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1.
Brief Bioinform ; 25(6)2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39311700

RESUMO

De novo mutations in the synaptic GTPase activating protein (SynGAP) are associated with neurological disorders like intellectual disability, epilepsy, and autism. SynGAP is also implicated in Alzheimer's disease and cancer. Although pathogenic variants are highly penetrant in neurodevelopmental conditions, a substantial number of them are caused by missense mutations that are difficult to diagnose. Hence, in silico mutagenesis was performed for probing the missense effects within the N-terminal region of SynGAP structure. Through extensive molecular dynamics simulations, encompassing three 150-ns replicates for 211 variants, the impact of missense mutations on the protein fold was assessed. The effect of the mutations on the folding stability was also quantitatively assessed using free energy calculations. The mutations were categorized as potentially pathogenic or benign based on their structural impacts. Finally, the study introduces wild-type-SynGAP in complex with RasGTPase at the inner membrane, while considering the potential effects of mutations on these key interactions. This study provides structural perspective to the clinical assessment of SynGAP missense variants and lays the foundation for future structure-based drug discovery.


Assuntos
Simulação de Dinâmica Molecular , Mutação de Sentido Incorreto , Proteínas Ativadoras de ras GTPase , Humanos , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/química , Proteínas Ativadoras de ras GTPase/metabolismo , Dobramento de Proteína , Relação Estrutura-Atividade
2.
Brief Bioinform ; 25(1)2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-38018912

RESUMO

Dysfunctions caused by missense mutations in the tumour suppressor p53 have been extensively shown to be a leading driver of many cancers. Unfortunately, it is time-consuming and labour-intensive to experimentally elucidate the effects of all possible missense variants. Recent works presented a comprehensive dataset and machine learning model to predict the functional outcome of mutations in p53. Despite the well-established dataset and precise predictions, this tool was trained on a complicated model with limited predictions on p53 mutations. In this work, we first used computational biophysical tools to investigate the functional consequences of missense mutations in p53, informing a bias of deleterious mutations with destabilizing effects. Combining these insights with experimental assays, we present two interpretable machine learning models leveraging both experimental assays and in silico biophysical measurements to accurately predict the functional consequences on p53 and validate their robustness on clinical data. Our final model based on nine features obtained comparable predictive performance with the state-of-the-art p53 specific method and outperformed other generalized, widely used predictors. Interpreting our models revealed that information on residue p53 activity, polar atom distances and changes in p53 stability were instrumental in the decisions, consistent with a bias of the properties of deleterious mutations. Our predictions have been computed for all possible missense mutations in p53, offering clinical diagnostic utility, which is crucial for patient monitoring and the development of personalized cancer treatment.


Assuntos
Mutação de Sentido Incorreto , Neoplasias , Humanos , Proteína Supressora de Tumor p53/genética , Mutação , Neoplasias/genética , Aprendizado de Máquina
3.
Brief Bioinform ; 24(4)2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37332013

RESUMO

We report the structure-based pathogenicity relationship identifier (SPRI), a novel computational tool for accurate evaluation of pathological effects of missense single mutations and prediction of higher-order spatially organized units of mutational clusters. SPRI can effectively extract properties determining pathogenicity encoded in protein structures, and can identify deleterious missense mutations of germ line origin associated with Mendelian diseases, as well as mutations of somatic origin associated with cancer drivers. It compares favorably to other methods in predicting deleterious mutations. Furthermore, SPRI can discover spatially organized pathogenic higher-order spatial clusters (patHOS) of deleterious mutations, including those of low recurrence, and can be used for discovery of candidate cancer driver genes and driver mutations. We further demonstrate that SPRI can take advantage of AlphaFold2 predicted structures and can be deployed for saturation mutation analysis of the whole human proteome.


