scholarly journals Mutations in the genes encoding for leptin and its mediators: induction of obesity with various concomitant pathological conditions

2013 ◽  
Vol 59 (2) ◽  
pp. 49-59
Author(s):  
Iu A Pankov
Keyword(s):  
Severe Obesity ◽  
Donor Site ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
Pathological Changes ◽  
Homozygous State ◽  
Base Pairs ◽  
Genes Encoding ◽  
Adenohypophyseal Hormones ◽  
Severe Pathology

g15384delG(G133fsX15), c.215T⇒C(p.L72S), c.309C⇒A(p.N103K), c.313C⇒T(p.R105W), c.422C⇒G(p.S141C), c.104_106delTCA, c.481_482delC⇒T, and c.135del13bp mutations in LEP in the homozygous state are known to be associated with the early onset of severe obesity and disturbances of many physiological functions. Similar pathological changes are induced by mutations in LEPR, such as G⇒A substitution in the splicing donor site, deletions of 4 and 11 base pairs in the 5'-terminus of cDNA, deletion of 66 bp in the CRH domain of LEPR, compound deletion of 1 base pair in the 5'-terminus/p.R612H, and missense mutations P316T, A409E, W664R, and H684P. Disturbances in LEP and LEPR expression in homozygous subjects are associated with severe obesity, retarded sexual development, insulin resistance, disordered secretion of adenohypophyseal hormones, and immunodeficiency. Mutations in LEP cause more serious pathological changes than LEPR mutations. In the homozygous state, mutations in POMC, such as 3804C⇒A, 6906delC, 6922insC, and compound heterozygous mutations 7134delG/7013G⇒T, 6996del/6851A⇒T, 3804CA/7100insGG are associated in man with morbid obesity and acute adrenal cortical insufficiency. In the heterozygous state, these mutations predispose to obesity in the absence of concomitant disorders. Mutations in MC4R are the most common cause of obesity. They are known to induce severe pathology in homozygous subjects but significantly milder disturbances of adipose tissue metabolism in heterozygotes. In both cases, obesity is not accompanied by serious disturbances of other functions.

scholarly journals OR22-05 Rare Biallelic Variants in Obesity-Related Genes in the Madrid Pediatric Obesity Cohort

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Gabriel Á Martos-Moreno ◽  
Ida Hatoum Moeller ◽  
Álvaro Martín-Rivada ◽  
Luis A Pérez-Jurado ◽  
Jesús Argente
Keyword(s):  
Childhood Obesity ◽  
Severe Obesity ◽  
Genetic Disorders ◽  
Compound Heterozygous ◽  
Homozygous Mutation ◽  
Loss Of Function ◽  
Protein Coding ◽  
Pathogenic Variants ◽  
Genes Encoding ◽  
Biallelic Mutations

Abstract BACKGROUND: Obesity is a heterogenous disease resulting from environmental and genetic factors and is characterized by disordered energy balance, regulated in part by the hypothalamic melanocortin-4 receptor (MC4R), including neuronal ciliary assembly and trafficking pathways.1 Rare loss-of-function variants in genes encoding components of this pathway are associated with severe obesity and hyperphagia, with or without additional features.2 However, such rare genetic disorders may be underestimated due to a lack of genetic screening in individuals with severe obesity.3 Our objective was to identify and characterize rare genetic variants in a Spanish population from Madrid with childhood obesity. Methods: This analysis was conducted from a prospectively-collected cohort of children with obesity, generally with a BMI>+3DS. Participants were sequenced for 35 obesity-related genes, including 23 genes related to Bardet-Biedl (BBS) and Alström syndromes, plus an additional 12 genes associated with non-syndromic, monogenic causes of obesity, to identify individuals with rare (<1% frequency in gnomAD) potentially biallelic (homozygous and compound heterozygous) non-synonymous variants in protein-coding regions. Results: Of the 1019 Spanish patients with obesity, 493 (48.4%) were female and the mean age and BMI were 10.41 ± 3.38 years and 4.38 ± 1.76 SDS (79.8% above +3 SDS), respectively. We identified 26 rare potentially biallelic variants in 25 unique individuals, including 2 individuals with homozygous variants in POMC, 3 individuals with two variants in SRC1, one individual with two variants in ADCY3, and one individual with a homozygous mutation in LEP. In addition, we identified 18 individuals with biallelic mutations in one of 23 BBS or ALMS1 genes, including two individuals with known pathogenic variants and clinically confirmed BBS. Conclusions: Rare and potentially biallelic sequence variants were identified in 25 individuals with childhood obesity. These results support the use of genetic testing for individuals with severe obesity who may be candidates for specific clinical interventions or additional targeted therapies.

