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Telangiectases and arteriovenous malformations (AVMs) are the characteristic lesions of Hereditary Hemorrhagic Telangiectasia (HHT). Somatic second-hit loss-of-function variations in the HHT causative genes, ENG and ACVRL1 , have been described in dermal telangiectasias. It is unclear if somatic second-hit mutations also cause the formation of AVMs and nasal telangiectasias in HHT. To investigate the genetic mechanism of AVM formation in HHT, we evaluated multiple affected tissues from fourteen individuals. DNA was extracted from fresh/frozen tissue of 15 nasal telangiectasia, 4 dermal telangiectasia, and 9 normal control tissue biopsies, from nine unrelated individuals with HHT. DNA from six formalin-fixed paraffin-embedded (FFPE) AVM tissues (brain, lung, liver, and gallbladder) from five individuals was evaluated. A 736 vascular malformation and cancer gene next-generation sequencing (NGS) panel was used to evaluate these tissues down to 1% somatic mosaicism. Somatic second-hit mutations were identified in three in four AVM biopsies (75%) or half of the FFPE (50%) samples, including the loss of heterozygosity in ENG in one brain AVM sample, in which the germline mutation occurred in a different allele than a nearby somatic mutation (both are loss-of-function mutations). Eight of nine (88.9%) patients in whom telangiectasia tissues were evaluated had a somatic mutation ranging from 0.68 to 1.96% in the same gene with the germline mutation. Six of fifteen (40%) nasal and two of four (50%) dermal telangiectasia had a detectable somatic second hit. Additional low-level somatic mutations in other genes were identified in several telangiectasias. This is the first report that nasal telangiectasias and solid organ AVMs in HHT are caused by very-low-level somatic biallelic second-hit mutations.

Telangiectasia-ectodermal dysplasia-brachydactyly-cardiac anomaly (TEBC) syndrome is a rare autosomal dominant condition, recently linked to the protein kinase D1 (PRKD1) gene. The phenotype of TEBC remains incomplete at this point. Our aim is to improve the characterization of the clinical and molecular aspects of the TEBC syndrome. We report on the 8th patient carrying a heterozygous de novo variation of PRKD1 c.2134G > A, p. (Val712Met) identified by trio exome sequencing. The proband presents with partial atrioventricular septal defect, brachydactyly, ectodermal dysplasia, telangiectasia that developed in childhood, intellectual disability with microcephaly, multicystic renal dysplasia and moderate hormonal resistance. In view of this 8th description and review of the literature, it appears that neurodevelopmental disorders and microcephaly are frequently associated with PRKD1 missense variants, adding to the four main clinical signs described initially in the TEBC syndrome. Further descriptions are required to confirm the observed endocrine and kidney abnormalities. This should contribute to a more comprehensive understanding of the phenotypic spectrum and may help establish genotype-phenotype correlations. In the context of genotype-first strategy, accurate patient descriptions are fundamental. Characterization of specific syndromic associations is essential for variant interpretation support and patient follow-up, even in very rare diseases, such as the TEBC syndrome., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Capillary malformations (CMs) are the most common type of vascular anomalies, affecting around 0.3% of newborns. They are usually caused by somatic pathogenic variants in GNAQ or GNA11. PIK3CA and PIK3R1, part of the phosphoinositide 3-kinase-protein kinase B-mammalian target of rapamycin pathway, are mutated in fainter CMs such as diffuse CM with overgrowth and megalencephaly CM. In this study, we present two young patients with a CM-like phenotype associated with cerebral anomalies and severe epilepsy. Pathogenic variants in PIK3CA and PIK3R1, as well as GNAQ and GNA11, were absent in affected cutaneous tissue biopsies. Instead, we identified two somatic pathogenic variants in the AKT3 gene. Subsequent analysis of the DNA obtained from surgically resected brain tissue of one of the two patients confirmed the presence of the AKT3 variant. Focal cortical dysplasia was also detected in this patient. Genetic analysis thus facilitated workup to reach a precise diagnosis for these patients, associating the vascular anomaly with the neurological symptoms. This study underscores the importance of searching for additional signs and symptoms to guide the diagnostic workup, especially in cases with atypical vascular malformations. In addition, it strongly emphasizes the significance of genotype-phenotype correlation studies in guiding clinicians' informed decision-making regarding patient care., (© 2024 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals LLC.)

