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Keywords = KCNQ4 c.546C>G

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18 pages, 1105 KB  
Article
lncRNAs as Biomarkers of Hepatocellular Carcinoma Risk and Liver Damage in Advanced Chronic Hepatitis C
by Driéle B. dos Santos, Geysson J. Fernandez, Letícia T. Silva, Giovanni F. Silva, Estela O. Lima, Aline F. Galvani, Guilherme L. Pereira and Adriana C. Ferrasi
Curr. Issues Mol. Biol. 2025, 47(5), 348; https://doi.org/10.3390/cimb47050348 - 10 May 2025
Viewed by 1069
Abstract
Background/Objectives: LncRNAs have emerged as promising biomarkers due to their role in gene regulation of carcinogenesis and presence in biological fluids. Liquid biopsies offer a less invasive alternative to tissue biopsies, improving early cancer diagnosis and surveillance. Hepatocellular carcinoma (HCC) is among the [...] Read more.
Background/Objectives: LncRNAs have emerged as promising biomarkers due to their role in gene regulation of carcinogenesis and presence in biological fluids. Liquid biopsies offer a less invasive alternative to tissue biopsies, improving early cancer diagnosis and surveillance. Hepatocellular carcinoma (HCC) is among the most lethal and prevalent cancers. Late diagnoses contribute to poor prognosis, particularly in chronic hepatitis C (CHC) patients, which is a major risk factor for HCC. Tissue biopsies for HCC diagnosis pose risks, including tumor dissemination, highlighting the urgent need for noninvasive biomarkers. Several lncRNAs are deregulated in HCC and may be potential markers for assessing HCC risk in CHC. This study evaluated seven lncRNAs as plasma biomarkers for HCC risk in CHC. Methods: lncRNA expression was analyzed by RT-qPCR in three groups: CHC patients who developed HCC within a 5-year follow-up (HCCpos), CHC patients who did not develop HCC within a 5-year follow-up (HCCneg), and healthy blood donors (CG). Results: This study found that plasma lncRNAs HULC and RP11-731F5.2 are potential biomarkers for HCC risk, while RP11-731F5.2 and KCNQ1OT1 may serve as noninvasive biomarkers for liver damage due to HCV infection. Conclusions: These findings highlight the potential of lncRNAs in enhancing early diagnosis and monitoring of HCC in CHC patients. Full article
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12 pages, 2306 KB  
Article
Novel KCNQ2 Variants Related to a Variable Phenotypic Spectrum Ranging from Epilepsy with Auditory Features to Severe Developmental and Epileptic Encephalopathies
by Mariagrazia Talarico, Radha Procopio, Monica Gagliardi, Maria Chiara Sarubbi, Francesco Fortunato, Ilaria Sammarra, Gaetan Lesca, Donatella Malanga, Grazia Annesi and Antonio Gambardella
Int. J. Mol. Sci. 2025, 26(1), 295; https://doi.org/10.3390/ijms26010295 - 31 Dec 2024
Viewed by 1687
Abstract
Pathogenic KCNQ2 variants are associated with neonatal epilepsies, ranging from self-limited neonatal epilepsy to KCNQ2–developmental and epileptic encephalopathy (DEE). In this study, next-generation sequencing was performed, applying a panel of 142 epilepsy genes on three unrelated individuals and affected family members, showing [...] Read more.