Anti-Myelin Oligodendrocyte Glycoprotein Encephalomyelitis and Extensive Longitudinal Transverse Myelitis Associated with Compound Heterozygous NLRP3 Missense Mutations in a Young Child

2020 ◽  
Author(s):  
Deirdre O'Sullivan ◽  
Michael Moore ◽  
Susan Byrne ◽  
Andreas O. Reiff ◽  
Susanna Felsenstein
Keyword(s):  
Young Child ◽  
Genetic Basis ◽  
Transverse Myelitis ◽  
Acute Disseminated Encephalomyelitis ◽  
Myelin Oligodendrocyte Glycoprotein ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
Childhood Onset

AbstractAcute disseminated encephalomyelitis in association with extensive longitudinal transverse myelitis is reported in a young child with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody with heterozygous NLRP3 missense mutations; p.(Arg488Lys) and p.(Ser159Ile). This case may well present an exceptional coincidence, but may describe a yet unrecognized feature of the spectrum of childhood onset cryopyrinopathies that contribute to the understanding of the genetic basis for anti-MOG antibody positive encephalomyelitis. Based on this observation, a larger scale study investigating the role of NLRP3 and other inflammasomes in this entity would provide important pathophysiological insights and potentially novel avenues for treatment.

Molecular basis of ciliary defects caused by compound heterozygous IFT144/WDR19 mutations found in cranioectodermal dysplasia

2021 ◽  
Author(s):  
Yamato Ishida ◽  
Takuya Kobayashi ◽  
Shuhei Chiba ◽  
Yohei Katoh ◽  
Kazuhisa Nakayama
Keyword(s):  
Protein Trafficking ◽  
Primary Cilia ◽  
Intraflagellar Transport ◽  
Missense Variant ◽  
Cellular Level ◽  
Compound Heterozygous ◽  
Hypomorphic Allele ◽  
Genes Encoding ◽  
Specific Proteins ◽  
Compound Heterozygous Mutations

Abstract Primary cilia contain specific proteins to achieve their functions as cellular antennae. Ciliary protein trafficking is mediated by the intraflagellar transport (IFT) machinery containing the IFT-A and IFT-B complexes. Mutations in genes encoding the IFT-A subunits (IFT43, IFT121/WDR35, IFT122, IFT139/TTC21B, IFT140, and IFT144/WDR19) often result in skeletal ciliopathies, including cranioectodermal dysplasia (CED). We here characterized the molecular and cellular defects of CED caused by compound heterozygous mutations in IFT144 [the missense variant IFT144(L710S) and the nonsense variant IFT144(R1103*)]. These two variants were distinct with regard to their interactions with other IFT-A subunits and with the IFT-B complex. When exogenously expressed in IFT144-knockout (KO) cells, IFT144(L710S) as well as IFT144(WT) rescued both moderately compromised ciliogenesis and the abnormal localization of ciliary proteins. As the homozygous IFT144(L710S) mutation was found to cause autosomal recessive retinitis pigmentosa, IFT144(L710S) is likely to be hypomorphic at the cellular level. In striking contrast, the exogenous expression of IFT144(R1103*) in IFT144-KO cells exacerbated the ciliogenesis defects. The expression of IFT144(R1103*) together with IFT144(WT) restored the abnormal phenotypes of IFT144-KO cells. However, the coexpression of IFT144(R1103*) with the hypomorphic IFT144(L710S) variant in IFT144-KO cells, which mimics the genotype of compound heterozygous CED patients, resulted in severe ciliogenesis defects. Taken together, these observations demonstrate that compound heterozygous mutations in IFT144 cause severe ciliary defects via a complicated mechanism, where one allele can cause severe ciliary defects when combined with a hypomorphic allele.

scholarly journals Genetic Analysis of Colistin Resistance in Salmonella enterica Serovar Typhimurium

2009 ◽  
Vol 53 (6) ◽  
pp. 2298-2305 ◽  
Author(s):  
Song Sun ◽  
Aurel Negrea ◽  
Mikael Rhen ◽  
Dan I. Andersson
Keyword(s):  
Mutation Rate ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Regulatory System ◽  
Clinical Settings ◽  
Missense Mutations ◽  
Regulator Protein ◽  
Serovar Typhimurium ◽  
Sensor Kinases ◽  
Genes Encoding