Assuntos
Mutação de Sentido Incorreto , Neoplasias , Humanos , Virulência , Mutação , Neoplasias/genética , Biologia Computacional/métodos
4.
Hum Genomics ; 18(1): 6, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38287462

RESUMO

BACKGROUND: Congenital heart defects (CHDs) are the heart structural malformations present at birth. Septal defects account for 40% of CHD, including atrial, ventricular and atrioventricular septal defects. In Pakistan, the prevalence of CHD is 3.4 in 1000, and a study estimated that 60,000 babies are born with CHD annually. Methylenetetrahydrofolate reductase (MTHFR), a chief enzyme, involved in the folate metabolism. The missense mutation, C677T (rs1801133), exists in MTHFR gene, results in a MTHFR thermolabile variant having low enzymatic activity. The study is aim to identify the MTHFR C677T variant association with septal defects. METHODS: Samples of 194 CHD patients (age [Formula: see text]= 5.8 ± 5.1) and 50 normal echo controls (age [Formula: see text]= 6.0 ± 4.9), confirmed by pediatric consultant, were collected. Extracted DNA, quantified by agarose gel electrophoresis and nanodrop, was screened for SNP by high-resolution melting (HRM). Further, HRM results were confirmed using restriction analysis and sequencing. HRM was simply and precisely genotyped the samples within 3 h at low cost. RESULTS: Genotypic data suggested that heterozygous mutant (CT) was frequent in congenital septal defect patients (0.26) which was higher than controls (0.143), p > 0.05. Mutant (TT) genotype was not found in this study. CONCLUSIONS: rs1801133 has lack of significant association with congenital septal defects. The absence of TT genotype in this study suggesting the role of natural selection in targeted population. HRM is an easy, fast and next generation of PCR, which may be used for applied genomics.


Assuntos
Cardiopatias Congênitas , Metilenotetra-Hidrofolato Redutase (NADPH2) , Recém-Nascido , Humanos , Criança , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Paquistão/epidemiologia , Cardiopatias Congênitas/genética , Genótipo , Reação em Cadeia da Polimerase , Predisposição Genética para Doença , Estudos de Casos e Controles
5.
Hum Genomics ; 18(1): 22, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38424652

RESUMO

BACKGROUND: To report newly found TSPAN12 mutations with a unique form of familial exudative vitreoretinopathy (FEVR) and find out the possible mechanism of a repeated novel intronic variant in TSPAN12 led to FEVR. RESULTS: Nine TSPAN12 mutations with a unique form of FEVR were detected by panel-based NGS. MINI-Gene assay showed two splicing modes of mRNA that process two different bands A and B, and mutant-type shows replacement with the splicing mode of Exon11 hopping. Construction of wild-type and mutant TSPAN12 vector showed the appearance of premature termination codons (PTC). In vitro expression detection showed significant down-regulated expression level of TSPAN12 mRNAs and proteins in cells transfected with mutant vectors compared with in wild-type group. On the contrary, translation inhibitor CHX and small interfering RNA of UPF1 (si-UPF1) significantly increased mRNA or protein expression of TSPAN12 in cells transfected with the mutant vectors. CONCLUSIONS: Nine mutations in TSPAN12 gene are reported in 9 FEVR patients with a unique series of ocular abnormalities. The three novel TSPAN12 mutations trigger NMD would cause the decrease of TSPAN12 proteins that participate in biosynthesis and assembly of microfibers, which might lead to FEVR, and suggest that intronic sequence analysis might be a vital tool for genetic counseling and prenatal diagnoses.