Pathogenic KCNQ2 variants are associated with neonatal epilepsies, ranging from self-limited neonatal epilepsy to KCNQ2–developmental and epileptic encephalopathy (DEE). In this study, next-generation sequencing was performed, applying a panel of 142 epilepsy genes on three unrelated individuals and affected family members, showing a wide variability in the epileptic spectrum. The genetic analysis revealed two likely pathogenic missense variants (c.1378G>A and c.2251T>G) and the already-reported pathogenic splice site (c.1631+1G>A) in KCNQ2 (HGNC:6296). The phenotypes observed in the affected members of family 1, which shared the c.2251T>G variant, were epilepsy with auditory features (EAFs), focal epilepsy, and generalized epilepsy, and none of them suffered from neonatal seizures. The gene panel contained further genes related to EAFs (LGI1, RELN, SCN1A, and DEPDC5), which were tested with negative results. The phenotypes observed in family 2 members, sharing the splice site variant, were neonatal seizures and focal epilepsy in childhood. The last unrelated proband, harboring the de novo missense c.1378G>A, presented a clinical phenotype consistent with DEE. In conclusion, we identified two unreported KCNQ2 variants, and report a proband with EAFs and individuals without typical KCNQ2 neonatal seizures. Our study underscores the extreme variability in the phenotypic spectrum of KCNQ2-related epilepsies and unveils the prospect of its inclusion in screening panels for EAFs. Full article
(This article belongs to the Special Issue From Molecular Insights to Novel Therapies: Neurological Diseases)
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16 pages, 1236 KB  
Article
Deregulated Long Non-Coding RNAs (lncRNA) as Promising Biomarkers in Hidradenitis Suppurativa
by Uppala Radhakrishna, Uppala Ratnamala, Devendrasinh D. Jhala, Lavanya V. Uppala, Aaren Vedangi, Nazia Saiyed, Maulikkumar Patel, Sushma R. Shah, Rakesh M. Rawal, Gregor B. E. Jemec, Tommaso Mazza, Gianluigi Mazzoccoli and Giovanni Damiani
J. Clin. Med. 2024, 13(10), 3016; https://doi.org/10.3390/jcm13103016 - 20 May 2024
Cited by 7 | Viewed by 2451
Abstract
Background/Objectives: In recent times, epigenetics alterations in Hidradenitis suppurativa (HS) have been explored and exploited translationally to guide investigation of new therapeutic approaches. On the other hand, long noncoding RNAs (LncRNAs), main regulators of the epigenetic status of the human genome, have been [...] Read more.
Background/Objectives: In recent times, epigenetics alterations in Hidradenitis suppurativa (HS) have been explored and exploited translationally to guide investigation of new therapeutic approaches. On the other hand, long noncoding RNAs (LncRNAs), main regulators of the epigenetic status of the human genome, have been scarcely investigated, notwithstanding their potential relevance in broad pathogenesis comprehension. Here, we aim to explore the methylation pattern of lncRNAs in HS. Methods: In this case-control study, 24 HS patients and age-, sex- and BMI-matched controls were analyzed to characterize the methylome of lncRNA genes in peripheral blood cells. Gene ontology analysis (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, protein–protein interaction (PPI) network, and MCODE analysis were performed. Results: A set of fifteen lncRNA genes exhibited significantly differential methylation patterns, with ten of them showing hypomethylation and five displaying hypermethylation at specific CpG sites. The hypomethylated lncRNA genes were DLEU2, MESTIT1, CASC2, TUG1, KCNQ1DN, PSORS1C3, PCA3, DSCR8, RFPL1S, and PVT1, while the hypermethylated ones were HAR1A, FAM66B, SNHG9, HCG9, and HCP5. These lncRNA genes have been linked to various important biological processes, including cell proliferation, apoptosis, inflammation, chronic inflammatory skin diseases, and wound healing. Their altered methylation status suggests potential roles in regulating these processes, and may contribute to HS pathogenesis and healing mechanisms. Conclusions: This study revealed an interesting dysregulation pattern of definite lncRNAs in the methylome which is linked to both the development of HS and its comorbidities. Epigenetically altered lncRNAs genes could represent useful biomarkers, and could help in guiding innovative treatment strategies. Full article
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9 pages, 260 KB  
Article
Association between Single Nucleotide Polymorphisms of PRKD1 and KCNQ3 Gene and Milk Quality Traits in Gannan Yak (Bos grunniens)
by Xiaoyong Ma, Guowu Yang, Juanxiang Zhang, Rong Ma, Jinwei Shen, Fen Feng, Daoning Yu, Chun Huang, Xiaoming Ma, Yongfu La, Xiaoyun Wu, Xian Guo, Min Chu, Ping Yan and Chunnian Liang
Foods 2024, 13(5), 781; https://doi.org/10.3390/foods13050781 - 2 Mar 2024
Cited by 4 | Viewed by 1900
Abstract
Protein kinase D1 (PRKD1) functions primarily in normal mammary cells, and the potassium voltage-gated channel subfamily Q member 3 (KCNQ3) gene plays an important role in controlling membrane potential and neuronal excitability, it has been found that this particular gene is [...] Read more.
