (RICHs) and noninvoluting congenital hemangiomas (NICHs). Here we describe a case of RICH detected antenatally on ultrasound imaging. This lesion caused significant complications in the postnatal period due to the bulk of the lesion and the presence of incipient ulceration with the risk of possible catastrophic hemorrhage. A therapeutic trial of oral corticosteroid was commenced in an effort to accelerate involution due to the significant risk associated with other possible treatment modalities such as embolization or surgical intervention.

PHACE syndrome: MRI of intracerebral vascular anomalies and clinical findings in a series of 12 patients.

BACKGROUND: PHACE (posterior fossa defects, haemangioma, arterial anomalies, coarctation of the aorta and cardiac defects, eye abnormalities) syndrome describes a constellation of abnormalities that can occur in association with segmental craniofacial infantile haemangioma. OBJECTIVE: To report the spectrum of clinical and imaging abnormalities seen in a cohort of children. MATERIALS AND METHODS: A retrospective review of the clinical and imaging records of all patients diagnosed with PHACE syndrome between 1998 and 2009 was performed. Information sought included patient demographics, craniofacial segments involved, imaging findings and other extracutaneous abnormalities. RESULTS: Twelve patients were diagnosed with PHACE syndrome over 11 years. All patients had a segmental craniofacial haemangioma. Involved facial segments, in order of frequency, were frontotemporal (12), maxillary (8), mandibular (5) and frontonasal (1). The most common extracutaneous abnormalities were neurovascular anomalies (10), with many patients having multiple anomalies. The spectrum of arterial anomalies ranged from hypoplasia (9) to ectasia (3), anomalous origin/course (2) and persistent fetal anastomosis (2). Other anomalies found included cardiac anomalies (3), coarctation of the aorta (2), posterior fossa malformations (1) and sternal region anomalies (1). CONCLUSION: Intracranial anomalies are the most common extracutaneous feature of PHACE syndrome. The contribution of the radiologist in the recognition of such anomalies is important for the diagnosis of PHACE syndrome.

Care of epidermolysis bullosa in Ireland.

Advances in the medical care of epidermolysis bullosa (EB) have led to the development of National Service Centers for EB in many countries worldwide. The exemplary model of care to children and adults with EB in the United Kingdom, combined with the knowledge that people with EB were travelling to the United Kingdom for treatment, encouraged the development of the Irish national service. Dystrophic Epidermolysis Bullosa Research Association of Ireland, founded in 1988 played a pivotal role in this development.

Mediastinal and neck kaposiform hemangioendothelioma: report of three cases.

Kaposiform hemangioendothelioma is an aggressive vascular tumor, named for its striking histologic resemblance to Kaposi sarcoma and locally invasive growth. Mortality is high, and ranges from 10% to 24% for all kaposiform hemangioendothelioma lesions, with a significantly higher mortality for deep soft-tissue or visceral lesions occurring in infants less than 6 months. Mediastinal and neck kaposiform hemangioendothelioma in particular merit special discussion, as involvement of these critical anatomic locations results in significant site-specific therapeutic challenges due to invasion of vital structures, inherent delays in establishing histopathologic confirmation, and difficulties in monitoring disease status. We report our experience with three cases of mediastinal and neck kaposiform hemangioendothelioma, emphasizing the unique diagnostic and management challenges, variable response to treatment and outcome of this anatomic variant of kaposiform hemangioendothelioma.

Response to IL-1-receptor antagonist in a child with familial cold autoinflammatory syndrome.

Familial cold auto-inflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurologic, cutaneous, articular syndrome are related disorders associated with mutations in the CIAS1 gene. They appear to represent a continuum of one disease characterized by IL-1-mediated inflammation. Until recently, these conditions have been difficult to treat; however, with the advent of IL-1-receptor antagonist therapy, many reports of successful treatment of patients with these autoinflammatory diseases have emerged in the past 2 years. We describe an 8-year-old girl, diagnosed with Familial cold auto-inflammatory syndrome, confirmed by presence of a novel CIAS1 mutation, who was refractory to symptomatic treatment. As frequent attacks of urticaria and associated arthralgia had a debilitating effect on the child's lifestyle, a trial of IL-1-receptor antagonist (anakinra) was instituted. Dramatic sustained clinical improvement was evident within days and serum amyloid and C-reactive protein levels normalized within a month. Although several authors have reported successful use of this agent in children with chronic infantile neurologic, cutaneous, articular syndrome, we believe ours is the first report of successful treatment with anakinra in a young child with familial cold auto-inflammatory syndrome.

ABCA12 is the major harlequin ichthyosis gene.

Harlequin ichthyosis (HI) is the most severe form of autosomal-recessive, congenital ichthyosis. Affected infants have markedly impaired barrier function and are more susceptible to infection. Abnormalities in the localization of epidermal lipids as well as abnormal lamellar granule formation are features of HI skin. Previously, we and others have shown that mutations in the ABCA12 gene encoding an adenosine triphosphate-binding cassette (ABC) transporter underlie the skin disease HI. In this study, we have sequenced the ABCA12 gene in an additional 14 patients and show that all contain mutations, with the majority being either nonsense substitution or frameshift mutations. Eleven HI patients had bi-allelic ABCA12 mutations, whereas in the remaining three HI patients in this study, ABCA12 mutations were detected on only one allele by sequencing. In addition, the one patient from the previous study where no sequence mutations were detected was screened for heterozygous deletions. A combination of oligonucleotide arrays, multiplex PCR analysis and single-nucleotide polymorphism genotyping revealed a heterozygous intragenic deletion in exon 8. These mutation data establish ABCA12 as the major HI gene.

Prevalent and rare mutations in the gene encoding filaggrin cause ichthyosis vulgaris and predispose individuals to atopic dermatitis.

Mutations in the filament aggregating protein (filaggrin) gene have recently been identified as the cause of the common genetic skin disorder ichthyosis vulgaris (IV), the most prevalent inherited disorder of keratinization. The main characteristics of IV are fine-scale on the arms and legs, palmar hyperlinearity, and keratosis pilaris. Here, we have studied six Irish families with IV for mutations in filaggrin. We have identified a new mutation, 3702delG, in addition to further instances of the reported mutations R501X and 2282del4, which are common in people of European origin. A case of a 2282del4 homozygote was also identified. Mutation 3702delG terminates protein translation in filaggrin repeat domain 3, whereas both recurrent mutations occur in repeat 1. These mutations are semidominant: heterozygotes have an intermediate phenotype most readily identified by palmar hyperlinearity and in some cases fine-scale and/or keratosis pilaris, whereas homozygotes or compound heterozygotes generally have more marked ichthyosis. Interestingly, the phenotypes of individuals homozygous for R501X, 2282del4, or compound heterozygous for R501X and 3702delG, were comparable, suggesting that mutations located centrally in the filaggrin repeats are also pathogenic.