First Case of KRT2 Epidermolytic Nevus and Novel Clinical and Genetic Findings in 26 Italian Patients with Keratinopathic Ichthyoses

Keratinopathic ichthyoses (KI) are a clinically heterogeneous group of keratinization disorders due to mutations in KRT1, KTR10, or KRT2 genes encoding keratins of suprabasal epidermis. Characteristic clinical features include superficial blisters and erosions in infancy and progressive development of hyperkeratosis. Histopathology shows epidermolytic hyperkeratosis. We describe the clinical, histopathological, and molecular findings of a series of 26 Italian patients from 19 unrelated families affected with (i) epidermolytic ichthyosis due to KRT1 or KRT10 mutations (7 and 9 cases, respectively); (ii) KTR10-mutated ichthyosis with confetti (2 cases); (iii) KRT2-mutated superficial epidermolytic ichthyosis (5 cases); and (iv) KRT10-mutated epidermolytic nevus (2 cases). Of note, molecular genetic testing in a third case of extensive epidermolytic nevus revealed a somatic missense mutation (p.Asn186Asp) in the KRT2 gene, detected in DNA from lesional skin at an allelic frequency of 25% and, at very low frequency (1.5%), also in blood. Finally, we report three novel dominant mutations, including a frameshift mutation altering the C-terminal V2 domain of keratin 1 in three familiar cases presenting a mild phenotype. Overall, our findings expand the phenotypic and molecular spectrum of KI and show for the first time that epidermolytic nevus can be due to somatic KRT2 mutation.

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Ichthyoses—A Clinical and Pathological Spectrum from Heterogeneous Cornification Disorders to Inflammation

Dermatopathology ◽

10.3390/dermatopathology8020017 ◽

2021 ◽

Vol 8 (2) ◽

pp. 107-123

Author(s):

Dieter Metze ◽

Heiko Traupe ◽

Kira Süßmuth

Keyword(s):

Stratum Granulosum ◽

Internal Organs ◽

Histopathologic Diagnosis ◽

Epidermolytic Ichthyosis ◽

Life Threatening ◽

Keratinization Disorders ◽

Gene Defects ◽

Immunohistochemical Methods

Ichthyoses are inborn keratinization disorders affecting the skin only (non-syndromic) or are associated with diseases of internal organs (syndromic). In newborns, they can be life-threatening. The identification of the gene defects resulted in reclassification and a better understanding of the pathophysiology. Histopathologic patterns include orthohyperkeratosis with a reduced or well-developed stratum granulosum, hyperkeratosis with ortho- and parakeratosis with preserved or prominent stratum granulosum, and epidermolytic ichthyosis. Another pattern features “perinuclear vacuoles and binucleated keratinocytes”, which is associated with keratin mutations. Some ichthyoses are histologically defined by psoriasis-like features, and distinct subtypes show follicular hyperkeratosis. In addition to histological and immunohistochemical methods, these patterns allow a better histopathologic diagnosis.

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HGG-26. H3G34V MUTATION AFFECTS GENOMIC H3K36 METHYLATION IN PEDIATRIC GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.310 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii348-iii348

Author(s):

Tina Huang ◽

Andrea Piunti ◽

Elizabeth Bartom ◽

Jin Qi ◽

Rintaro Hashizume ◽

...

Keyword(s):