Protein kinase D1 (PRKD1) functions primarily in normal mammary cells, and the potassium voltage-gated channel subfamily Q member 3 (KCNQ3) gene plays an important role in controlling membrane potential and neuronal excitability, it has been found that this particular gene is linked to the percentage of milk fat in dairy cows. The purpose of this study was to investigate the relationship between nucleotide polymorphisms (SNPs) of PRKD1 and KCNQ3 genes and the milk quality of Gannan yak and to find molecular marker sites that may be used for milk quality breeding of Gannan yak. Three new SNPs were detected in the PRKD1 (g.283,619T>C, g.283,659C>A) and KCNQ3 gene (g.133,741T>C) of 172 Gannan lactating female yaks by Illumina yak cGPS 7K liquid-phase microarray technology. Milk composition was analyzed using a MilkoScanTM milk composition analyzer. We found that the mutations of these three loci significantly improved the lactose, milk fat, casein, protein, non-fat milk solid (SNF) content and acidity of Gannan yaks. The lactose content of the TC heterozygous genotype population at g.283,619T>C locus was significantly higher than that of the TT wild-type population (p < 0.05); the milk fat content of the CA heterozygous genotype population at g.283,659C>A locus was significantly higher than that of the CC wild-type and AA mutant populations (p < 0.05); the casein, protein and acidity of the CC mutant and TC heterozygous groups at the g.133,741T>C locus were significantly higher than those of the wild type (p < 0.05), and the SNF of the TC heterozygous group was significantly higher than that of the mutant group (p < 0.05). The results showed that PRKD1 and KCNQ3 genes could be used as candidate genes affecting the milk traits of Gannan yak. Full article
(This article belongs to the Special Issue New Insights into Milk and Dairy Products: Quality and Sustainability)
23 pages, 9180 KB  
Article
Studying Conformational Properties of Transmembrane Domain of KCNE3 in a Lipid Bilayer Membrane Using Molecular Dynamics Simulations
by Anna Clara Miranda Moura, Isaac K. Asare, Mateo Fernandez Cruz, Antonio Javier Franco Aguado, Kaeleigh Dyan Tuck, Conner C. Campbell, Matthew W. Scheyer, Ikponwmosa Obaseki, Steve Alston, Andrea N. Kravats, Charles R. Sanders, Gary A. Lorigan and Indra D. Sahu
Membranes 2024, 14(2), 45; https://doi.org/10.3390/membranes14020045 - 4 Feb 2024
Cited by 3 | Viewed by 3193
Abstract
KCNE3 is a single-pass integral membrane protein that regulates numerous voltage-gated potassium channel functions such as KCNQ1. Previous solution NMR studies suggested a moderate degree of curved α-helical structure in the transmembrane domain (TMD) of KCNE3 in lyso-myristoylphosphatidylcholine (LMPC) micelles and isotropic bicelles [...] Read more.
KCNE3 is a single-pass integral membrane protein that regulates numerous voltage-gated potassium channel functions such as KCNQ1. Previous solution NMR studies suggested a moderate degree of curved α-helical structure in the transmembrane domain (TMD) of KCNE3 in lyso-myristoylphosphatidylcholine (LMPC) micelles and isotropic bicelles with the residues T71, S74 and G78 situated along the concave face of the curved helix. During the interaction of KCNE3 and KCNQ1, KCNE3 pushes its transmembrane domain against KCNQ1 to lock the voltage sensor in its depolarized conformation. A cryo-EM study of KCNE3 complexed with KCNQ1 in nanodiscs suggested a deviation of the KCNE3 structure from its independent structure in isotropic bicelles. Despite the biological significance of KCNE3 TMD, the conformational properties of KCNE3 are poorly understood. Here, all atom molecular dynamics (MD) simulations were utilized to investigate the conformational dynamics of the transmembrane domain of KCNE3 in a lipid bilayer containing a mixture of POPC and POPG lipids (3:1). Further, the effect of the interaction impairing mutations (V72A, I76A and F68A) on the conformational properties of the KCNE3 TMD in lipid bilayers was investigated. Our MD simulation results suggest that the KCNE3 TMD adopts a nearly linear α helical structural conformation in POPC-POPG lipid bilayers. Additionally, the results showed no significant change in the nearly linear α-helical conformation of KCNE3 TMD in the presence of interaction impairing mutations within the sampled time frame. The KCNE3 TMD is more stable with lower flexibility in comparison to the N-terminal and C-terminal of KCNE3 in lipid bilayers. The overall conformational flexibility of KCNE3 also varies in the presence of the interaction-impairing mutations. The MD simulation data further suggest that the membrane bilayer width is similar for wild-type KCNE3 and KCNE3 containing mutations. The Z-distance measurement data revealed that the TMD residue site A69 is close to the lipid bilayer center, and residue sites S57 and S82 are close to the surfaces of the lipid bilayer membrane for wild-type KCNE3 and KCNE3 containing interaction-impairing mutations. These results agree with earlier KCNE3 biophysical studies. The results of these MD simulations will provide complementary data to the experimental outcomes of KCNE3 to help understand its conformational dynamic properties in a more native lipid bilayer environment. Full article
(This article belongs to the Special Issue Analytical Sciences of/with Bio(mimetic) Membranes (Volume II))
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10 pages, 939 KB  
Brief Report
Shared Genetics between Age at Menarche and Type 2 Diabetes Mellitus: Genome-Wide Genetic Correlation Study
by Yuan-Fang Cheng, Cheng-Yi Yang and Meng-Che Tsai
Biomedicines 2024, 12(1), 157; https://doi.org/10.3390/biomedicines12010157 - 11 Jan 2024
Cited by 2 | Viewed by 2028
Abstract
Background: Age at menarche (AAM) has been associated with type 2 diabetes mellitus (T2DM). However, little is known about their shared heritability. Methods: Our data comes from the Taiwan Biobank. Genome-wide association studies (GWASs) were conducted to identify single-nucleotide polymorphisms (SNPs) related to [...] Read more.