Assuntos
Códon sem Sentido , Tetraspaninas , Humanos , Vitreorretinopatias Exsudativas Familiares/genética , Vitreorretinopatias Exsudativas Familiares/diagnóstico , Tetraspaninas/genética , Tetraspaninas/metabolismo , Linhagem , Mutação , Análise Mutacional de DNA , Transativadores/genética , RNA Helicases/genética
6.
Methods ; 222: 122-132, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38185227

RESUMO

Predicting the functionality of missense mutations is extremely difficult. Large-scale genomic screens are commonly performed to identify mutational correlates or drivers of disease and treatment resistance, but interpretation of how these mutations impact protein function is limited. One such consequence of mutations to a protein is to impact its ability to bind and interact with partners or small molecules such as ATP, thereby modulating its function. Multiple methods exist for predicting the impact of a single mutation on protein-protein binding energy, but it is difficult in the context of a genomic screen to understand if these mutations with large impacts on binding are more common than statistically expected. We present a methodology for taking mutational data from large-scale genomic screens and generating functional and statistical insights into their role in the binding of proteins both with each other and their small molecule ligands. This allows a quantitative and statistical analysis to determine whether mutations impacting protein binding or ligand interactions are occurring more or less frequently than expected by chance. We achieve this by calculating the potential impact of any possible mutation and comparing an expected distribution to the observed mutations. This method is applied to examples demonstrating its ability to interpret mutations involved in protein-protein binding, protein-DNA interactions, and the evolution of therapeutic resistance.


Assuntos
Genômica , Proteínas , Ligação Proteica , Mutação , Sítios de Ligação , Proteínas/genética
7.
J Cell Biochem ; 125(1): 89-99, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38047473

RESUMO

Checkpoint kinases Chk1, Chk2, Wee1 are playing a key role in DNA damage response and genomic integrity. Cancer-associated mutations identified in human Chk1, Chk2, and Wee1 were retrieved to understand the function associated with the mutation and also alterations in the folding pattern. Therefore, an attempt has been made to identify deleterious effect of variants using in silico and structure-based approach. Variants of uncertain significance for Chk1, Chk2, and Wee1 were retrieved from different databases and four prediction servers were employed to predict pathogenicity of mutations. Further, Interpro, I-Mutant 3.0, Consurf, TM-align, and have (y)our protein explained were used for comprehensive study of the deleterious effects of variants. The sequences of Chk1, Chk2, and Wee1 were analyzed using Clustal Omega, and the three-dimensional structures of the proteins were aligned using TM-align. The molecular dynamics simulations were performed to explore the differences in folding pattern between Chk1, Chk2, Wee1 wild-type, and mutant protein and also to evaluate the structural integrity. Thirty-six variants in Chk1, 250 Variants in Chk2, and 29 in Wee1 were categorized as pathogenic using in silico prediction tools. Furthermore, 25 mutations in Chk1, 189 in Chk2, and 14 in Wee1 were highly conserved, possessing deleterious effect and also influencing the protein structure and function. These identified mutations may provide underlying genetic intricacies to serve as potential targets for therapeutic inventions and clinical management.


Assuntos
Neoplasias , Proteínas Quinases , Humanos , Proteínas Quinases/metabolismo , Quinase 1 do Ponto de Checagem/genética , Mutação , Quinase do Ponto de Checagem 2/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo
8.
Mol Genet Genomics ; 299(1): 81, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39172257

RESUMO

Autosomal-recessive cutis laxa type 2 (ARCL2) is a rare genetic disorder caused by pyrroline-5-carboxylate reductase 1 (PYCR1) mutations and characterized by loose and sagging skin, typical facial features, intrauterine growth retardation, and developmental delay. To study the effect of PYCR1 mutations on protein function and clinical features, we identified a homozygous missense mutation c.559G > A (p.Ala187Thr) in PYCR1 in a Chinese child with typical clinical features, especially severe developmental delays. The three-dimensional (3D) model showed the modification of the hydrogen bonds produce a misfolding in the mutant PYCR1 protein. Mutagenesis and enzyme assay study revealed decreased activity of the mutant protein in vitro, indicating that this mutation impairs PYCR1 function. Our findings confirmed abnormal enzymatic activity and neurodevelopmental trajectory of this PYCR1 mutation.


