RESUMO
Many dominant genetic disorders result from protein-altering mutations, acting primarily through dominant-negative (DN), gain-of-function (GOF), and loss-of-function (LOF) mechanisms. Deciphering the mechanisms by which dominant diseases exert their effects is often experimentally challenging and resource intensive, but is essential for developing appropriate therapeutic approaches. Diseases that arise via a LOF mechanism are more amenable to be treated by conventional gene therapy, whereas DN and GOF mechanisms may require gene editing or targeting by small molecules. Moreover, pathogenic missense mutations that act via DN and GOF mechanisms are more difficult to identify than those that act via LOF using nearly all currently available variant effect predictors. Here, we introduce a tripartite statistical model made up of support vector machine binary classifiers trained to predict whether human protein coding genes are likely to be associated with DN, GOF, or LOF molecular disease mechanisms. We test the utility of the predictions by examining biologically and clinically meaningful properties known to be associated with the mechanisms. Our results strongly support that the models are able to generalise on unseen data and offer insight into the functional attributes of proteins associated with different mechanisms. We hope that our predictions will serve as a springboard for researchers studying novel variants and those of uncertain clinical significance, guiding variant interpretation strategies and experimental characterisation. Predictions for the human UniProt reference proteome are available at https://osf.io/z4dcp/.
Assuntos
Doenças Genéticas Inatas , Proteoma , Humanos , Doenças Genéticas Inatas/genética , Máquina de Vetores de Suporte , Genes Dominantes , Mutação de Sentido Incorreto , Mutação com Ganho de Função , Mutação com Perda de FunçãoRESUMO
BACKGROUND: Patients with von Hippel-Lindau (VHL) disease are at risk of developing tumors in the eye, brain, kidney, adrenal gland, and other organs based on their gene mutations. The VHL tumor suppressor gene contains pathogenic variants responsible for these events. This meta-analysis aims to investigate the genetic differences among the various types of VHL syndrome and their correlation with the location of mutations (exons and domains) in the VHL gene. METHOD: Papers eligible for publication until September 2023 were identified using the electronic databases of PubMed, Google Scholar, Scopus, and EMBASE. The Random Effect model was utilized to evaluate the genetic differences between type 1 and type 2 VHL syndromes. RESULTS: The prevalence of missense mutations (MSs) was found to be 58.9% in type 1, while it was 88.1% in type 2. Interestingly, the probability of observing MSs in type 1 was 0.42 times lower compared to type 2. The mutation hotspots of the VHL gene were R167Q/W, Y98H, R238W, and S65L, respectively. Although type 2 had a high presentation of Y98H and R238W, it did not have a higher S65L than type 1. The analysis demonstrated a statistically significant higher prevalence of truncated mutations (PTMs) in type 1. Among type 1, large/complete deletions (L/C DELs) were found in 16.9% of cases, whereas in type 2 only 3.7%. This difference was statistically significant with a p-value < 0.001. Overall, the probability of identifying mutations in domain 2 compared to domain 1 was found to be 2.13 times higher in type 1 (p-value < 0.001). Furthermore, the probability of detecting exon 1 in comparison with observing exon 2 in type 1 was 2.11 times higher than type 2 and revealed a statistically significant result (p-value < 0.001). The detection of exon 2 was 2.18 times higher in type 1 (p-value < 0.001). In addition, the likelihood of discovering exon 2 compared with others was significantly lower in type 1 compared with type 2 VHL (OR = 0.63, p-value = 0.015). CONCLUSIONS: We have revealed a comprehensive genetic difference between types 1 and 2 of VHL syndrome. The significant differences in MS, PTMs, L/C DELs, and the location of the mutations between type 1 and type 2 VHL patients in the Asian, European, and American populations emphasize the genetic heterogeneity of the syndrome. These findings may pave the way for the diagnosis, treatment, and further investigation of the mechanisms behind this complex genetic disorder.
Assuntos
Proteína Supressora de Tumor Von Hippel-Lindau , Doença de von Hippel-Lindau , Humanos , Doença de von Hippel-Lindau/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Mutação , Mutação de Sentido Incorreto , Predisposição Genética para DoençaRESUMO
The SP/KLF family of transcription factors harbour three C-terminal C2H2 zinc fingers interspersed by two linkers which confers DNA-binding to a 9-10 bp motif. Mutations in KLF1, the founding member of the family, are common. Missense mutations in linker two result in a mild phenotype. However, when co-inherited with loss-of-function mutations, they result in severe non-spherocytic hemolytic anemia. We generate a mouse model of this disease by crossing Klf1+/- mice with Klf1H350R/+ mice that harbour a missense mutation in linker-2. Klf1H350R/- mice exhibit severe hemolysis without thalassemia. RNA-seq demonstrate loss of expression of genes encoding transmembrane and cytoskeletal proteins, but not globins. ChIP-seq show no change in DNA-binding specificity, but a global reduction in affinity, which is confirmed using recombinant proteins and in vitro binding assays. This study provides new insights into how linker mutations in zinc finger transcription factors result in different phenotypes to those caused by loss-of-function mutations.