ABSTRACT Colistin is a cyclic cationic peptide that kills gram-negative bacteria by interacting with and disrupting the outer membrane. We isolated 44 independent mutants in Salmonella enterica serovar Typhimurium with reduced susceptibility to colistin and identified 27 different missense mutations located in the pmrA and pmrB genes (encoding the regulator and sensor of a two-component regulatory system) that conferred increased resistance. By comparison of the two homologous sensor kinases, PmrB and EnvZ, the 22 missense mutations identified in pmrB were shown to be located in four different structural domains of the protein. All five pmrA mutations were located in the phosphate receiver domain of the regulator protein. The mutants appeared at a mutation rate of 0.6 × 10−6 per cell per generation. The MICs of colistin for the mutants increased 2- to 35-fold, and the extent of killing was reduced several orders of magnitude compared to the susceptible strain. The growth rates of the mutants were slightly reduced in both rich medium and M9-glycerol minimal medium, whereas growth in mice appeared unaffected by the pmrA and pmrB mutations. The low fitness costs and the high mutation rate suggest that mutants with reduced susceptibility to colistin could emerge in clinical settings.

scholarly journals Novel compound heterozygous EYS variants may be associated with arRP in a large Chinese pedigree

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Chunli Wei ◽  
Ting Xiao ◽  
Jingliang Cheng ◽  
Jiewen Fu ◽  
Qi Zhou ◽  
...  
Keyword(s):  
Novel Mutation ◽  
Gene Mutations ◽  
Chinese Family ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
The Novel ◽  
Pathogenic Variants ◽  
Pathogenic Genes ◽  
Compound Heterozygous Variants ◽  
Normal Controls

Abstract As a genetically heterogeneous ocular dystrophy, gene mutations with autosomal recessive retinitis pigmentosa (arRP) in patients have not been well described. We aimed to detect the disease-causing genes and variants in a Chinese arRP family. In the present study, a large Chinese pedigree consisting of 31 members including a proband and another two patients was recruited; clinical examinations were conducted; next-generation sequencing using a gene panel was used for identifying pathogenic genes, and Sanger sequencing was performed for verification of mutations. Novel compound heterozygous variants c.G2504A (p.C835Y) and c.G6557A (p.G2186E) for the EYS gene were identified, which co-segregated with the clinical RP phenotypes. Sequencing of 100 ethnically matched normal controls didn’t found these mutations in EYS. Therefore, our study identified pathogenic variants in EYS that may cause arRP in this Chinese family. This is the first study to reveal the novel mutation in the EYS gene (c.G2504A, p.C835Y), extending its mutation spectrum. Thus, the EYS c.G2504A (p.C835Y) and c.G6557A (p.G2186E) variants may be the disease-causing missense mutations for RP in this large arRP family. These findings should be helpful for molecular diagnosis, genetic counseling and clinical management of arRP disease.

scholarly journals A Budding Yeast Model for Human Disease Mutations in the EXOSC2 Cap Subunit of the RNA Exosome

2020 ◽  
Author(s):  
Maria C. Sterrett ◽  
Liz Enyenihi ◽  
Sara W. Leung ◽  
Laurie Hess ◽  
Sarah E. Strassler ◽  
...  
Keyword(s):  
Amino Acid ◽  
Budding Yeast ◽  
Amino Acid Substitutions ◽  
Missense Mutations ◽  
Subunit Gene ◽  
Rna Targets ◽  
Genes Encoding ◽  
Rna Exosome ◽  
Transcriptomic Changes

AbstractRNA exosomopathies, a growing family of tissue-specific diseases, are linked to missense mutations in genes encoding the structural subunits of the conserved 10-subunit exoribonuclease complex, the RNA exosome. Such mutations in the cap subunit gene EXOSC2 cause the novel syndrome SHRF (Short stature, Hearing loss, Retinitis pigmentosa and distinctive Facies). In contrast, exosomopathy mutations in the cap subunit gene EXOSC3 cause pontocerebellar hypoplasia type 1b (PCH1b). Though having strikingly different disease pathologies, EXOSC2 and EXOSC3 exosomopathy mutations result in amino acid substitutions in similar, conserved domains of the cap subunits, suggesting that these exosomopathy mutations have distinct consequences for RNA exosome function. We generated the first in vivo model of the SHRF pathogenic amino acid substitutions using budding yeast by introducing the EXOSC2 mutations in the orthologous S. cerevisiae gene RRP4. The resulting rrp4 mutant cells have defects in cell growth and RNA exosome function. We detect significant transcriptomic changes in both coding and non-coding RNAs in the rrp4 variant, rrp4-G226D, which models EXOSC2 p.Gly198Asp. Comparing this rrp4-G226D mutant to the previously studied S. cerevisiae model of EXOSC3 PCH1b mutation, rrp40-W195R, reveals that these mutants have disparate effects on certain RNA targets, providing the first evidence for different mechanistic consequences of these exosomopathy mutations. Congruently, we detect specific negative genetic interactions between RNA exosome cofactor mutants and rrp4-G226D but not rrp40-W195R. These data provide insight into how SHRF mutations could alter the function of the RNA exosome and allow the first direct comparison of exosomopathy mutations that cause distinct pathologies.