Background: Age at menarche (AAM) has been associated with type 2 diabetes mellitus (T2DM). However, little is known about their shared heritability. Methods: Our data comes from the Taiwan Biobank. Genome-wide association studies (GWASs) were conducted to identify single-nucleotide polymorphisms (SNPs) related to AAM-, T2DM-, and T2DM-related phenotypes, such as body fat percentage (BFP), fasting blood glucose (FBG), and hemoglobin A1C (HbA1C). Further, the conditional false discovery rate (cFDR) method was applied to examine the shared genetic signals. Results: Conditioning on AAM, Quantile-quantile plots showed an earlier departure from the diagonal line among SNPs associated with BFP and FBG, indicating pleiotropic enrichments among AAM and these traits. Further, the cFDR analysis found 39 independent pleiotropic loci that may underlie the AAM-T2DM association. Among them, FN3KRP rs1046896 (cFDR = 6.84 × 10−49), CDKAL1 rs2206734 (cFDR = 6.48 × 10−10), B3GNTL1 rs58431774 (cFDR = 2.95 × 10−10), G6PC2 rs1402837 (cFDR = 1.82 × 10−8), and KCNQ1 rs60808706 (cFDR = 9.49 × 10−8) were highlighted for their significant genetic enrichment. The protein–protein interaction analysis revealed a significantly enriched network among novel discovered genes that were mostly found to be involved in the insulin and glucagon signaling pathways. Conclusions: Our study highlights potential pleiotropic effects across AAM and T2DM. This may shed light on identifying the genetic causes of T2DM. Full article
(This article belongs to the Special Issue Genetics, Obesity, Diabetes and Metabolic Syndrome)
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9 pages, 2496 KB  
Communication
Recessive COL17A1 Mutations and a Dominant LAMB3 Mutation Cause Hypoplastic Amelogenesis Imperfecta
by Youn Jung Kim, Yejin Lee, Wonseon Chae and Jung-Wook Kim
J. Pers. Med. 2023, 13(10), 1494; https://doi.org/10.3390/jpm13101494 - 14 Oct 2023
Cited by 2 | Viewed by 1846
Abstract
Hereditary conditions that affect tooth enamel in quantity and/or quality are called amelogenesis imperfecta (AI). AI can occur as an isolated condition or as a symptom of a syndrome. An OMIM search with the term “AI” yielded 79 result entries. Mutations in the [...] Read more.
Hereditary conditions that affect tooth enamel in quantity and/or quality are called amelogenesis imperfecta (AI). AI can occur as an isolated condition or as a symptom of a syndrome. An OMIM search with the term “AI” yielded 79 result entries. Mutations in the same gene cause syndromic or non-syndromic AI, depending on the nature of the mutations. In this study, we recruited two AI families and performed mutational analysis using whole-exome sequencing. The proband of family 1, with hypoplastic pitted AI and mild localized atopic dermatitis, had compound heterozygous COL17A1 mutations (paternal NM_000494.4: c.3598G>T, p.Asp1200Tyr and maternal c.1700G>A, p.Gly567Glu). The proband of family 2, with hypoplastic pitted AI and Jervell and Lange-Nielsen syndrome, had a recurrent LAMB3 mutation (NM_000228.3: c.3463_3475del, p.(Glu1155Thrfs*51)) in addition to compound heterozygous mutations in the KCNQ1 gene. Full article
(This article belongs to the Special Issue Precision Medicine for Oral Diseases)
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17 pages, 2372 KB  
Article
Saudi Community-Based Screening Study on Genetic Variants in β-Cell Dysfunction and Its Role in Women with Gestational Diabetes Mellitus
by Amal F. Alshammary, Malak Mohammed Al-Hakeem and Imran Ali Khan
Genes 2023, 14(4), 924; https://doi.org/10.3390/genes14040924 - 16 Apr 2023
Cited by 12 | Viewed by 2850
Abstract
Background: Diabetes (hyperglycemia) is defined as a multifactorial metabolic disorder in which insulin resistance and defects in pancreatic β-cell dysfunction are two major pathophysiologic abnormalities that underpin towards gestational diabetes mellitus (GDM). TCF7L2, KCNQ1, and KCNJ11 genes are connected to the [...] Read more.