Assuntos
Hemólise , Fatores de Transcrição Kruppel-Like , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Animais , Camundongos , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Mutação de Sentido Incorreto , Humanos , Anemia Hemolítica/genética , Anemia Hemolítica/metabolismo , Camundongos Knockout , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Masculino , Dedos de Zinco , Feminino , MutaçãoRESUMO
A missense nucleotide substitution at codon 95 of HLA-C*18:01:01:01 creates a novel allele HLA-C*18:20.
Assuntos
Alelos , Éxons , Antígenos HLA-C , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade , Humanos , Antígenos HLA-C/genética , Teste de Histocompatibilidade/métodos , Códon , Mutação de Sentido Incorreto , Sequência de Bases , Análise de Sequência de DNA/métodos , Doadores de TecidosRESUMO
A boy, aged 7 months, presented with severe global developmental delay (GDD), refractory epilepsy, hypotonia, nystagmus, ocular hypertelorism, a broad nasal bridge, everted upper lip, a high palatal arch, and cryptorchidism. Genetic testing revealed a de novo heterozygous missense mutation of c.364G>A(p.E122K) in the EEF1A2 gene, and finally the boy was diagnosed with autosomal dominant developmental and epileptic encephalopathy 33 caused by the EEF1A2 gene mutation. This case report suggests that for children with unexplained infancy-onset severe to profound GDD/intellectual disability and refractory epilepsy, genetic testing for EEF1A2 gene mutations should be considered. This is particularly important for those exhibiting hypotonia, nonverbal communication, and craniofacial deformities, to facilitate a confirmed diagnosis.
Assuntos
Deficiências do Desenvolvimento , Fator 1 de Elongação de Peptídeos , Humanos , Masculino , Lactente , Deficiências do Desenvolvimento/genética , Fator 1 de Elongação de Peptídeos/genética , Epilepsia/genética , Mutação , Mutação de Sentido IncorretoRESUMO
Autosomal dominant hearing loss is represented by a large number of genetically determined forms. Over 50 genes associated with dominant nonsyndromic hearing impairments were described. Pathogenic variants in the CEACAM16 gene lead to the development of DFNA4B hearing loss. Currently, 8 pathogenic variants in this gene have been described. The objective of this study was to study the audiological and molecular genetic characteristics of a large family with CEACAM16-associated autosomal dominant nonsyndromic hearing loss. A detailed anamnesis was collected, and a comprehensive audiological examination was performed for 21 family members. Genetic testing was performed, including whole-genome sequencing for the proband's son and Sanger sequence analysis for the proband and for all available family members. In a large Russian family, including 5 generations, an autosomal dominant type of slowly progressing nonsyndromic late-onset hearing loss was observed. Eleven family members suffer from hearing impairment, which starts with tinnitus and threshold increase at high frequencies, since the age of 5-20 years. Hearing loss slowly progresses with age in each person and is similar to age-related hearing loss. We have detected the novel likely pathogenic variant Ñ.419С>T (p.(Thr140Ile)) in exon 3 of the CEACAM16 gene, which segregates with late-onset nonsyndromic hearing loss in this family. The clinical data obtained in the examined family correspond with the phenotype in previously described cases. In general, the study widened the mutation spectrum of the gene, allowing to carry out medical genetic counseling and to answer the questions about the hearing impairment prognosis for future generations.