Biallelic variants in DI3SL2 cause Perlman Syndrome, associated increased risk for Wilms tumor. Cutis Marmorata Telangiectatica Congenita (CMTC) is a rare congenital disorder characterized by cutaneous vascular anomalies. We report a 2-year-old boy with both Wilms tumor and CMTC. Genetic testing, prompted by his complex presentation, revealed 1 somatic mutation and 1 familial germline mutation in the DIS3L2 gene, suggesting a 2-hit causation of Wilms tumor. Separately, a single GNA11 somatic mutation was identified to explain the CMTC. We suggest that genetic testing for germline mutations associated with Wilms tumor susceptibility be considered even in cases without known family history., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Pathogenic variants in SOX18 are associated with hypotrichosis-lymphedema-telangiectasia-renal defects syndrome (HLTRS) and hypotrichosis-lymphedema-telangiectasia syndrome (HLTS). Eleven patients with SOX18 related HLTRS/HLTS have been previously described. Cardinal features include varying degrees of hypotrichosis, lymphedema and telangiectasias. We report a 15-year-old female patient with a likely de novo SOX18 pathogenic variant identified on duo exome sequencing. In addition to the classic features, the currently reported patient presented with novel clinical features including musculoskeletal abnormalities and strikingly poor wound healing. Chronic skin ulcers have been a major cause of morbidity for the patient and have led to significant functional limitation. Further, our experience with wound management has been detailed. We hope to improve understanding of the clinical spectrum of this ultra-rare disorder by reviewing the phenotypic features in all reported patients including our patient., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Cutis marmorata telangiectatica congenita (CMTC) is characterized by coarse-meshed capillary malformations arranged in asymmetrically distributed patches. The disorder may be associated with hyper- or hypoplastic limbs, syndactyly, cleft palate, and glaucoma. Because the disease usually occurs sporadically, the concept of a lethal mutation surviving by mosaicism was proposed about 30 years ago. Here we describe three children with CMTC due to a postzygotic GNA11 mutation c547C > T (p.Arg183Cys), documented in saliva (patient 1) or lesional cutaneous tissue (patients 2 and 3). All three individuals had widespread and asymmetric CMTC which was present from birth and became fainter during the first years of life. Variably associated anomalies included glaucoma, choroidal capillary malformation, and body asymmetry. In previous case reports, postzygotic GNA11 mutations were documented in two cases of phacomatosis cesiomarmorata, being characterized by CMTC coexisting with segmental dermal melanocytosis. Moreover, postzygotic GNA11 mutations were noted in two CMTC patients described under the incorrect diagnosis of "nevus vascularis mixtus". Hence, the present cases convincingly support the concept that CMTC can be caused by mosaic GNA11 mutations and thus belongs to the GNA11-Related Capillary Nevus (GNARCAN) spectrum. In two other bona fide cases of CMTC, however, we were unable to find a mutation in GNA11, which may be explained either by our inability to detect a very low percentage of mutant cells or by genetic heterogeneity of the phenotype., (Copyright © 2022. Published by Elsevier Masson SAS.)

Mixed vascular naevus (MVN) is characterized by the co-occurrence of telangiectatic capillary malformation and naevus anaemicus, which can appear as a pure cutaneous phenotype or be combined with systemic manifestations such as brain malformations, neurological abnormalities and musculoskeletal disorders. Recently, GNA11 and GNAQ somatic mutations have been reported in some patients with isolated and syndromic MVN. We report three children with MVN syndrome with generalized cutaneous manifestations and a number of systemic associations not reported to date, including ophthalmological anomalies, musculoskeletal abnormalities such as Sprengel deformity and posterior vertebral fusion anomalies, and septal heart defects. We also confirm a somatic mutation of GNA11 in both telangiectatic naevus and naevus anaemicus in two of our patients and discuss a possible common pathogenic mechanism underlying the different manifestations of the syndrome. Currently, there are no guidelines for the evaluation of patients with MVN syndrome, but according to the different known aspects of the disease, a complete clinical examination should be made, and complementary laboratory and imaging tests should be considered., (© 2021 British Association of Dermatologists.)

Few genetically dominant mutations involved in human disease have been fully explained at the molecular level. In cases where the mutant gene encodes a transcription factor, the dominant-negative mode of action of the mutant protein is particularly poorly understood. Here, we studied the genome-wide mechanism underlying a dominant-negative form of the SOX18 transcription factor (SOX18RaOp) responsible for both the classical mouse mutant Ragged Opossum and the human genetic disorder Hypotrichosis-lymphedema-telangiectasia-renal defect syndrome. Combining three single-molecule imaging assays in living cells together with genomics and proteomics analysis, we found that SOX18RaOp disrupts the system through an accumulation of molecular interferences which impair several functional properties of the wild-type SOX18 protein, including its target gene selection process. The dominant-negative effect is further amplified by poisoning the interactome of its wild-type counterpart, which perturbs regulatory nodes such as SOX7 and MEF2C. Our findings explain in unprecedented detail the multi-layered process that underpins the molecular aetiology of dominant-negative transcription factor function., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Background: We describe two unrelated patients who display similar clinical features including telangiectasia, ectodermal dysplasia, brachydactyly and congenital heart disease., Methods: We performed trio whole exome sequencing and functional analysis using in vitro kinase assays with recombinant proteins., Results: We identified two different de novo mutations in protein kinase D1 ( PRKD1, NM_002742.2): c.1774G>C, p.(Gly592Arg) and c.1808G>A, p.(Arg603His), one in each patient. PRKD1 ( PKD1 , HGNC:9407) encodes a kinase that is a member of the protein kinase D (PKD) family of serine/threonine protein kinases involved in diverse cellular processes such as cell differentiation and proliferation and cell migration as well as vesicle transport and angiogenesis. Functional analysis using in vitro kinase assays with recombinant proteins showed that the mutation c.1808G>A, p.(Arg603His) represents a gain-of-function mutation encoding an enzyme with a constitutive, lipid-independent catalytic activity. The mutation c.1774G>C, p.(Gly592Arg) in contrast shows a defect in substrate phosphorylation representing a loss-of-function mutation., Conclusion: The present cases represent a syndrome, which associates symptoms from several different organ systems: skin, teeth, bones and heart, caused by heterozygous de novo mutations in PRKD1 and expands the clinical spectrum of PRKD1 mutations, which have hitherto been linked to syndromic congenital heart disease and limb abnormalities., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Mandibular hypoplasia, deafness, progeroid feature, and lipodystrophy syndrome (MDPL, MIM# 615381) is an extremely rare and recently recognized early adult onset of progeroid syndrome, with features of generalized lipodystrophy, dysmorphic features, telangiectasia, early onset hearing loss, insulin resistance, and dyslipidemia. Here, we present a 31-year-old Chinese woman with MDPL, harboring the recurrent pathogenic variant p.(Ser605del) in POLD1, illustrating the evolving manifestations of this premature aging disorder from infancy to adulthood., (© 2020 Wiley Periodicals LLC.)