Background: Diabetes (hyperglycemia) is defined as a multifactorial metabolic disorder in which insulin resistance and defects in pancreatic β-cell dysfunction are two major pathophysiologic abnormalities that underpin towards gestational diabetes mellitus (GDM). TCF7L2, KCNQ1, and KCNJ11 genes are connected to the mechanism of β-cell dysfunction. The purpose of this study was to investigate the genes associated with β-cell dysfunction and their genetic roles in the rs7903146, rs2237892, and rs5219 variants in Saudi women diagnosed with type 2 diabetes mellitus and GDM. Materials and Methods: In this case-control study, 100 women with GDM and 100 healthy volunteers (non-GDM) were recruited. Genotyping was performed using polymerase chain reaction (PCR), followed by restriction fragment length analysis. Validation was performed using Sanger sequencing. Statistical analyses were performed using multiple software packages. Results: Clinical studies showed a β-cell dysfunction positive association in women with GDM when compared to non-GDM women (p < 0.05). Both rs7903146 (CT vs. CC: OR-2.12 [95%CI: 1.13–3.96]; p = 0.01 & T vs. C: (OR-2.03 [95%CI: 1.32–3.11]; p = 0.001) and rs5219 SNPs (AG vs. AA: OR-3.37 [95%CI: 1.63–6.95]; p = 0.0006 & G vs. A: OR-3.03 [95%CI: 1.66–5.52]; p = 0.0001) showed a positive association with genotype and allele frequencies in women with GDM. ANOVA analysis confirmed that weight (p = 0.02), BMI (p = 0.01), and PPBG (p = 0.003) were associated with rs7903146 and BMI (p = 0.03) was associated with rs2237892 SNPs. Conclusions: This study confirms that the SNPs rs7903146 (TCF7L2) and rs5219 (KCNJ11) are strongly associated with GDM in the Saudi population. Future studies should address the limitations of this study. Full article
(This article belongs to the Section Human Genomics and Genetic Diseases)
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11 pages, 18339 KB  
Case Report
Eosinophilic Infiltration of the Sino-Atrial Node in Sudden Cardiac Death Caused by Long QT Syndrome
by Simone Grassi, Oscar Campuzano, Mònica Coll, Francesca Cazzato, Anna Iglesias, Francesco Ausania, Francesca Scarnicci, Georgia Sarquella-Brugada, Josep Brugada, Vincenzo Arena, Antonio Oliva and Ramon Brugada
Int. J. Mol. Sci. 2022, 23(19), 11666; https://doi.org/10.3390/ijms231911666 - 1 Oct 2022
Cited by 1 | Viewed by 2786
Abstract
Sudden death is defined as the unexpected death of a healthy person that occurs within the first hour of the onset of symptoms or within 24 h of the victim being last seen alive. In some of these cases, rare deleterious variants of [...] Read more.