Western Blot ◽

Allelic Frequency ◽

Glioma Cell Line ◽

Fluorescent Imaging ◽

Wild Type ◽

Gene Expressions ◽

Pediatric Glioma ◽

Genes Encoding ◽

Normal Human

Abstract BACKGROUND Histone H3.3 mutation (H3F3A) occurs in 50% of cortical pediatric high-grade gliomas. This mutation replaces glycine 34 with arginine or valine (G34R/V), impairing SETD2 activity (H3K36-specific trimethyltransferase), resulting in reduced H3K36me on H3G34V nucleosomes relative to wild-type. This contributes to genomic instability and drives distinct gene expressions associated with tumorigenesis. However, it is not known if this differential H3K36me3 enrichment is due to H3G34V mutant protein alone. Therefore, we set to elucidate the effect of H3G34V on genomic H3K36me3 enrichment in vitro. METHODS Doxycycline-inducible short hairpin RNA (shRNA) against H3F3A was delivered via lentivirus to established H3G34V mutant pediatric glioma cell line KNS42, and H3G34V introduced into H3.3 wild type normal human astrocytes (NHA). Transfections were confirmed by western blot, fluorescent imaging, and flow cytometry, with resulting H3.3WT and H3K36me3 expression determined by western blot. H3.3WT, H3K36me3, and H3G34V ChIP-Seq was performed to evaluate genomic enrichment. RESULTS Complete knockdown of H3G34V was achieved with DOX-induced shRNA, with no change in total H3.3, suggesting disproportionate allelic frequency of genes encoding H3.3 (H3F3A and H3F3B). Modest increase in H3K36me3 occurred after H3F3A-knockdown from KNS42, suggesting H3G34V alone impacts observed H3K36me3 levels. Distinct H3K36me3 genomic enrichment was observed with H3G34V knock-in. CONCLUSIONS We demonstrate that DOX-inducible knockdown of H3F3A in an H3G34V mutant pediatric glioma cells and H3G34V mutation transduction in wild-type astrocytes affects H3K36me3 expression. Further evaluation by ChIP-Seq analysis for restoration of wild-type genomic H3K36me3 enrichment patterns with H3G34V knockdown, and mutant H3K36me3 patterns with H3G34V transduction, is currently underway.

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Non-Syndromic Dentinogenesis Imperfecta Caused by Mild Mutations in COL1A2

Journal of Personalized Medicine ◽

10.3390/jpm11060526 ◽

2021 ◽

Vol 11 (6) ◽

pp. 526

Author(s):

Yejin Lee ◽

Youn Jung Kim ◽

Hong-Keun Hyun ◽

Jae-Cheoun Lee ◽

Zang Hee Lee ◽

...

Keyword(s):

Collagen Type ◽

Molecular Genetic ◽

Collagen Type I ◽

Type I ◽

Dentinogenesis Imperfecta ◽

Gene Encoding ◽

Korean Families ◽

Whole Exome ◽

Genes Encoding ◽

Candidate Gene Sequencing

Hereditary dentin defects can be categorized as a syndromic form predominantly related to osteogenesis imperfecta (OI) or isolated forms without other non-oral phenotypes. Mutations in the gene encoding dentin sialophosphoprotein (DSPP) have been identified to cause dentinogenesis imperfecta (DGI) Types II and III and dentin dysplasia (DD) Type II. While DGI Type I is an OI-related syndromic phenotype caused mostly by monoallelic mutations in the genes encoding collagen type I alpha 1 chain (COL1A1) and collagen type I alpha 2 chain (COL1A2). In this study, we recruited families with non-syndromic dentin defects and performed candidate gene sequencing for DSPP exons and exon/intron boundaries. Three unrelated Korean families were further analyzed by whole-exome sequencing due to the lack of the DSPP mutation, and heterozygous COL1A2 mutations were identified: c.3233G>A, p.(Gly1078Asp) in Family 1 and c.1171G>A, p.(Gly391Ser) in Family 2 and 3. Haplotype analysis revealed different disease alleles in Families 2 and 3, suggesting a mutational hotspot. We suggest expanding the molecular genetic etiology to include COL1A2 for isolated dentin defects in addition to DSPP.

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BIOM-47. LONGITUDINAL MONITORING OF PLASMA H3K27M IN DIFFUSE MIDLINE GLIOMA PATIENTS TREATED WITH ONC201

Neuro-Oncology ◽

10.1093/neuonc/noaa215.044 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii11-ii11

Author(s):

Rohinton S Tarapore ◽

Amanda Field ◽

D Ashley Hill ◽

Joshua Allen

Keyword(s):