Assuntos
Cútis Laxa , Mutação de Sentido Incorreto , Pirrolina Carboxilato Redutases , delta-1-Pirrolina-5-Carboxilato Redutase , Humanos , Cútis Laxa/genética , Cútis Laxa/patologia , Pirrolina Carboxilato Redutases/genética , Pirrolina Carboxilato Redutases/metabolismo , Masculino , Feminino , Pré-Escolar , Modelos Moleculares , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Homozigoto , Genes Recessivos , Mutação
9.
Clin Genet ; 105(5): 488-498, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38193334

RESUMO

ALDH1L2, a mitochondrial enzyme in folate metabolism, converts 10-formyl-THF (10-formyltetrahydrofolate) to THF (tetrahydrofolate) and CO2. At the cellular level, deficiency of this NADP+-dependent reaction results in marked reduction in NADPH/NADP+ ratio and reduced mitochondrial ATP. Thus far, a single patient with biallelic ALDH1L2 variants and the phenotype of a neurodevelopmental disorder has been reported. Here, we describe another patient with a neurodevelopmental disorder associated with a novel homozygous missense variant in ALDH1L2, Pro133His. The variant caused marked reduction in the ALDH1L2 enzyme activity in skin fibroblasts derived from the patient as probed by 10-FDDF, a stable synthetic analog of 10-formyl-THF. Additional associated abnormalities in these fibroblasts include reduced NADPH/NADP+ ratio and pool of mitochondrial ATP, upregulated autophagy and dramatically altered metabolomic profile. Overall, our study further supports a link between ALDH1L2 deficiency and abnormal neurodevelopment in humans.


Assuntos
Oxirredutases atuantes sobre Doadores de Grupo CH-NH , Humanos , Trifosfato de Adenosina , NADP/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Fenótipo
10.
Clin Genet ; 106(5): 638-643, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39003656

RESUMO

Intellectual disability (ID) is a kind of nervous developmental disorder and affects more than 1% of people worldwide. SLC45A1 as a transmembrane protein is implicated in the regulation of glucose homoeostasis. Through trio-based exome sequencing, the missense mutations of SLC45A1 c.103G>A (p.V35M) and c.1211T>G (p.F404C) were identified in the proband with syndromic ID. The distribution, expression and activity of SLC45A1 wild-type (WT) and variants were assayed in transfected COS7 cells. In SLC45A1 variants, the hydrogen bonds surrounding the 35th and 404th amino acid were changed, location on the cytomembrane was failed, their activity to transport glucose was also significantly decreased to contrast with SLC45A1-WT. No difference was observed at the mRNA and protein level. In conclusion, the compound heterozygous variants of SLC45A1 might be the genetic etiology for syndromic ID. These novel mutations probably attenuated its activity to transport glucose by the alteration of tertiary structure and failure of intracellular location.


Assuntos
Heterozigoto , Deficiência Intelectual , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Células COS , Chlorocebus aethiops , Masculino , Animais , Sequenciamento do Exoma , Feminino , Mutação de Sentido Incorreto/genética , Predisposição Genética para Doença , Linhagem , Mutação/genética , Glucose/metabolismo
11.
Exp Eye Res ; 248: 110090, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39278391