Assuntos
Moléculas de Adesão Celular , Mutação de Sentido Incorreto , Linhagem , Fenótipo , Humanos , Masculino , Mutação de Sentido Incorreto/genética , Feminino , Adulto , Pessoa de Meia-Idade , Moléculas de Adesão Celular/genética , Federação Russa , Adolescente , Criança , Antígenos CD/genética , Adulto Jovem , Idoso , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/diagnóstico , Genes Dominantes , Pré-Escolar , Proteínas Ligadas por GPI/genética , SurdezRESUMO
Purpose: Biallelic pathogenic variants in the gene encoding the ATP-binding cassette transporter ABCA4 are the leading cause of irreversible vision loss in inherited retinal dystrophies (IRDs). Interpretation of ABCA4 variants is challenging, due to cis-modifying and hypomorphic variants. We have previously detected 10 missense variants of unknown significance (VUS) in patients with suspected ABCA4-retinal dystrophies (ABCA4-RDs) in Norway. In this study, we functionally characterized the VUS to aid interpretation of the variants and to determine if they are associated with the disease. Methods: The ABCA4 VUS were expressed in HEK293T cells and the ABCA4 expression level and ATPase activity were determined and correlated with the patients' phenotype. The functional data further used for reclassification of the VUS following the American College of Medical Genetics and Genomics (ACMG) guidelines. Results: Of the 10 VUSs, 2 variants, Cys205Phe and Asn415Thr, were categorized as functionally severe. The age at presentation in the 2 patients carrying these variants was divergent and seemed to be driven by the patients' second pathogenic variants Gly1961Glu and c.5461-10T>C, respectively. Three variants, Val643Gly, Pro799Leu, and Val1433Ile were categorized as functionally moderate, and were found in patients with intermediate/late age at presentation. The remaining five variants were categorized as functionally normal/mild. Based on our data, c.614G>T p.(Cys205Phe), c.1244A>C p.(Asn415Thr), and c.2396C>T p.(Pro799Leu) were reclassified to (likely) pathogenic, while 4 of the functionally normal/mild variants could be reclassified to likely benign. Conclusions: Functional analyses of ABCA4 variants are a helpful tool in variant classification and enable us to better predict the disease severity in patients with ABCA4-RDs.
Assuntos
Transportadores de Cassetes de Ligação de ATP , Mutação de Sentido Incorreto , Fenótipo , Distrofias Retinianas , Humanos , Distrofias Retinianas/genética , Distrofias Retinianas/metabolismo , Distrofias Retinianas/diagnóstico , Transportadores de Cassetes de Ligação de ATP/genética , Feminino , Masculino , Células HEK293 , Análise Mutacional de DNA , Linhagem , AdultoRESUMO
Somatic variation is a major type of genetic variation contributing to human diseases including cancer. Of the vast quantities of somatic variants identified, the functional impact of many somatic variants, in particular the missense variants, remains unclear. Lack of the functional information prevents the translation of rich variation data into clinical applications. We previously developed a method named Ramachandran Plot-Molecular Dynamics Simulations (RP-MDS), aiming to predict the function of germline missense variants based on their effects on protein structure stability, and successfully applied to predict the deleteriousness of unclassified germline missense variants in multiple cancer genes. We hypothesized that regardless of their different genetic origins, somatic missense variants and germline missense variants could have similar effects on the stability of their affected protein structure. As such, the RP-MDS method designed for germline missense variants should also be applicable to predict the function of somatic missense variants. In the current study, we tested our hypothesis by using the somatic missense variants in TP53 as a model. Of the 397 somatic missense variants analyzed, RP-MDS predicted that 195 (49.1%) variants were deleterious as they significantly disturbed p53 structure. The results were largely validated by using a p53-p21 promoter-green fluorescent protein (GFP) reporter gene assay. Our study demonstrated that deleterious somatic missense variants can be identified by referring to their effects on protein structural stability.
Assuntos
Mutação de Sentido Incorreto , Estabilidade Proteica , Proteína Supressora de Tumor p53 , Humanos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/química , Simulação de Dinâmica Molecular , Neoplasias/genética , Conformação ProteicaRESUMO
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-IdadeRESUMO
OBJECTIVE: To explore the genetic basis for child with CHARGE syndrome. METHODS: A child who was diagnosed at Ningbo Women and Children's Hospital on September 29, 2022 was selected as the study subject. Relevant clinical data were collected. The child and her parents were subjected to whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child was found to harbor a de novo c.2972T>C (p.L991S) missense variant of the CHD7 gene, which was detected in neither of her parents. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be likely pathogenic (PM6+PM2_Supporting+PP2+PP3+PP4). Bioinformatic analysis predicted that amino acid 991 is highly conserved among various species, and a hydrogen bond has formed between Asp993 and the mutant Ser991. CONCLUSION: The heterozygous c.2972T>C (p.L991S) missense variant of the CHD7 gene probably underlay the pathogenesis of CHARGE syndrome in this child. Above finding has also enriched the mutational spectrum for CHARGE syndrome.