Radiographic Progression ◽

Low Frequency ◽

Circulating Tumor Dna ◽

Allelic Frequency ◽

Who Grade ◽

Line Radiation ◽

Complication Risk ◽

Droplet Pcr ◽

Tumor Dna ◽

Diffuse Midline Glioma

Abstract Diffuse midline glioma, H3 K27M-mutant (DMG) is a 2016 WHO Grade IV glioma that has no established treatment beyond first-line radiation. ONC201 is an investigational small molecule that has been shown to be clinically active in recurrent DMG clinical trials. While biopsies of DMG are sometimes feasible, many patients defer secondary to complication risk. MR scans have many limitations in monitoring DMG progression, including distinguishing pseudoprogression and pseudoresponse and measuring diffuse lesions that often do not contrast enhance. Digital droplet PCR (ddPCR) is capable of sensitively detecting and quantifying the allelic frequency of circulating-tumor DNA (ctDNA) fragments against a backdrop of non-tumor DNA. Using sequence-specific probes for H3F3A (H3.3 K27M) and HIST1H3B (H3.1 K27M) ddPCR detects very low frequency variants and provides an assessment of mutational burden. A pilot cohort of 5 patients treated with ONC201 who had a range of outcomes were assessed with serial ctDNA analyses. Two patients with immediately progressive disease had a concordant H3 K27M ctDNA increase that precedes radiographic detection by 4 weeks. Two patients with >50% tumor regressions while on ONC201 had concordant H3 K27M ctDNA burden at the onset of response and subsequent radiographic progression was preceded by increases in ctDNA 8–16 weeks prior. One patient who had prolonged stable disease had decreased H3 K27M ctDNA burden over time. Upon radiographic progression, the addition of bevacizumab with ONC201 caused a radiographic pseudoresponse, however H3 K27M ctDNA remained stable. These pilot results suggest H3 K27M ctDNA may be a sensitive and accurate biomarker of disease burden. Longitudinal evaluation of H3 K27M ctDNA in a cohort of 34 recurrent contrast-enhancing H3 K27M-mutant glioma patients while on ONC201 will be reported. Primary tumor locations range across the thalamus, cerebellum, basal ganglia, temporal lobe, and midbrain; median age is 31 years old (range 20–70).

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Modeling del(17)(p11.2p11.2) and dup(17)(p11.2p11.2) Contiguous Gene Syndromes by Chromosome Engineering in Mice: Phenotypic Consequences of Gene Dosage Imbalance

Molecular and Cellular Biology ◽

10.1128/mcb.23.10.3646-3655.2003 ◽

2003 ◽

Vol 23 (10) ◽

pp. 3646-3655 ◽

Cited By ~ 79

Author(s):

Katherina Walz ◽

Sandra Caratini-Rivera ◽

Weimin Bi ◽

Patricia Fonseca ◽

Dena L. Mansouri ◽

...

Keyword(s):

Gene Dosage ◽

Molecular Genetic ◽

Chromosome 17 ◽

Craniofacial Abnormalities ◽

Chromosome 11 ◽

Chromosome Engineering ◽

Mild Phenotype ◽

Contiguous Gene ◽

Genomic Interval ◽

Dosage Imbalance

ABSTRACT Contiguous gene syndromes (CGS) are a group of disorders associated with chromosomal rearrangements of which the phenotype is thought to result from altered copy numbers of physically linked dosage-sensitive genes. Smith-Magenis syndrome (SMS) is a CGS associated with a deletion within band p11.2 of chromosome 17. Recently, patients harboring the predicted reciprocal duplication product [dup(17)(p11.2p11.2)] have been described as having a relatively mild phenotype. By chromosomal engineering, we created rearranged chromosomes carrying the deletion [Df(11)17] or duplication [Dp(11)17] of the syntenic region on mouse chromosome 11 that spans the genomic interval commonly deleted in SMS patients. Df(11)17/+ mice exhibit craniofacial abnormalities, seizures, marked obesity, and male-specific reduced fertility. Dp(11)17/+ animals are underweight and do not have seizures, craniofacial abnormalities, or reduced fertility. Examination of Df(11)17/Dp(11)17 animals suggests that most of the observed phenotypes result from gene dosage effects. Our murine models represent a powerful tool to analyze the consequences of gene dosage imbalance in this genomic interval and to investigate the molecular genetic bases of both SMS and dup(17)(p11.2p11.2).

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Evaluation of the Influence of Genetic Variants of SLC2A9 (GLUT9) and SLC22A12 (URAT1) on the Development of Hyperuricemia and Gout

Journal of Clinical Medicine ◽

10.3390/jcm9082510 ◽

2020 ◽

Vol 9 (8) ◽

pp. 2510

Author(s):

Katerina Pavelcova ◽

Jana Bohata ◽

Marketa Pavlikova ◽

Eliska Bubenikova ◽

Karel Pavelka ◽

...