RESUMO

Several unique mutations of ADAMTSL4 leading to congenital ectopia lentis (CEL) have been previously reported by our team. The purpose of this study is to find out the possible mechanism of a recurrent novel intronic variant in ADAMTSL4 led to CEL. Twelve novel ADAMTSL4 mutations with a unique form congenital ectopic lentis were detected previously by panel-based NGS. Genetic analysis verified a novel heterozygous ADAMTSL4 variation c.2177+4A > G on Intron 11 in two unrelated patients with iris and lens abnormalities. MINI-Gene assay showed two splicing modes of mRNA that process two different bands A and B, and mutant-type shows replacement with the splicing mode of Exon 11 skipping. Construction of wild-type and mutant ADAMTSL4 vector showed the appearance of premature termination codons (PTC). In vitro expression detection showed significant down-regulated expression level of ADAMTSL4 mRNAs and proteins in cells transfected with mutant vectors compared with in wild-type group. On the contrary, translation inhibitor CHX and small interfering RNA of UPF1 (si-UPF1) significantly increased mRNA or protein expression of ADAMTSL4 in cells transfected with the mutant vectors. 12 novel mutations in ADAMTSL4 gene have been previously reported by our team in 6 CEL patients with a unique series of ocular abnormalities. The recurrent novel ADAMTSL4 mutation c.2177+4A > G triggering the splicing mode of Exon 11 skipping and NMD would cause the decrease of ADAMTSL4 proteins that participate in biosynthesis and assembly of microfibers, which might lead to CEL, and suggest that sequencing of certain intronic splicing varition might be a vital tool for genetic counseling and prenatal diagnoses.

12.
Cell Commun Signal ; 22(1): 401, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39148095

RESUMO

TP53 mutation (TP53-mut) correlates with inferior survival in many cancers, whereas its prognostic role in diffuse large B-cell lymphoma (DLBCL) is still in controversy. Therefore, more precise risk stratification needs to be further explored for TP53-mut DLBCL patients. A set of 2637 DLBCL cases from multiple cohorts, was enrolled in our analysis. Among the 2637 DLBCL patients, 14.0% patients (370/2637) had TP53-mut. Since missense mutations account for the vast majority of TP53-mut DLBCL patients, and most non-missense mutations affect the function of the P53 protein, leading to worse survival rates, we distinguished patients with missense mutations. A TP53 missense mutation risk model was constructed based on a 150-combination machine learning computational framework, demonstrating excellent performance in predicting prognosis. Further analysis revealed that patients with high-risk missense mutations are significantly associated with early progression and exhibit dysregulation of multiple immune and metabolic pathways at the transcriptional level. Additionally, the high-risk group showed an absolutely suppressed immune microenvironment. To stratify the entire cohort of TP53-mut DLBCL, we combined clinical characteristics and ultimately constructed the TP53 Prognostic Index (TP53PI) model. In summary, we identified the truly high-risk TP53-mut DLBCL patients and explained this difference at the mutation and transcriptional levels.


Assuntos
Linfoma Difuso de Grandes Células B , Proteína Supressora de Tumor p53 , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Humanos , Proteína Supressora de Tumor p53/genética , Prognóstico , Mutação de Sentido Incorreto/genética , Mutação/genética , Microambiente Tumoral/genética , Masculino , Feminino , Fatores de Risco , Pessoa de Meia-Idade
13.
Neurol Sci ; 45(9): 4597-4600, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38771523

RESUMO

BACKGROUND: Neuronal ceroid lipofuscinoses are a genetically heterogeneous group of inherited lysosomal storage disorders. Kufs disease is the predominant form of neuronal ceroid lipofuscinosis in adults, but it's rare and challenging to diagnose. CASE DESCRIPTION: The proband initially presented with cognitive deterioration and parkinsonian traits. At 35, he was admitted to hospital following a tonic-clonic seizure. Brain magnetic resonance imaging showed atrophy of the cerebral cortex and cerebellum, enlarged ventricles, and thinned corpus callosum. The proband's younger brother and sister were also affected, and the clinical phenotype within the family was consistent. Whole-exome Sequencing of the proband revealed a novel homozygous mutation in CLN6 (NM_017882: c.425A > G, p. Tyr142Cys). Co-segregation analysis revealed that two other affected individuals carried a homozygous mutation at the same locus, with both parents exhibiting heterozygous mutations of c.425A > G. CONCLUSION: Our study not only provides insights into the clinical presentation and development of the disease within the affected family but also expanded the mutational and phenotypical spectrum of the CLN6 gene.