Background: The severity of facial telangiectasia or red veins is associated with many lifestyle factors. However, the genetic predisposition remains unclear., Objectives: We performed a genome-wide association study (GWAS) on facial telangiectasia in the Rotterdam Study (RS) and tested for replication in two independent cohorts. Additionally, a candidate gene approach with known pigmentation genes was performed., Methods: Facial telangiectasia were extracted from standardized facial photographs (collected from 2010-2013) of 2842 northwestern European participants (median age 66.9, 56.8% female) from the RS. Our GWAS top hits (P-value <10 -6 ) were tested for replication in 460 elderly women of the SALIA cohort and in 576 additional men and women of the RS. Associations of top single nucleotide polymorphisms (SNPs) with expression quantitative trait loci (eQTL) in various tissues were reviewed (GTEx database) alongside phenotype associations in the UK biobank database. SNP-based associations between known pigmentation genes and facial telangiectasia were tested. Conditional analysis on skin colour was additionally performed., Results: Our most significant GWAS signal was rs4417318 (P-value 5.38*10 -7 ), an intergenic SNP on chromosome 12 mapping to the SLC16A7 gene. Other suggestive SNPs tagged genes ZNF211, ZSCAN4, ICOS and KCNN3; SNP eQTLs and phenotype associations tagged links to the vascular system. However, the top signals did not pass significance in the two replication cohorts. The pigmentation genes KIAA0930, SLCA45A2 and MC1R, were significantly associated with telangiectasia in a candidate gene approach but not independently of skin colour., Conclusion: In this GWAS on telangiectasia in a northwestern European population, no genome-wide significant SNPs were found, although suggestive signals indicate genes involved in the vascular system might be involved in telangiectasia. Significantly associated pigmentation genes underline the link between skin colour and telangiectasia., (© 2020 European Academy of Dermatology and Venereology.)

Competing Interests: Competing interests: None declared.

Vascular complications such as bleeding due to gastrointestinal telangiectatic anomalies, pulmonary arteriovenous malformations, hepatopulmonary syndrome, and retinal vessel abnormalities are being reported in patients with telomere biology disorders (TBDs) more frequently than previously described. The international clinical care consortium of telomere-associated ailments and family support group Dyskeratosis Congenita Outreach, Inc. held a workshop on vascular abnormalities in the TBDs at the National Cancer Institute in October 2017. Clinicians and basic scientists reviewed current data on vascular complications, hypotheses for the underlying biology and developed new collaborations to address the etiology and clinical management of vascular complications in TBDs.

Hypotrichosis-lymphedema-telangiectasia syndrome (HLTS) is a rare disorder caused by autosomal recessive and autosomal dominant mutations in SOX18. This gene encodes a transcription factor involved in the regulation and development of the human vasculature, lymphatic, and integumentary systems. Individuals with HLTS develop varying degrees of hypotrichosis, lymphedema, and telangiectasias. Other complications, such as renal failure and aortic dilation, have also been observed. Here, we report a neonate with a novel mutation in SOX18 (c.541C>T; p.Gln181stop) presenting with cardinal features of HLTS in addition to unique findings of severe chylothorax and relentless pulmonary hypertension that culminated in death. The purpose of this report is to summarize what is known about this evolving genetic syndrome and to speculate as to how mutations in SOX18 might produce the phenotype., (© 2018 Wiley Periodicals, Inc.)

Background: Mitotic fission is increased in pulmonary arterial hypertension (PAH), a hyperproliferative, apoptosis-resistant disease. The fission mediator dynamin-related protein 1 (Drp1) must complex with adaptor proteins to cause fission. Drp1-induced fission has been therapeutically targeted in experimental PAH. Here, we examine the role of 2 recently discovered, poorly understood Drp1 adapter proteins, mitochondrial dynamics protein of 49 and 51 kDa (MiD49 and MiD51), in normal vascular cells and explore their dysregulation in PAH., Methods: Immunoblots of pulmonary artery smooth muscle cells (control, n=6; PAH, n=8) and immunohistochemistry of lung sections (control, n=6; PAH, n=6) were used to assess the expression of MiD49 and MiD51. The effects of manipulating MiDs on cell proliferation, cell cycle, and apoptosis were assessed in human and rodent PAH pulmonary artery smooth muscle cells with flow cytometry. Mitochondrial fission was studied by confocal imaging. A microRNA (miR) involved in the regulation of MiD expression was identified using microarray techniques and in silico analyses. The expression of circulatory miR was assessed with quantitative reverse transcription-polymerase chain reaction in healthy volunteers (HVs) versus patients with PAH from Sheffield, UK (plasma: HV, n=29, PAH, n=27; whole blood: HV, n=11, PAH, n=14) and then confirmed in a cohort from Beijing, China (plasma: HV, n=19, PAH, n=36; whole blood: HV, n=20, PAH, n=39). This work was replicated in monocrotaline and Sugen 5416-hypoxia, preclinical PAH models. Small interfering RNAs targeting MiDs or an miR mimic were nebulized to rats with monocrotaline-induced PAH (n=4-10)., Results: MiD expression is increased in PAH pulmonary artery smooth muscle cells, which accelerates Drp1-mediated mitotic fission, increases cell proliferation, and decreases apoptosis. Silencing MiDs (but not other Drp1 binding partners, fission 1 or mitochondrial fission factor) promotes mitochondrial fusion and causes G1-phase cell cycle arrest through extracellular signal-regulated kinases 1/2- and cyclin-dependent kinase 4-dependent mechanisms. Augmenting MiDs in normal cells causes fission and recapitulates the PAH phenotype. MiD upregulation results from decreased miR-34a-3p expression. Circulatory miR-34a-3p expression is decreased in both patients with PAH and preclinical models of PAH. Silencing MiDs or augmenting miR-34a-3p regresses experimental PAH., Conclusions: In health, MiDs regulate Drp1-mediated fission, whereas in disease, epigenetic upregulation of MiDs increases mitotic fission, which drives pathological proliferation and apoptosis resistance. The miR-34a-3p-MiD pathway offers new therapeutic targets for PAH., (© 2018 American Heart Association, Inc.)