scholarly journals Non-spherocytic hemolytic anemia caused by erythrocyte pyruvate kinase defiiency: the analysis of genetic defects in pediatric patients, living in Russian Federation

2021 ◽  
Vol 20 (2) ◽  
pp. 84-96
Author(s):  
E. A. Cherniak ◽  
N. E. Sokolova ◽  
K. V. Semiglazova ◽  
I. N. Lavrentyeva ◽  
E. K. Donush ◽  
...  
Keyword(s):  
Medical Research ◽  
Hemolytic Anemia ◽  
Research Center ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
Pediatric Hematology ◽  
Transfusion Independence ◽  
National Medical ◽  
Retrospective Data Analysis ◽  
Minimum Age

The article presents retrospective data analysis of a cohort of patients with PKD (n = 41 patients, aged 4 months – 26,5 years, median of age – 5 years 1 month) who were examined at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology for unspecifid hereditary hemolytic anemia during the period 2013–2020. The study was approved by the Independent Ethics Committee of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. In all patients, the diagnosis was confimed by Next Generation sequencing (NGS). The homozygous mutations in the PKLR gene were found in 10 patients (24.39%), compound heterozygous mutations in 31 patients (75.61%), 77.78% of them were missense mutations. Gender distribution (male:female) was 1:1.73. At least once transfusion of erythrocyte suspension was required to 40 (97.56%) patients. The minimum age at the time of the debut of transfusion dependence was the fist day of life, the maximum was 4 years. Exchange blood transfusion was performed in 13 children, severe normocytic hyperregenerative anemia with transfusion of red blood cells in the fist days of life was noted in 12 children, at the 1st month of life – in 9 children, at the 2nd month of life – in 8 children, at the 3rd month – in 6 children, at the 5th month – in 2 children, at the 1st year – in 1 child, and 2 children underwent single transfusions on the background of infectious episodes at 3 and 4 years respectively. Splenectomy due to high transfusion dependence was performed in 10 patients: transfusion independence was achieved in 5 patients, in 5 – an increase in the interval between blood transfusions. Median of surgical intervention (9 patients): 7 years 4 months, minimum age – 1 year 4 months, maximum – 14 years 4 months. In total, 36 genotypes were described in 41 patients, among them were: c.1529G>A in 3 patients, c.1137_1139del / c.1456C>T – in 2 patients, c.1079G>A/c.1529G>A in 2 patients, c.1130T>C/c.1456C>T in 2 patients, other genotypes occurred once. Two mutations were the most frequent: c.1456C>T (16.67%) and c.1529G>A (16.67%). 19 (46,34%) of patients had previously not described mutations.

Effects of SEL-12 presenilin on LIN-12 localization and function in Caenorhabditis elegans

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3599-3606 ◽  
Author(s):  
D. Levitan ◽  
I. Greenwald
Keyword(s):  
Plasma Membranes ◽  
General Factor ◽  
Missense Mutations ◽  
Protein Activity ◽  
App Processing ◽  
Notch Activity ◽  
C Elegans ◽  
Vulval Precursor Cells ◽  
Genes Encoding ◽  
And Function