Assuntos
Proteínas de Membrana , Lipofuscinoses Ceroides Neuronais , Linhagem , Humanos , Lipofuscinoses Ceroides Neuronais/genética , Lipofuscinoses Ceroides Neuronais/diagnóstico por imagem , Lipofuscinoses Ceroides Neuronais/patologia , Masculino , Proteínas de Membrana/genética , Adulto , Feminino , Homozigoto , Mutação , Fenótipo
14.
Vet Pathol ; : 3009858241283501, 2024 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-39394905

RESUMO

Lissencephaly and cerebellar hypoplasia (LCH) represents a spectrum of congenital developmental malformations of the cerebral cortex and cerebellum, mostly occurring as inherited conditions caused by variants in an increasingly recognized number of genes. LCH has been identified in three Dorset-cross lambs with congenital neurological signs in Australia. Lambs were unable to walk and had reduced vision, and one lamb developed a hypermetric gait and intention tremors. Grossly, the lambs had diffuse pachygyria with reduction in white matter, mild bilateral ventriculomegaly of the lateral ventricles, and a markedly hypoplastic cerebellum. Histologically, there was disorganization of neurons within the cerebral cortex and hippocampus. The cerebellar vermis had disorganized, thin, and hypocellular gray matter with frequent ectopic Purkinje cells, while identifiable folia were largely absent within the hemispheres. Luxol fast blue stain and glial fibrillary acidic protein, neuronal nuclear protein, synaptophysin, and neuron-specific enolase immunohistochemistry confirmed the thickened, disorganized cerebral cortical gray matter and reduced white matter. Within the cerebellum, immunohistochemistry demonstrated marked dysplasia. Whole-genome sequencing analysis and prediction of variant effects identified a missense variant of interest in the candidate gene reelin (RELN; NC_040255.1:g.50288685C>T; NM_001306121.1:c.7088G>A; NP_001293050.1:p.(R2363H)) with a deleterious Sorting Intolerant from Tolerant (SIFT) score. Sanger sequencing identified that the variant segregated with LCH disease in the 3 affected individuals, their sire, and 6 unaffected flock members. The NP_001293050.1: p.(R2363H) substitution is predicted to decrease the stability of the protein (ΔΔG = -1.55 kcal/mol). Pathological and genetic findings are consistent with previously described phenotypes of RELN variants in Churra sheep, dogs, and humans.

15.
Hereditas ; 161(1): 4, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38233949

RESUMO

BACKGROUND: Fibrinogen plays pivotal roles in multiple biological processes. Genetic mutation of the fibrinogen coding genes can result in congenital fibrinogen disorders (CFDs). We identified a novel heterozygous missense mutation, FGG c.1168G > T (NCBI NM_000509.6), and conducted expression studies and functional analyses to explore the influence on fibrinogen synthesis, secretion, and polymerization. METHODS: Coagulation tests were performed on the patients to detect the fibrinogen concentration. Whole-exome sequencing (WES) and Sanger sequencing were employed to detect the novel mutation. Recombinant fibrinogen-producing Chinese hamster ovary (CHO) cell lines were built to examine the recombinant fibrinogen synthesis and secretion by western blotting and enzyme-linked immunosorbent assay (ELISA). The functional analysis of fibrinogen was performed by thrombin-catalyzed fibrin polymerization assay. In silico molecular analyses were carried out to elucidate the potential molecular mechanisms. RESULTS: The clinical manifestations, medical history, and laboratory tests indicated the diagnosis of hypodysfibrinogenemia with bleeding phenotype in two patients. The WES and Sanger sequencing revealed that they shared the same heterozygous missense mutation, FGG c.1168G > T. In the expression studies and functional analysis, the missense mutation impaired the recombinant fibrinogen's synthesis, secretion, and polymerization. Furthermore, the in silico analyses indicated novel mutation led to the hydrogen bond substitution. CONCLUSION: The study highlighted that the novel heterozygous missense mutation, FGG c.1168G > T, would change the protein secondary structure, impair the "A: a" interaction, and consequently deteriorate the fibrinogen synthesis, secretion, and polymerization.