A patient with extensive multisystem overgrowth caused by a somatic gain of function PIK3CA-mutation is described. This case is an example of the clinical diversity of the PIK3CA-Related Overgrowth Spectrum (PROS) as the patient had overlapping features of Congenital Lipomatous Overgrowth Vascular malformations Epidermal nevi and Skeletal abnormalities (CLOVES) syndrome and Megalencephaly-Capillary malformation Polymicrogyria (MCAP) syndrome and underlines the utility of this umbrella term., (© 2018 Wiley Periodicals, Inc.)

The transcription factor SOX18 has been shown to play a role in the development of hair, blood and lymphatic vessels. Mutations in SOX18 result in hereditary lymphedema, with the unique clinical association of hypotrichosis and telangiectasia (HLTS). Some patients present with additional disease features which may be explained by the location of SOX18 mutation. We report a patient with hypotrichosis-lymphedema-telangiectasia syndrome (HLTS) confirmed by detection of a novel mutation in the SOX18 gene. Few cases of HTLS have been reported in the literature. We reviewed all cases reported to date to delineate the clinical manifestations that allow us to prompt diagnosis of this syndrome for appropriate management and genetic counseling., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Chromosome 10q23 contains several genes, includingPTENandBMPR1A, the mutations or microdeletion of which are associated with aggressive polyposis and malignancies in children. Deletions in this chromosomal region have also been associated with heart anomalies, developmental delay and macrocephaly. Most of the cases reported involve thePTENandBMPR1Agenes, usually associated with complex and severe anomalies. We report a case of a boy with a de novo interstitial microdeletion in 10q23.1-q23.2 spanning 6.7 Mb with boundaries from 82 087 077 to 88 847 906, not includingPTENandBMPR1A Clinical features consisted of mildly dysmorphic facies, frontal telangiectasias, poor scholastic performance and hyperactivity. Furthermore, the boy presented toe anomalies, which appeared to be novel features associated with 10q23 deletion. Further observations of 10q23.1-q23.2 deletions are necessary to confirm the clinical features observed in the proband, and to show that deletion or mutations not involvingPTENandBMPR1Amay not be associated with severe neurological impairment and malformation anomalies., (2016 BMJ Publishing Group Ltd.)

The megalencephaly capillary malformation syndrome (MCAP, OMIM 602501) is known to be associated with mosaic mutations in PIK3CA occurring during embryogenesis. Standard sequencing technologies are relatively poor at indentifying sequence changes that only affect a small percentage of cells, and the mutations are frequently not identified in lymphocyte DNA, with biopsies of the affected tissues often being required to detect mosaic mutations. Such invasive procedures are not always acceptable to parents. We describe the case of a patient in whom we were able to confirm a causative PIK3CA mutation, first found thorugh next-generation sequencing, in several tissue types including a secondary tooth. As part of this work, we were also able to begin validating dental tissue for potential use in genetic testing, as we achieved excellent DNA yields with minimal effort, even from deciduous teeth shed some years earlier.