Assuntos
Síndrome CHARGE , DNA Helicases , Proteínas de Ligação a DNA , Mutação de Sentido Incorreto , Humanos , Síndrome CHARGE/genética , DNA Helicases/genética , Feminino , Proteínas de Ligação a DNA/genética , Sequenciamento do Exoma , Lactente , Sequência de AminoácidosRESUMO
Alport syndrome is a hereditary kidney disease caused by collagen IV mutations that interfere with the formation and deposition of the α3α4α5 protomer into the glomerular basement membrane. In this issue, Yu et al. show that the chemical chaperone tauroursodeoxycholic acid prevented kidney structural changes and function decline in mice with a pathogenic missense Col4a3 mutation by increasing mutant α3α4α5 protomer glomerular basement membrane deposition and preventing podocyte apoptosis induced by endoplasmic reticulum stress.
Assuntos
Autoantígenos , Colágeno Tipo IV , Membrana Basal Glomerular , Nefrite Hereditária , Ácido Tauroquenodesoxicólico , Nefrite Hereditária/genética , Nefrite Hereditária/tratamento farmacológico , Nefrite Hereditária/patologia , Nefrite Hereditária/metabolismo , Animais , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Ácido Tauroquenodesoxicólico/farmacologia , Ácido Tauroquenodesoxicólico/uso terapêutico , Camundongos , Membrana Basal Glomerular/patologia , Membrana Basal Glomerular/efeitos dos fármacos , Humanos , Autoantígenos/genética , Autoantígenos/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Podócitos/efeitos dos fármacos , Podócitos/patologia , Podócitos/metabolismo , Mutação de Sentido Incorreto , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismoRESUMO
BACKGROUND: This study aims to report the clinical characteristics of a child with autosomal recessive polycystic kidney disease (ARPKD) within a Chinese Zhuang ethnic family. METHODS: We used whole exome sequencing (WES) in the family to examine the genetic cause of the disease. Candidate pathogenic variants were validated by Sanger sequencing. RESULTS: We identified previously unreported mutations in the PKHD1 gene of the proband with ARPKD through WES: a splice site mutation c.6809-2Aâ >â T, a nonsense mutation c.4192Câ >â T(p.Gln1398Ter), and a missense mutation c.2181Tâ >â G(p.Asn727Lys). Her mother is a heterozygous carrier of c.2181Tâ >â G(p.Asn727Lys) mutation. Her father is a carrier of c.6809-2Aâ >â T mutation and c.4192Câ >â T(p.Gln1398Ter) mutation. CONCLUSIONS: The identification of novel mutations in the PKHD1 gene through WES not only expands the spectrum of known variants but also potentially enhances genetic counseling and prenatal diagnostic approaches for families affected by ARPKD.
Assuntos
Códon sem Sentido , Linhagem , Rim Policístico Autossômico Recessivo , Receptores de Superfície Celular , Humanos , Rim Policístico Autossômico Recessivo/genética , Receptores de Superfície Celular/genética , Feminino , China , Masculino , Sequenciamento do Exoma , Povo Asiático/genética , Sítios de Splice de RNA/genética , Mutação de Sentido Incorreto , Adulto , População do Leste AsiáticoRESUMO
BACKGROUND: Exercise-induced pulmonary haemorrhage (EIPH) in athletic horses is characterized by the presence of blood from the lungs in the tracheobronchial tree after intense exercise. Despite the high prevalence of EIPH in horses, the primary aetiology remains unknown. Variants in the genes encoding CD39 and CD39L1 (ENTPD1 and ENTPD2, respectively) were previously reported as potential genetic causes involved in EIPH pathogenesis. However, the role of these variants in haemostatic functions is unknown. RESULTS: To investigate the association between EIPH and missense variants in the ENTPD1 (rs1152296272, rs68621348, and rs68621347) and ENTPD2 genes (rs782872967), 76 Thoroughbred horses diagnosed with EIPH and 56 without clinical signs of EIPH (control group) by trachea-bronchial endoscopy were genotyped. The rs1152296272 and rs68621347 variants were linked, which explained why the same results were found in all horses. Approximately 96% and 95% of the EIPH and control horses, respectively, carried at least one nonreference allele for these variants. In contrast, 100% of the control horses and 96% of the EIPH horses were homozygous for the reference allele for the rs68621348 variant. In the EIPH group, 1.5% of the horses were homozygotes and 24% were heterozygous for the nonreference allele of the rs782872967 variant. In the control group, the nonreference allele of this variant was observed only in heterozygotes (16%). There were no significant differences between groups for any of the variants. CONCLUSIONS: The variants previously described in the genes encoding the CD39 and CD39L1 enzymes were highly present in the studied population. However, no association was found between the occurrence of EIPH and the presence of these variants in Thoroughbred horses in this study.