Presenilins have been implicated in the development of Alzheimer's disease and in facilitating LIN-12/Notch activity. Here, we use genetic methods to explore the relationship between C. elegans LIN-12 and SEL-12 presenilin. Reducing sel-12 activity can suppress the effects of elevated lin-12 activity when LIN-12 is activated by missense mutations but not when LIN-12 is activated by removal of the extracellular and transmembrane domains. These results suggest that SEL-12 does not function downstream of activated LIN-12. An active SEL-12::GFP hybrid protein accumulates in the perinuclear region of the vulval precursor cells (VPCs) of living hermaphrodites, consistent with a localization in endoplasmic reticulum/Golgi membranes; when sel-12 activity is reduced, less LIN-12 protein accumulates in the plasma membranes of the VPCs. Together with the genetic interactions between lin-12 and sel-12, these observations suggest a role for SEL-12 in LIN-12 processing or trafficking. However, SEL-12 does not appear to be a general factor that influences membrane protein activity, since reducing sel-12 activity does not suppress or enhance hypomorphic mutations in other genes encoding membrane proteins. We discuss potential parallels for the role of SEL-12/presenilin in facilitating LIN-12/Notch activity and in amyloid precursor protein (APP) processing.

The heart in neuromuscular disease: primary mitochondrial diseases

ESC CardioMed ◽  
2018 ◽  
pp. 1528-1530
Author(s):  
Denis Duboc
Keyword(s):  
Neuromuscular Disease ◽  
Nuclear Dna ◽  
Single Cells ◽  
Mitochondrial Diseases ◽  
Respiratory Chain Complexes ◽  
Base Pairs ◽  
Daughter Cells ◽  
Dna Molecule ◽  
Chain Complexes ◽  
Genes Encoding

Mitochondria are responsible for energy production in most eukaryotic cells. Each cell contains at least one mitochondrion and every mitochondrion contains two to ten copies of a circular DNA molecule (mitochondrial DNA or mtDNA). Cardiomyocytes contain approximately 10,000 mtDNA copies. MtDNA is composed of around 16,500 base pairs and 37 genes encoding 13 subunits of the respiratory chain complexes I, III, IV, and V, 22 mitochondrial tRNAs and 2 rRNAs. With each cell division, mitochondria and mtDNA are randomly distributed to daughter cells. In humans, mitochondria are inherited exclusively from the mother. In healthy people mtDNA copies are usually identical at birth (homoplasmy) but with ageing, mtDNA is particularly prone to somatic mutation because, unlike nuclear DNA, it is continuously replicated, even in non-dividing tissues such as myocardium. This can lead to the propagation of somatic mutations within single cells by a process called clonal expansion. In addition, mtDNA lacks an extensive DNA repair mechanism.

scholarly journals Multiple Rare Risk Coding Variants in Postsynaptic Density-Related Genes Associated With Schizophrenia Susceptibility

2020 ◽  
Vol 11 ◽  
Author(s):  
Tsung-Ming Hu ◽  
Ying-Chieh Wang ◽  
Chia-Liang Wu ◽  
Shih-Hsin Hsu ◽  
Hsin-Yao Tsai ◽  
...  
Keyword(s):  
Protein Function ◽  
Cultured Cells ◽  
Postsynaptic Density ◽  
Psychiatric History ◽  
Missense Mutations ◽  
Genes Encoding ◽  
Schizophrenic Patients ◽  
Synaptic Receptors ◽  
Related Proteins ◽  
Coding Variants

ObjectiveSchizophrenia is a chronic debilitating neurobiological disorder of aberrant synaptic connectivity and synaptogenesis. Postsynaptic density (PSD)–related proteins in N-methyl-D-aspartate receptor–postsynaptic signaling complexes are crucial to regulating the synaptic transmission and functions of various synaptic receptors. This study examined the role of PSD-related genes in susceptibility to schizophrenia.MethodsWe resequenced 18 genes encoding the disks large-associated protein (DLGAP), HOMER, neuroligin (NLGN), neurexin, and SH3 and multiple ankyrin repeat domains (SHANK) protein families in 98 schizophrenic patients with family psychiatric history using semiconductor sequencing. We analyzed the protein function of the identified rare schizophrenia-associated mutants via immunoblotting and immunocytochemistry.ResultsWe identified 50 missense heterozygous mutations in 98 schizophrenic patients with family psychiatric history, and in silico analysis revealed some as damaging or pathological to the protein function. Ten missense mutations were absent from the dbSNP database, the gnomAD (non-neuro) dataset, and 1,517 healthy controls from Taiwan BioBank. Immunoblotting revealed eight missense mutants with altered protein expressions in cultured cells compared with the wild type.ConclusionOur findings suggest that PSD-related genes, especially the NLGN, SHANK, and DLGAP families, harbor rare functional mutations that might alter protein expression in some patients with schizophrenia, supporting contributing rare coding variants into the genetic architecture of schizophrenia.

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