Sudden death is defined as the unexpected death of a healthy person that occurs within the first hour of the onset of symptoms or within 24 h of the victim being last seen alive. In some of these cases, rare deleterious variants of genes associated with inherited cardiac disorders can provide a highly probable explanation for the fatal event. We report the case of a 21-year-old obese woman who lost consciousness suddenly in a public place and was pronounced dead after hospital admission. Clinical autopsy showed an inconclusive gross examination, while in the histopathological analysis an eosinophilic inflammatory focus and interstitial fibrosis in the sino-atrial node were found. Molecular autopsy revealed an intronic variant in the KCNQ1 gene (c.683 + 5G > A), classified as likely pathogenic for long QT syndrome according to the guidelines provided by the American College of Medical Genetics and Genomics. Therefore, there were many anomalies that could have played a role in the causation of the sudden death, such as the extreme obesity, the cardiac anomalies and the KNCQ1 variant. This case depicts the difficult interpretation of rare cardiac structural abnormalities in subjects carrying rare variants responsible for inherited arrhythmic disorders and the challenge for the forensic pathologist to make causal inferences in the determinism of the unexpected decease. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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17 pages, 5520 KB  
Article
In Vitro Drug Screening Using iPSC-Derived Cardiomyocytes of a Long QT-Syndrome Patient Carrying KCNQ1 & TRPM4 Dual Mutation: An Experimental Personalized Treatment
by Feifei Wang, Yafan Han, Wanyue Sang, Lu Wang, Xiaoyan Liang, Liang Wang, Qiang Xing, Yankai Guo, Jianghua Zhang, Ling Zhang, Tuerhong Zukela, Jiasuoer Xiaokereti, Yanmei Lu, Xianhui Zhou, Baopeng Tang and Yaodong Li
Cells 2022, 11(16), 2495; https://doi.org/10.3390/cells11162495 - 11 Aug 2022
Cited by 9 | Viewed by 3414
Abstract
Congenital long QT syndrome is a type of inherited cardiovascular disorder characterized by prolonged QT interval. Patient often suffer from syncopal episodes, electrocardiographic abnormalities and life-threatening arrhythmia. Given the complexity of the root cause of the disease, a combination of clinical diagnosis and [...] Read more.
Congenital long QT syndrome is a type of inherited cardiovascular disorder characterized by prolonged QT interval. Patient often suffer from syncopal episodes, electrocardiographic abnormalities and life-threatening arrhythmia. Given the complexity of the root cause of the disease, a combination of clinical diagnosis and drug screening using patient-derived cardiomyocytes represents a more effective way to identify potential cures. We identified a long QT syndrome patient carrying a heterozygous KCNQ1 c.656G>A mutation and a heterozygous TRPM4 c.479C>T mutation. Implantation of implantable cardioverter defibrillator in combination with conventional medication demonstrated limited success in ameliorating long-QT-syndrome-related symptoms. Frequent defibrillator discharge also caused deterioration of patient quality of life. Aiming to identify better therapeutic agents and treatment strategy, we established a patient-specific iPSC line carrying the dual mutations and differentiated these patient-specific iPSCs into cardiomyocytes. We discovered that both verapamil and lidocaine substantially shortened the QT interval of the long QT syndrome patient-specific cardiomyocytes. Verapamil treatment was successful in reducing defibrillator discharge frequency of the KCNQ1/TRPM4 dual mutation patient. These results suggested that verapamil and lidocaine could be alternative therapeutic agents for long QT syndrome patients that do not respond well to conventional treatments. In conclusion, our approach indicated the usefulness of the in vitro disease model based on patient-specific iPSCs in identifying pharmacological mechanisms and drug screening. The long QT patient-specific iPSC line carrying KCNQ1/TRPM4 dual mutations also represents a tool for further understanding long QT syndrome pathogenesis. Full article
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14 pages, 2995 KB  
Article
Disruption of a Conservative Motif in the C-Terminal Loop of the KCNQ1 Channel Causes LQT Syndrome
by Maria Karlova, Denis V. Abramochkin, Ksenia B. Pustovit, Tatiana Nesterova, Valery Novoseletsky, Gildas Loussouarn, Elena Zaklyazminskaya and Olga S. Sokolova
Int. J. Mol. Sci. 2022, 23(14), 7953; https://doi.org/10.3390/ijms23147953 - 19 Jul 2022
Cited by 5 | Viewed by 3587
Abstract
We identified a single nucleotide variation (SNV) (c.1264A > G) in the KCNQ1 gene in a 5-year-old boy who presented with a prolonged QT interval. His elder brother and mother, but not sister and father, also had this mutation. This missense mutation leads [...] Read more.
We identified a single nucleotide variation (SNV) (c.1264A > G) in the KCNQ1 gene in a 5-year-old boy who presented with a prolonged QT interval. His elder brother and mother, but not sister and father, also had this mutation. This missense mutation leads to a p.Lys422Glu (K422E) substitution in the Kv7.1 protein that has never been mentioned before. We inserted this substitution in an expression plasmid containing Kv7.1 cDNA and studied the electrophysiological characteristics of the mutated channel expressed in CHO-K1, using the whole-cell configuration of the patch-clamp technique. Expression of the mutant Kv7.1 channel in both homo- and heterozygous conditions in the presence of auxiliary subunit KCNE1 results in a significant decrease in tail current densities compared to the expression of wild-type (WT) Kv7.1 and KCNE1. This study also indicates that K422E point mutation causes a dominant negative effect. The mutation was not associated with a trafficking defect; the mutant channel protein was confirmed to localize at the cell membrane. This mutation disrupts the poly-Lys strip in the proximal part of the highly conserved cytoplasmic A–B linker of Kv7.1 that was not shown before to be crucial for channel functioning. Full article
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7 pages, 217 KB  
Case Report
Autism Spectrum Disorder and a De Novo Kcnq2 Gene Mutation: A Case Report
by Martina Siracusano, Claudia Marcovecchio, Assia Riccioni, Caterina Dante and Luigi Mazzone
Pediatr. Rep. 2022, 14(2), 200-206; https://doi.org/10.3390/pediatric14020027 - 24 Apr 2022
Cited by 3 | Viewed by 3465
Abstract
The KCNQ2 gene, encoding for the Kv7.2 subunits of the Kv7 voltage potassium channel, is involved in the modulation of neuronal excitability and plays a crucial role in brain morphogenesis and maturation during embryonic life. De novo heterozygous mutations [...] Read more.