Background: We report a 13-year-old female patient followed since birth for multiple rare congenital defects, including hypotrichosis, telangiectasia, and severe dilatation of the ascending aorta., Methods: Comprehensive phenotype assessment throughout childhood included repeated echocardiographic measurements, evaluation of renal function, and immunohistochemical analysis of skin biopsy samples. Whole-exome sequencing was performed for the patient and both unaffected parents., Results: We identified a novel de novo mutation in the transcription factor SOX18 (c.481C>T:p.Gln161*) in the patient, which was absent in all unaffected family members. Echocardiography revealed early onset and progressive dilatation of the ascending aorta. Skin biopsy results confirmed the defects of the blood vasculature in the presence of intact lymphatic vessels. Assessment of renal function did not show any signs of renal problems or renal failure in the patient., Conclusions: The genetic finding of a pathogenic SOX18 mutation enabled the diagnosis of the rare hypotrichosis-lymphedema-telangiectasia syndrome in our patient. The identification of a novel stop gain mutation in the SOX18 gene in association with dilatation of the aorta highlights the importance of this gene during the development of the circulatory system. Our study highlights the importance of whole-exome sequencing in the rapid identification of genes and gene mutations involved in rare conditions and thus expanding the knowledge and spectrum of clinical manifestations associated with them., (Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Importance: Facial erythema and telangiectasia are commonly associated with the erythematotelangiectatic subtype of rosacea (ETR). It is important for clinicians to recognize that these findings can also be associated with a subtype of photoaging, which we term telangiectatic photoaging (TP)., Objective: To demonstrate that ETR and TP are distinct dermatologic disorders., Design: A case-control observational study comparing clinical, histologic, and gene expression features of 26 participants with ETR, 20 with TP, and 11 age- and sex-matched controls in the Program for Clinical Research in Dermatology at University of Michigan., Main Outcomes and Measures: Findings of clinical history and examination, light and electron microscopy, immunohistochemical analyses, and real-time quantitative reverse-transcriptase polymerase chain reaction gene expression., Results: Transient erythema was greater in the ETR group (38% graded moderate to severe) than in the TP (0%; P < .001) and control groups (0%; P = .002). Nontransient erythema was also greater in the ETR group (50% graded moderate to severe) than in the TP (25%; P = .03) and control groups (0%; P < .001). Participants with ETR tended to have erythema and telangiectasia primarily on the central face (79%), whereas those with TP tended to have more lateral involvement (57%; P < .001). Those with ETR had significantly less clinical evidence of photodamage (0% graded 6-8 on a photonumeric scale) than those with TP (40% graded 6-8; P = .01). Histologically, there was less evidence of photodamage in ETR than in TP, which had wispy collagen and solar elastosis surrounding blood vessels. Immunohistologic analysis demonstrated greater geometric mean immunostained area by mast cell tryptase staining in ETR samples (0.018%) than in TP (0.004%; P = .01) or control samples (0.001%; P < .001) but no increase in mast cell number, indicative of greater mast cell degranulation. Gene expression of matrix metalloproteinase-3 was 4-fold greater in ETR samples than in TP samples (P = .004) and 5-fold higher than in control samples (P = .004). Gene expression of the neuropeptides calcitonin gene-related peptide (CGRP-α) and substance P was significantly increased in ETR compared with TP (9-fold [P < .001] and 5-fold [P = .002], respectively) and control samples (10-fold [P < .001] and 28-fold [P < .001], respectively)., Conclusions and Relevance: Telangiectatic photoaging is characterized by less transient and nontransient erythema, a more lateral distribution of erythema and telangiectasia, less neurogenic mast cell activation, and less MMP-mediated matrix remodeling than ETR. These data demonstrate that TP is a distinct clinical entity from ETR that can be distinguished on the basis of clinical, histologic, and gene expression findings.

Cutis Marmorata Telangiectatica Congenita (CMTC) is a congenital localized or generalized vascular anomaly, usually sporadic in occurrence. It can be associated with other cutaneous or systemic manifestations. About 300 cases have been reported. The molecular etiology remains largely unknown. The main purpose of this study is to delineate the molecular basis for a syndromic CMTC phenotype in a consanguineous Saudi family. Clinical phenotyping including detailed neurological imaging, followed by autozygosity mapping and trio whole exome sequencing (WES) are also studied. We have identified a homozygous truncating mutation in ARL6IP6 as the likely cause of a syndromic form of CMTC associated with major dysmorphism, developmental delay, transient ischemic attacks and cerebral vascular malformations. This gene was previously implicated by genome wide association study (GWAS) as a susceptibility locus to ischemic stroke in young adults. We identify ARL6IP6 as a novel candidate gene for a syndromic form of CMTC. This suggests that ischemic stroke or transient ischemic attacks (TIA) may represent, at least in some cases, the mild end of a phenotypic spectrum that has at its severe end autosomal recessive CMTC. This finding contributes to a growing appreciation of the continuum of Mendelian and common complex diseases.

We have identified and characterized a spontaneous Brown Norway from Janvier rat strain (BN-J) presenting a progressive retinal degeneration associated with early retinal telangiectasia, neuronal alterations, and loss of retinal Müller glial cells resembling human macular telangiectasia type 2 (MacTel 2), which is a retinal disease of unknown cause. Genetic analyses showed that the BN-J phenotype results from an autosomal recessive indel novel mutation in the Crb1 gene, causing dislocalization of the protein from the retinal Müller glia (RMG)/photoreceptor cell junction. The transcriptomic analyses of primary RMG cultures allowed identification of the dysregulated pathways in BN-J rats compared with wild-type BN rats. Among those pathways, TGF-β and Kit Receptor Signaling, MAPK Cascade, Growth Factors and Inflammatory Pathways, G-Protein Signaling Pathways, Regulation of Actin Cytoskeleton, and Cardiovascular Signaling were found. Potential molecular targets linking RMG/photoreceptor interaction with the development of retinal telangiectasia are identified. This model can help us to better understand the physiopathologic mechanisms of MacTel 2 and other retinal diseases associated with telangiectasia., (Copyright © 2015 the authors 0270-6474/15/356093-14$15.00/0.)