Keyword(s):

Metabolic Syndrome ◽

Uric Acid ◽

Genetic Variants ◽

Biochemical Parameters ◽

Previous Analysis ◽

Direct Sequencing ◽

Low Frequency ◽

European Population ◽

The Body ◽

Genes Encoding

Urate transporters, which are located in the kidneys, significantly affect the level of uric acid in the body. We looked at genetic variants of genes encoding the major reabsorption proteins GLUT9 (SLC2A9) and URAT1 (SLC22A12) and their association with hyperuricemia and gout. In a cohort of 250 individuals with primary hyperuricemia and gout, we used direct sequencing to examine the SLC22A12 and SLC2A9 genes. Identified variants were evaluated in relation to clinical data, biochemical parameters, metabolic syndrome criteria, and our previous analysis of the major secretory urate transporter ABCG2. We detected seven nonsynonymous variants of SLC2A9. There were no nonsynonymous variants of SLC22A12. Eleven variants of SLC2A9 and two variants of SLC22A12 were significantly more common in our cohort than in the European population (p = 0), while variants p.V282I and c.1002+78A>G had a low frequency in our cohort (p = 0). Since the association between variants and the level of uric acid was not demonstrated, the influence of variants on the development of hyperuricemia and gout should be evaluated with caution. However, consistent with the findings of other studies, our data suggest that p.V282I and c.1002+78A>G (SLC2A9) reduce the risk of gout, while p.N82N (SLC22A12) increases the risk.

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Molecular basis of the altered antigenic expression of RhD in weak D(Du) and RhC/e in RN phenotypes

Blood ◽

10.1182/blood.v87.11.4853.bloodjournal87114853 ◽

1996 ◽

Vol 87 (11) ◽

pp. 4853-4861 ◽

Cited By ~ 56

Author(s):

C Rouillac ◽

P Gane ◽

J Cartron ◽

PY Le Pennec ◽

JP Cartron ◽

...

Keyword(s):

Molecular Basis ◽

Molecular Genetic ◽

Low Frequency ◽

State Level ◽

Polymerase Chain Reaction Analysis ◽

Low Grade ◽

Molecular Genetic Basis ◽

Group Locus ◽

The Difference ◽

D Antigen

The RH blood group locus is composed of two sequence-related genes, RHD and RHCE, encoding the D, Cc, and Ee antigens in common Rh-positive phenotypes. In this report, we have analyzed the molecular basis of Rh antigens expression in weak D (Du) and RN donors, in whom there is a severe reduction of the D and C/e antigens, respectively. Genomic and transcript analysis of three unrelated low-grade weak D (Du) variants indicated that the very low expression of the D antigen is not the result of rearrangement or mutation in the coding sequence of the RHO gone. Accordingly, weak D (Du) erythrocytes should carry a normal RhD polypeptide, which is in agreement with the observation that these variants never produce anti-D antibodies. Comparative polymerase chain reaction analysis showed a lower steady-state level of RhD transcripts in weak D (Du) reticulocytes, as compared with normal RhD-positive controls, thus providing direct evidence that the difference between the D antigen of D-positive and weak D (Du) red blood cells is quantitative only. Conversely, analysis of the molecular genetic basis of the RN phenotype Indicated that the severely decreased expression of the RhC and Rhe antigens in three variants is associated with a qualitative alteration identified as a segmental DNA exchange between the RHCE and RHD genes. These genomic rearrangements, which resulted in hybrid RhCe-D-Ce proteins expressing the low frequency Rh32 but not the high incidence Rh46 antigens, involved either axon 4 alone or both exons 3 and 4. These findings show that an identical phenotypical alteration of Rh antigens (reduced expression) may result either from a quantitative or a qualitative alteration of the RH genes expression.