The KCNQ2 gene, encoding for the Kv7.2 subunits of the Kv7 voltage potassium channel, is involved in the modulation of neuronal excitability and plays a crucial role in brain morphogenesis and maturation during embryonic life. De novo heterozygous mutations in KCNQ2 genes are associated with early-onset epileptic encephalopathy and neurodevelopmental disorders including developmental delay and intellectual disability. However, little is known about the socio-communicative phenotype of children affected by the KCNQ2 mutation, and a detailed behavioral characterization focused on autistic symptoms has not yet been conducted. This case report describes the clinical behavioral phenotype of a 6-year-old boy carrying a de novo heterozygous KCNQ2 mutation, affected by early-onset seizures and autism spectrum disorder (ASD). We performed a neuropsychiatric assessment of cognitive, adaptive, socio-communicative and autistic symptoms through the administration of standardized tools. The main contribution of this case report is to provide a detailed developmental and behavioral characterization focused on ASD symptoms in a child with [c.812 G > A; p. (Gly271Asp)]mutation in the KCNQ2 gene. Full article
9 pages, 3111 KB  
Brief Report
Identification and Computational Analysis of Rare Variants of Known Hearing Loss Genes Present in Five Deaf Members of a Pakistani Kindred
by Irum Badshah Saleem, Muhammad Shareef Masoud, Muhammad Qasim, Muhammad Ali and Zubair M. Ahmed
Genes 2021, 12(12), 1940; https://doi.org/10.3390/genes12121940 - 30 Nov 2021
Cited by 3 | Viewed by 3012
Abstract
Hearing loss (HL) is the most common neurosensory defect in humans that affects the normal communication. Disease is clinically and genetically heterogeneous, rendering challenges for the molecular diagnosis of affected subjects. This study highlights the phenotypic and genetic complexity of inherited HL in [...] Read more.
Hearing loss (HL) is the most common neurosensory defect in humans that affects the normal communication. Disease is clinically and genetically heterogeneous, rendering challenges for the molecular diagnosis of affected subjects. This study highlights the phenotypic and genetic complexity of inherited HL in a large consanguineous Pakistan kindred. Audiological evaluation of all affected individuals revealed varying degree of mild to profound sensorineural HL. Whole exome (WES) of four family members followed by Sanger sequencing revealed candidate disease-associated variants in five known deafness genes: GJB2 (c.231G>A; p.(Trp77 *)), SLC26A4 (c.1337A>G; p.(Gln446Arg)), CDH23 (c.2789C>T; p.(Pro930Leu)), KCNQ4 (c.1672G>A; p.(Val558Met)) and MPDZ (c.4124T>C; p.(Val1375Ala)). All identified variants replaced evolutionary conserved residues, were either absent or had low frequencies in the control databases. Our in silico and 3-Dimensional (3D) protein topology analyses support the damaging impact of identified variants on the encoded proteins. However, except for the previously established “pathogenic” and “likely pathogenic” categories for the c.231G>A (p.(Trp77 *)) allele of GJB2 and c.1377A>G (p.(Gln446Arg)) of SLC26A4, respectively, all the remaining identified variants were classified as “uncertain significance” based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) variant pathogenicity guidelines. Our study highlights the complexity of genetic traits in consanguineous families, and the need of combining the functional studies even with the comprehensive profiling of multiple family members to improve the genetic diagnosis in complex inbred families. Full article
(This article belongs to the Special Issue Genetics and Epigenetics of Hearing Loss)
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12 pages, 1163 KB  
Article
A KCNQ4 c.546C>G Genetic Variant Associated with Late Onset Non-Syndromic Hearing Loss in a Taiwanese Population
by Ting-Ting Yen, I-Chieh Chen, Men-Wei Hua, Chia-Yi Wei, Kai-Hsiang Shih, Jui-Lin Li, Ching-Heng Lin, Tzu-Hung Hsiao, Yi-Ming Chen and Rong-San Jiang
Genes 2021, 12(11), 1711; https://doi.org/10.3390/genes12111711 - 27 Oct 2021
Cited by 9 | Viewed by 3108
Abstract
Clinical presentation is heterogeneous for autosomal dominant nonsyndromic hearing loss (ADNSHL). Variants of KCNQ4 gene is a common genetic factor of ADNSHL. Few studies have investigated the association between hearing impairment and the variant c.546C>G of KCNQ4. Here, we investigated the phenotype [...] Read more.