SOX18 mutations in humans are associated with both recessive and dominant hypotrichosis-lymphedema-telangiectasia syndrome (HLTS). We report two families with affected children carrying a SOX18 mutation: a living patient and his stillborn brother from Canada and a Belgian patient. The two living patients were diagnosed with HLTS and DNA analysis for the SOX18 gene showed that both had the identical heterozygous C > A transversion, resulting in a pre-mature truncation of the protein, lacking the transactivation domain. Both living patients developed renal failure with severe hypertension in childhood for which both underwent renal transplantation. To our best knowledge this is the first report of renal failure associated with heterozygous mutations in the SOX18 gene. We conclude that this specific mutation results in a new, autosomal dominant condition and propose the acronym HLT-renal defect syndrome for HLTRS., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

We report a new case of Warsaw Breakage syndrome (WABS) with 2 confirmed mutations in DDX11. Like the previous reported cases [Capo-Chichi et al., 2012; Van der Lelij et al., 2010], there was evidence of pre- and postnatal growth retardation, severe microcephaly, intellectual disability and facial dysmorphism. The patient had sensorineural hearing loss with evidence of bilateral hypoplastic cochleas on imaging, another feature which has been reported in the previous cases of WABS. In our case the patient exhibited a chronic rash of livedo reticularis with telangiectasia on her legs. Abnormally pigmented lesions and cutis mamorata were reported in the original WABS case., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Megalencephaly-capillary malformation (MCAP) syndrome is an overgrowth syndrome that is diagnosed by clinical criteria. Recently, somatic and germline variants in genes that are involved in the PI3K-AKT pathway (AKT3, PIK3R2 and PIK3CA) have been described to be associated with MCAP and/or other related megalencephaly syndromes. We performed trio-exome sequencing in a 6-year-old boy and his healthy parents. Clinical features were macrocephaly, cutis marmorata, angiomata, asymmetric overgrowth, developmental delay, discrete midline facial nevus flammeus, toe syndactyly and postaxial polydactyly--thus, clearly an MCAP phenotype. Exome sequencing revealed a pathogenic de novo germline variant in the PTPN11 gene (c.1529A>G; p.(Gln510Arg)), which has so far been associated with Noonan, as well as LEOPARD syndrome. Whole-exome sequencing (>100 × coverage) did not reveal any alteration in the known megalencephaly genes. However, ultra-deep sequencing results from saliva (>1000 × coverage) revealed a 22% mosaic variant in PIK3CA (c.2740G>A; p.(Gly914Arg)). To our knowledge, this report is the first description of a PTPN11 germline variant in an MCAP patient. Data from experimental studies show a complex interaction of SHP2 (gene product of PTPN11) and the PI3K-AKT pathway. We hypothesize that certain PTPN11 germline variants might drive toward additional second-hit alterations.

We tested apoptosis levels in in vitro irradiated T-lymphocytes from breast cancer (BC) patients with radiotherapy-induced late effects. Previous results reported in the literature were revised. We also examined the effect of TP53 Arg72Pro polymorphism on irradiation-induced apoptosis (IA). Twenty BC patients, ten with fibrosis and/or telangiectasias and ten matched controls with no late reactions, were selected from those receiving radiotherapy between 1993 and 2007. All patients were followed-up at least 6 years after radiotherapy. Using the combination of both CD3 and CD8 antibodies the in vitro IA was measured in CD3, CD8 and CD4 T-lymphocytes, and CD8 natural killer lymphocytes (CD8 NK) by flow cytometry. The TP53 Arg72Pro genotype was determined by sequencing. Patients with late radiotherapy toxicity showed less IA for all T-lymphocytes except for the CD8 NK. CD8 NK showed the highest spontaneous apoptosis and the lowest IA. IA in patients with toxicity appears to be lower than the control patients only in TP53 Arg/Arg patients (P = 0.077). This difference was not present in patients carrying at least one Pro allele (P = 0.8266). Our data indicate that late side effects induced by radiotherapy of BC are associated to low levels of IA. CD8 NK cells have a different response to in vitro irradiation compared to CD8 T-lymphocytes. It would be advisable to distinguish the CD8 NK lymphocytes from the pool of CD8+ lymphocytes in IA assays using CD8+ cells. Our data suggest that the 72Pro TP53 allele may influence the IA of patients with radiotherapy toxicity.

Numerous human disorders, including Cockayne syndrome, UV-sensitive syndrome, xeroderma pigmentosum, and trichothiodystrophy, result from the mutation of genes encoding molecules important for nucleotide excision repair. Here, we describe a syndrome in which the cardinal clinical features include short stature, hearing loss, premature aging, telangiectasia, neurodegeneration, and photosensitivity, resulting from a homozygous missense (p.Ser228Ile) sequence alteration of the proliferating cell nuclear antigen (PCNA). PCNA is a highly conserved sliding clamp protein essential for DNA replication and repair. Due to this fundamental role, mutations in PCNA that profoundly impair protein function would be incompatible with life. Interestingly, while the p.Ser228Ile alteration appeared to have no effect on protein levels or DNA replication, patient cells exhibited marked abnormalities in response to UV irradiation, displaying substantial reductions in both UV survival and RNA synthesis recovery. The p.Ser228Ile change also profoundly altered PCNA's interaction with Flap endonuclease 1 and DNA Ligase 1, DNA metabolism enzymes. Together, our findings detail a mutation of PCNA in humans associated with a neurodegenerative phenotype, displaying clinical and molecular features common to other DNA repair disorders, which we showed to be attributable to a hypomorphic amino acid alteration.

Mutations in SOX18, VEGFC and Vascular Endothelial Growth Factor 3 underlie the hereditary lymphatic disorders hypotrichosis-lymphedema-telangiectasia (HLT), Milroy-like lymphedema and Milroy disease, respectively. Genes responsible for hereditary lymphedema are key regulators of lymphatic vascular development in the embryo. To identify novel modulators of lymphangiogenesis, we used a mouse model of HLT (Ragged Opossum) and performed gene expression profiling of aberrant dermal lymphatic vessels. Expression studies and functional analysis in zebrafish and mice revealed one candidate, ArfGAP with RhoGAP domain, Ankyrin repeat and PH domain 3 (ARAP3), which is down-regulated in HLT mouse lymphatic vessels and necessary for lymphatic vascular development in mice and zebrafish. We position this known regulator of cell behaviour during migration as a mediator of the cellular response to Vegfc signalling in lymphatic endothelial cells in vitro and in vivo. Our data refine common mechanisms that are likely to contribute during both development and the pathogenesis of lymphatic vascular disorders.