Assuntos
Afibrinogenemia , Fibrinogênio , Mutação de Sentido Incorreto , Animais , Cricetinae , Humanos , Células CHO , Cricetulus , Fibrinogênio/genética , Mutação , Fenótipo
16.
Anim Biotechnol ; 35(1): 2258166, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37729465

RESUMO

In this study, we evaluated the copy number variation in the genomes of two groups of Beichuan-white goat populations with large differences in litter size by FST method, and identified 1739 genes and 485 missense mutations in the genes subject to positive selection. Through functional enrichment, ITGAV, LRP4, CDH23, TPRN, RYR2 and CELSR1 genes, involved in embryonic morphogenesis, were essential for litter size trait, which received intensive attention. In addition, some mutation sites of these genes have been proposed (ITGAV: c.38C > T; TPRN: c.133A > T, c.1192A > G, c.1250A > C; CELSR1: c.7640T > C), whose allele frequencies were significantly changed in the high fecundity goat group. Besides, we found that new mutations at these sites altered the hydrophilicity and 3D structure of the protein. Candidate genes related to litter size in this study and their missense mutation sites were identified. These candidate genes are helpful to understand the genetic mechanism of fecundity in Beichuan white goat, and have important significance for future goat breeding.


Assuntos
Variações do Número de Cópias de DNA , Cabras , Gravidez , Feminino , Animais , Cabras/genética , Variações do Número de Cópias de DNA/genética , Genoma/genética , Mutação/genética , Análise de Sequência de DNA , Tamanho da Ninhada de Vivíparos/genética
17.
Alzheimers Dement ; 20(5): 3629-3648, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38556850

RESUMO

Alzheimer's disease (AD) is a growing problem worldwide. Since ABCA7's identification as a risk gene, it has been extensively researched for its role in the disease. We review its recently characterized structure and what the mechanistic insights teach us about its function. We furthermore provide an overview of identified ABCA7 mutations, their presence in different ancestries and protein domains and how they might cause AD. For ABCA7 PTC variants and a VNTR expansion, haploinsufficiency is proposed as the most likely mode-of-action, although splice events could further influence disease risk. Overall, the need to better understand expression of canonical ABCA7 and its isoforms in disease is indicated. Finally, ABCA7's potential functions in lipid metabolism, phagocytosis, amyloid deposition, and the interplay between these three, is described. To conclude, in this review, we provide a comprehensive overview and discussion about the current knowledge on ABCA7 in AD, and what research questions remain. HIGHLIGHTS: Alzheimer's risk-increasing variants in ABCA7 can be found in up to 7% of AD patients. We review the recently characterized protein structure of ABCA7. We present latest insights in genetics, expression patterns, and functions of ABCA7.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Doença de Alzheimer , Humanos , Doença de Alzheimer/genética , Transportadores de Cassetes de Ligação de ATP/genética , Predisposição Genética para Doença , Mutação , Animais
18.
J Biol Phys ; 50(1): 89-118, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38103157

RESUMO

Acyl-CoA dehydrogenase deficiency (ACAD) is an inherited and potentially fatal disorder with variable clinical symptoms. The relationship between pathogenicity and deleterious point mutations is investigated here in ACAD structures of short (SCAD) and medium-chain (MCAD) types. Structures and dynamic features of native and mutant forms of enzymes models were compared. A total of 2.88 µs molecular dynamics simulations were performed at four different temperatures. Total energy, RMSD, protein ligand interactions and affinity, RMSF measures, secondary structure changes, and important interactions were studied. Mutations in the three main domains of ACADs are pathogenic, while those located at linker turns are not. Mutations affect mostly tetramer formations, secondary structures, and many contacts and interactions. In R206H (MCAD mutant) which is experimentally known to cause a huge turnover decrease, the lack of a single H-bond between substrate and FAD was observed. Secondary structures showed temperature-dependent changes, and SCAD activity was found to be highly correlated to the enzyme helix 3-10 content. Finally, RMSF patterns pointed to one important loop that maintains the substrate close to the active site and is a cause of substrate wobbling upon mutation. Despite similar structure, function, and cellular location, SCAD and MCAD may have different optimum temperatures that are related to the structure taken at that specific temperature. In conclusion, new insight has been provided on the effect of various SCAD and MCAD pathogenic mutations on the structure and dynamical features of the enzymes.