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Epigenetic targeting and personalized approaches for AML

Hematology ◽

10.1182/asheducation-2014.1.44 ◽

2014 ◽

Vol 2014 (1) ◽

pp. 44-51 ◽

Cited By ~ 9

Author(s):

Gail J. Roboz

Keyword(s):

Molecular Genetic ◽

Treatment Strategies ◽

Regulation Of Transcription ◽

Hematopoietic Stem ◽

Genetic Characteristics ◽

Sequencing Technologies ◽

Recurrent Mutations ◽

Genes Encoding ◽

Cell Disorder

Abstract Acute myeloid leukemia (AML) is a genetically heterogeneous clonal hematopoietic stem cell disorder and the majority of patients with AML die from their disease. The treatment paradigms for AML were developed decades ago and, although there have been improvements in the outcomes of selected younger patients and those with specific cytogenetic and molecular genetic characteristics, the overall survival for older patients remains dismal. Over the last few years, next-generation sequencing technologies have identified recurrent mutations in genes encoding proteins involved in the epigenetic regulation of transcription in most patients with AML. This discovery has led to new insights into the role of the epigenome in AML and opens the possibility of epigenetically targeted therapies. This chapter describes how epigenetic dysregulation plays a role in AML and highlights current and future treatment strategies that attempt to exploit epigenetic targets.

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Regulation of calcium signaling by polycystin-2

AJP Renal Physiology ◽

10.1152/ajprenal.00181.2003 ◽

2004 ◽

Vol 286 (6) ◽

pp. F1012-F1029 ◽

Cited By ~ 37

Author(s):

Horacio F. Cantiello

Keyword(s):

Kidney Development ◽

Cell Function ◽

Genetic Disorder ◽

Cation Channel ◽

Environmental Signals ◽

Progressive Development ◽

Channel Function ◽

Cellular Events ◽

Target Organs ◽

Genes Encoding

Autosomal dominant PKD (ADPKD) is a common lethal genetic disorder characterized by progressive development of fluid-filled cysts in the kidney and other target organs. ADPKD is caused by mutations in the PKD1 and PKD2 genes, encoding the transmembrane proteins polycystin-1 (PC1) and polycystin-2 (PC2), respectively. Although the function and putative interacting ligands of PC1 are largely unknown, recent evidence indicates that PC2 behaves as a TRP-type Ca2+-permeable nonselective cation channel. The PC2 channel is implicated in the transient increase in cytosolic Ca2+ in renal epithelial cells and may be linked to the activation of subsequent signaling pathways. Recent studies also indicate that PC1 functionally interacts with PC2 such that the PC1-PC2 channel complex is an obligatory novel signaling pathway implicated in the transduction of environmental signals into cellular events. The present review purposely avoids issues of regulation of PC2 expression and trafficking and focuses instead on the evidence for the TRP-type cation channel function of PC2. How its role as a cation channel may unmask mechanisms that trigger Ca2+ transport and regulation is the focus of attention. PC2 channel function may be essential in renal cell function and kidney development. Nonrenal-targeted expression of PC2 and related proteins, including the cardiovascular system, also suggests previously unforeseeable roles in signal transduction.

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Reflection of circumferential modes in a choked nozzle

Journal of Fluid Mechanics ◽

10.1017/s0022112002001428 ◽

2002 ◽

Vol 467 ◽

pp. 215-239 ◽

Cited By ~ 90

Author(s):

S. R. STOW ◽

A. P. DOWLING ◽

T. P. HYNES

Keyword(s):

Acoustic Wave ◽

Low Frequency ◽

Effective Length ◽

Mean Flow ◽

Small Perturbations ◽

Choked Flow ◽

First Case ◽

Propagating Waves ◽

Flow Through ◽

Good Agreement

Small perturbations of a choked flow through a thin annular nozzle are investigated. Two cases are considered, corresponding to a ‘choked outlet’ and a ‘choked inlet’ respectively. For the first case, either an acoustic or entropy or vorticity wave is assumed to be travelling downstream towards the nozzle contraction. An asymptotic analysis for low frequency is used to find the reflected acoustic wave that is created. The boundary condition found by Marble & Candel (1977) for a compact choked nozzle is shown to apply to first order, even for circumferentially varying waves. The next-order correction can be expressed as an ‘effective length’ dependent on the mean flow (and hence the particular geometry of the nozzle) in a quantifiable way.For the second case, an acoustic wave propagates upstream and is reflected from a convergent–divergent nozzle. A normal shock is assumed to be present. By considering the interaction of the shock's position and flow perturbations, the reflected propagating waves are found for a compact nozzle. It is shown that a significant entropy disturbance is produced even when the shock is weak, and that for circumferential modes a vorticity wave is also present. Numerical calculations are conducted using a sample geometry and good agreement with the analysis is found at low frequency in both cases, and the range of validity of the asymptotic theory is determined.

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