We describe a case of recurrent primary hyperparathyroidism, manifested as 3 metachronous parathyroid adenomata, in a 50 year-old woman who also had Hashimoto hypothyroidism, gastric gastrointestinal stromal tumour (GIST), cysts in liver and kidneys, 5 intestinal polyps (one of these a villous adenoma), diverticulitis and telangiectasia of lips. She did not have medullary thyroid carcinoma (MTC). Genetic analysis of the CDC73 gene [for Hyperparathyroidism-jaw tumor (HPT-JT)], MEN1 for Multiple Endocrine Neoplasia Type1, CDKN1B for MEN4, SDHB and SDHD for Paraganglioma/Pheochromocytoma susceptibility, VHL for von Hippel-Lindau Syndrome, BMPR1A and SMAD4 for Juvenile Polyposis Syndrome (JPS) (sequencing and MLPA), karyotype and array CGH (44 K) were all normal. She was found to be homozygous for a synonomous germline variant in exon 14 (p. Ser836Ser) of the RET oncogene. This RET variant is of unclear clinical significance, and has been previously reported both in normal individuals and in individuals with MTC. It is unlikely that homozygosity for the RET variant has been casual in the multiple pathologies that our patient has developed.

Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs)., Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients., Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P≤.005)., Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Macular telangiectasia type 2 is a bilateral disease of unknown cause with characteristic alterations of the macular capillary network and neurosensory atrophy. Its prevalence may be underestimated and has recently been shown to be as high as 0.1% in persons 40 years and older. Biomicroscopy may show reduced retinal transparency, crystalline deposits, mildly ectatic capillaries, blunted venules, retinal pigment plaques, foveal atrophy, and neovascular complexes. Fluorescein angiography shows telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. High-resolution optical coherence tomography (OCT) may reveal disruption of the photoreceptor inner segment-outer segment border, hyporeflective cavities at the level of the inner or outer retina, and atrophy of the retina in later stages. Macular telangiectasia type 2 shows a unique depletion of the macular pigment in the central retina and recent therapeutic trials showed that such depleted areas cannot re-accumulate lutein and zeaxanthin after oral supplementation. There have been various therapeutic approaches with limited or no efficacy. Recent clinical trials with compounds that block vascular endothelial growth factor (VEGF) have established the role of VEGF in the pathophysiology of the disease, but have not shown significant efficacy, at least for the non-neovascular disease stages. Recent progress in structure-function correlation may help to develop surrogate outcome measures for future clinical trials. In this review article, we summarize the current knowledge on macular telangiectasia type 2, including the epidemiology, the genetics, the clinical findings, the staging and the differential diagnosis of the disease. Findings using retinal imaging are discussed, including fluorescein angiography, OCT, adaptive optics imaging, confocal scanning laser ophthalmoscopy, and fundus autofluorescence, as are the findings using visual function testing including visual acuity and fundus-controlled microperimetry. We provide an overview of the therapeutic approaches for both non-neovascular and neovascular disease stages and provide a perspective of future directions including animal models and potential therapeutic approaches., (2012 Elsevier Ltd. All rights reserved)

Aims: Coronary telangiectasia (CT) is a rare congenital anomaly causing ventricular shunt and myocardial ischaemia. Its prevalence, genetic background, and impact in human hypertrophic cardiomyopathy (HCM) are unknown and were therefore investigated in this study., Methods and Results: Among 445 patients with HCM, 195 had a coronary angiography and 124 a left ventricular endomyocardial biopsy. CT draining into the ventricular cavities was observed in 5 of 195 HCM patients (2.5%), whereas it was detected in 0.1% of 1000 consecutive subjects without congenital anomalies undergoing coronary angiography. Patients with CT-HCM underwent a total body computed tomography scan to investigate the presence of systemic vascular malformations. HCM-related MYH7, MYBPC3, TNNT2, and TPM1 genes and hereditary haemorragic telangiectasia-related endoglin and activin receptor-like kinase 1 genes were analysed. Histology, clinical profile, and outcome of CT-HCM patients were correlated with those of 22 control HCM patients. No mucocutaneous or systemic vascular malformations were detected. Gene analysis showed a MYH7 mutation in two patients, with an associated endoglin point mutation. Histology showed in the CT-HCM cohort a more pronounced myocardial fibrosis (29.8 ± 3.8%) compared with HCM controls (13 ± 2.6%), and disorganized cardiomyocytes separated by thin-walled large vessels adherent to the endocardium. Clinically, the CT-HCM cohort had a higher arrhythmic profile at diagnosis and increased incidence of implantable cardioverter defibrillator (ICD) implantations and arrhythmic deaths during a long-term follow-up., Conclusion: CT is detectable in 2.5% of HCM patients vs. 0.1% of the general population; it may derive from a co-existing endoglin gene mutation and cause a prominent, potentially arrhythmogenic myocardial fibrosis.