Clinical presentation is heterogeneous for autosomal dominant nonsyndromic hearing loss (ADNSHL). Variants of KCNQ4 gene is a common genetic factor of ADNSHL. Few studies have investigated the association between hearing impairment and the variant c.546C>G of KCNQ4. Here, we investigated the phenotype and clinical manifestations of the KCNQ4 variant. Study subjects were selected from the participants of the Taiwan Precision Medicine Initiative. In total, we enrolled 12 individuals with KCNQ4 c.546C>G carriers and 107 non-carriers, and performed pure tone audiometry (PTA) test and phenome-wide association (PheWAS) analysis for the patients. We found that c.546C>G variant was related to an increased risk of hearing loss. All patients with c.546C>G variant were aged >65 years and had sensorineural and high frequency hearing loss. Of these patients, a third (66.7%) showed moderate and progressive hearing loss, 41.7% complained of tinnitus and 16.7% complained of vertigo. Additionally, we found a significant association between KCNQ4 c.546C>G variant, aortic aneurysm, fracture of lower limb and polyneuropathy in diabetes. KCNQ4 c.546C>G is likely a potentially pathogenic variant of ADNSHL in the elderly population. Genetic counseling, annual audiogram and early assistive listening device intervention are highly recommended to prevent profound hearing impairment in this patient group. Full article
(This article belongs to the Section Human Genomics and Genetic Diseases)
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Article
Epileptic Encephalopathy In A Patient With A Novel Variant In The Kv7.2 S2 Transmembrane Segment: Clinical, Genetic, and Functional Features
by Maria Virginia Soldovieri, Paolo Ambrosino, Ilaria Mosca, Francesco Miceli, Cristina Franco, Lorella Maria Teresa Canzoniero, Beth Kline-Fath, Edward C. Cooper, Charu Venkatesan and Maurizio Taglialatela
Int. J. Mol. Sci. 2019, 20(14), 3382; https://doi.org/10.3390/ijms20143382 - 10 Jul 2019
Cited by 17 | Viewed by 4454
Abstract
Kv7.2 subunits encoded by the KCNQ2 gene provide a major contribution to the M-current (IKM), a voltage-gated K+ current crucially involved in the regulation of neuronal excitability. Heterozygous missense variants in Kv7.2 are responsible for epileptic diseases characterized by highly [...] Read more.
Kv7.2 subunits encoded by the KCNQ2 gene provide a major contribution to the M-current (IKM), a voltage-gated K+ current crucially involved in the regulation of neuronal excitability. Heterozygous missense variants in Kv7.2 are responsible for epileptic diseases characterized by highly heterogeneous genetic transmission and clinical severity, ranging from autosomal-dominant Benign Familial Neonatal Seizures (BFNS) to sporadic cases of severe epileptic and developmental encephalopathy (DEE). Here, we describe a patient with neonatal onset DEE, carrying a previously undescribed heterozygous KCNQ2 c.418G > C, p.Glu140Gln (E140Q) variant. Patch-clamp recordings in CHO cells expressing the E140Q mutation reveal dramatic loss of function (LoF) effects. Multistate structural modelling suggested that the E140Q substitution impeded an intrasubunit electrostatic interaction occurring between the E140 side chain in S2 and the arginine at position 210 in S4 (R210); this interaction is critically involved in stabilizing the activated configuration of the voltage-sensing domain (VSD) of Kv7.2. Functional results from coupled charge reversal or disulfide trapping experiments supported such a hypothesis. Finally, retigabine restored mutation-induced functional changes, reinforcing the rationale for the clinical use of Kv7 activators as personalized therapy for DEE-affected patients carrying Kv7.2 LoF mutations. Full article
(This article belongs to the Special Issue Epilepsy: From Molecular Mechanisms to Targeted Therapies)
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