Assuntos
Erros Inatos do Metabolismo Lipídico , Mutação Puntual , Humanos , Virulência , Acil-CoA Desidrogenase/química , Acil-CoA Desidrogenase/genética , Erros Inatos do Metabolismo Lipídico/genética , Estrutura Secundária de Proteína
19.
J Stroke Cerebrovasc Dis ; 33(11): 107816, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38880363

RESUMO

BACKGROUND: Alport syndrome is a genetic disorder caused by mutations in the COL4A5 gene, which encodes type IV collagen α5 chain, leading to chronic nephritis, hearing loss, and ocular abnormalities. Recent reports suggest this genetic mutation may also increase the risk of cerebral aneurysms and fibromuscular dysplasia, indicating a potential association with vascular vulnerability. CASE PRESENTATION: A 66-year-old woman was admitted with recurrent transient weakness of the left hand, which had gradually worsened in duration over three months. Her medical history included chronic nephritis since childhood. Her two sons had end-stage renal disease and hearing loss since their 20s, and her mother also had chronic kidney disease and hearing loss. One son had a history of traumatic subarachnoid hemorrhage, and the other had spinal epidural hematoma. On admission, she had reduced renal function with proteinuria, acute cerebral infarction in the subcortical white matter of the right fronto-parietal and parieto-occipital lobes, and multiple intracranial arterial stenoses (ICAS), including the right middle and right posterior cerebral artery. Vessel wall imaging of the right middle cerebral artery showed a concentric stenotic pattern. Genetic tests identified a pathogenic missense mutation in exon 24 of COL4A5 (exon 24:c.G1700 >C: p.(Gly567Arg)) that was heterozygous for the patient and hemizygous for her son. She was diagnosed with Alport syndrome. CONCLUSION: It is important to consider Alport syndrome as a possible cause of ICAS in patients with a family history of renal failure or hearing loss and to conduct a genetic analysis of type IV collagen genes.

20.
J Pak Med Assoc ; 74(1): 149-152, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38219185

RESUMO

Focal s egmental glomerulosclerosis (F SGS) can cause protei nuria and loss o f k idney fun ction, leading to e ndstage renal di s ease (ESRD). Podocyte injury is the ce ntral pathophysiologi cal mechanis m of hereditary FSGS. Numerous mutations in genes e ncoding or affe cting the transcriptional regulation of podocyte cell compar tments have been detected in patients with genetic FSGS. Herein, we report a rare case of familial FSGS with an autosomal dominant WT1 mutation. A 63-year- old man developed pro teinuri a; his reading showed over 1g prote in/day. A pa thological diagn osis of FSG S was made after rena l biops y. H is elder brother an d a 36-year- old son also had ESRD. Heterozygous variant of WT1 (NM_024426.4) c.1373G>A (p.Arg458Gln ) mi s sense was dete cted in the patient a nd his son , by whole-exome sequen cing. Although genetic screening is not a par t of routine practice, it s hould be per for med in such cases to a id a ppropriate tre atment options sel ecting, revealing extra ren al symptoms, and family planning.


Assuntos
Glomerulosclerose Segmentar e Focal , Falência Renal Crônica , Masculino , Humanos , Idoso , Pessoa de Meia-Idade , Adulto , Glomerulosclerose Segmentar e Focal/genética , Mutação de Sentido Incorreto , Rim , Mutação , Falência Renal Crônica/genética , Proteínas WT1/genética
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