Purpose of Review: To summarize clinically relevant findings in the genetic cause and gene expression of vascular anomalies., Recent Findings: Infantile hemangioma demonstrates familial clustering and is associated with atopic disease. Variable gene expression is seen in infantile hemangioma during proliferation and involution. Capillary malformation may be sporadic or inherited in an autosomal dominant pattern. Capillary malformation-arteriovenous malformation is caused by mutation in RASA1. Some inherited forms of lymphedema are due to mutation in VEGFR3. Venous malformation may be sporadic, paradominant, or autosomal dominant inheritance. Autosomal dominantly inherited forms of venous malformation are due to mutations in TIE2/TEK. Additionally, TIE2 somatic mutations have been identified in about half of sporadic venous malformations., Summary: Multiple genes have been identified causing inherited forms of vascular anomalies including capillary malformations, venous malformations and lymphedema. Variable gene expression of infantile hemangioma during proliferation and involution may offer new therapeutic targets for treatment.

Purpose: In patients receiving radiotherapy for breast cancer where the heart is within the radiation field, cutaneous telangiectasiae could be a marker of potential radiation-induced heart disease. We hypothesized that single nucleotide polymorphisms (SNPs) in genes known to cause heritable telangiectasia-associated disorders could predispose to such late, normal tissue vascular damage., Methods and Materials: The relationship between cutaneous telangiectasia as a late normal tissue radiation injury phenotype in 633 breast cancer patients treated with radiotherapy was examined. Patients were clinically assessed for the presence of cutaneous telangiectasia and genotyped at nine SNPs in three candidate genes. Candidate SNPs were within the endoglin (ENG) and activin A receptor, type II-like 1 (ACVRL1) genes, mutations in which cause hereditary hemorrhagic telangiectasia and the ataxia-telangiectasia mutated (ATM) gene associated with ataxia-telangiectasia., Results: A total of 121 (19.1%) patients exhibited a degree of cutaneous telangiectasiae on clinical examination. Regression was used to examine the associations between the presence of telangiectasiae in patients who underwent breast-conserving surgery, controlling for the effects of boost and known brassiere size (n=388), and individual geno- or haplotypes. Inheritance of ACVRL1 SNPs marginally contributed to the risk of cutaneous telangiectasiae. Haplotypic analysis revealed a stronger association between inheritance of a ATM haplotype and the presence of cutaneous telangiectasiae, fibrosis and overall toxicity. No significant association was observed between telangiectasiae and the coinheritance of the candidate ENG SNPs., Conclusions: Genetic variation in the ATM gene influences reaction to radiotherapy through both vascular damage and increased fibrosis. The predisposing variation in the ATM gene will need to be better defined to optimize it as a predictive marker for assessing radiotherapy late effects., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Mammosphere culture of cancer cell lines is an important approach used for enrichment of stem-like cancer cells (SLCs), but over-subcultured cell lines have been experimentally shown to change properties over time. It remains unclear if mammosphere cells (MSs) derived from high-passage cancer cell lines retain the tumorigenicity and radioresistance seen in MSs from primary or low-passage cell lines. In this study, we report that mammospheres derived from MCF-7 sublines after different passage numbers were consistently enriched for CD44+/CD24(-/low) cells but were not consistently enriched for tumorigenic and radioresistant cells. The tumorigenicity and radioresistance of MSs were associated with their sphere-forming ability, proliferation ability in vitro, and intracellular reactive oxygen species (ROS) levels. The radioresistant MSs showed significant cell cycle arrest in G2/M phase after X-ray irradiation and expressed higher ataxia telangiectasia mutated (ATM) mRNA levels. These results suggest that MSs from high-passage cancer cell lines were not consistently enriched for stem-like cancer cells with higher tumorigenicity and enhanced radioresistance., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To find the gene(s) responsible for macular telangiectasia type 2 (MacTel) by a candidate-gene screening approach., Methods: Candidate genes were selected based on the following criteria: those known to cause or be associated with diseases with phenotypes similar to MacTel, genes with known function in the retinal vasculature or macular pigment transport, genes that emerged from expression microarray data from mouse models designed to mimic MacTel phenotype characteristics, and genes expressed in the retina that are also related to diabetes or hypertension, which have increased prevalence in MacTel patients. Probands from eight families with at least two affected individuals were screened by direct sequencing of 27 candidate genes. Identified nonsynonymous variants were analyzed to determine whether they co-segregate with the disease in families. Allele frequencies were determined by TaqMan analysis of the large MacTel and control cohorts., Results: We identified 23 nonsynonymous variants in 27 candidate genes in at least one proband. Of these, eight were known single nucleotide polymorphisms (SNPs) with allele frequencies of >0.05; these variants were excluded from further analyses. Three previously unidentified missense variants, three missense variants with reported disease association, and five rare variants were analyzed for segregation and/or allele frequencies. No variant fulfilled the criteria of being causal for MacTel. A missense mutation, p.Pro33Ser in frizzled homolog (Drosophila) 4 (FZD4), previously suggested as a disease-causing variant in familial exudative vitreoretinopathy, was determined to be a rare benign polymorphism., Conclusions: We have ruled out the exons and flanking intronic regions in 27 candidate genes as harboring causal mutations for MacTel.

Macrocephaly-capillary malformation (M-CM) is a genetic syndrome of unknown etiology characterized by an enlarged head circumference and patchy, reticular capillary malformation. We describe the clinical features of 13 cases, report on the genome-wide Copy Number Variation characterization of these patients, analyze the main clinical features of this syndrome and propose a modification of the current diagnostic criteria: the inclusion of both overgrowth/asymmetry and neuroimaging alterations as major criteria., (© 2010 Wiley-Liss, Inc.)