Assuntos
Hemorragia , Doenças dos Cavalos , Pneumopatias , Condicionamento Físico Animal , Animais , Cavalos , Doenças dos Cavalos/genética , Hemorragia/veterinária , Hemorragia/genética , Pneumopatias/veterinária , Pneumopatias/genética , Masculino , Apirase/genética , Feminino , Predisposição Genética para Doença , Genótipo , Mutação de Sentido IncorretoRESUMO
Biallelic loss-of-function variants in the IYD gene cause hypothyroidism resulting from iodine wasting. We describe 8 patients (from 4 families in which the parents are first cousins) who are homozygous for a variant in IYD (including a novel missense deleterious variant, c.791C>T [P264L], in 1 family). Seven patients presented between 5 and 16 years of age with a large goiter, overt hypothyroidism, and a high serum thyroglobulin. The goiter subsided with levothyroxine therapy in most. Upon stopping levothyroxine in 5 patients, goiter and hypothyroidism reappeared in 3. In these 3 patients, a rising serum thyroglobulin concentration preceded hypothyroidism and goiter and urinary iodine excretion was low. In patients who remained euthyroid, urinary iodine was normal. In conclusion, these patients bearing biallelic pathogenic variants in IYD developed a large goiter, a high serum thyroglobulin, and overt hypothyroidism when their iodine intake was low.
Assuntos
Bócio , Hipotireoidismo , Linhagem , Tiroxina , Humanos , Feminino , Masculino , Adolescente , Hipotireoidismo/genética , Criança , Pré-Escolar , Tiroxina/uso terapêutico , Bócio/genética , Tireoglobulina/genética , Iodo/deficiência , Alelos , Mutação de Sentido Incorreto , SimportadoresRESUMO
Proteins, as crucial macromolecules performing diverse biological roles, are central to numerous biological processes. The ability to predict changes in protein thermal stability due to mutations is vital for both biomedical research and industrial applications. However, existing experimental methods are often costly and labor-intensive, while structure-based prediction methods demand significant computational resources. In this study, we introduce PON-Tm, a novel sequence-based method for predicting mutation-induced thermal stability variations in proteins. PON-Tm not only incorporates features predicted by a protein language model from protein sequences but also considers environmental factors such as pH and the thermostability of the wild-type protein. To evaluate the effectiveness of PON-Tm, we compared its performance to four well-established methods, and PON-Tm exhibited superior predictive capabilities. Furthermore, to facilitate easy access and utilization, we have developed a web server.
Assuntos
Mutação de Sentido Incorreto , Estabilidade Proteica , Proteínas , Proteínas/química , Proteínas/genética , Biologia Computacional/métodos , Sequência de Aminoácidos , SoftwareRESUMO
We investigate the etiology of amyotrophic lateral sclerosis (ALS) in a 35-year-old woman presenting with progressive weakness in her left upper limb. Prior to sequencing, a comprehensive neurological work-up was performed, including neurological examination, electrophysiology, biomarker assessment, and brain and spinal cord MRI. Six months before evaluation, the patient experienced weakness and atrophy in her left hand, accompanied by brisk reflexes and Hoffman sign in the same arm. Electroneuromyography revealed lower motor neuron involvement in three body regions. Neurofilament light chains were elevated in her cerebrospinal fluid. Brain imaging showed asymmetrical T2 hyperintensity of the corticospinal tracts and T2 linear hypointensity of the precentral gyri. Trio genome sequencing identified a likely pathogenic de novo variant in the KIF1A gene (NM_001244008.2): c.574A>G, p.(Ile192Val). Pathogenic variants in KIF1A have been associated with a wide range of neurological manifestations called KIF1A-associated neurological diseases (KAND). This report describes a likely pathogenic de novo variant in KIF1A associated with ALS, expanding the phenotypic spectrum of KAND and our understanding of the pathophysiology of ALS.
Assuntos
Esclerose Lateral Amiotrófica , Cinesinas , Mutação de Sentido Incorreto , Humanos , Cinesinas/genética , Esclerose Lateral Amiotrófica/genética , Feminino , Adulto , Extremidade Superior/fisiopatologia , Extremidade Superior/patologia , Imageamento por Ressonância MagnéticaRESUMO
BACKGROUND: The apparent lack of additional missense mutations data on mixed-phenotype leukemia is noteworthy. Single amino acid substitution by these non-synonymous single nucleotide variations can be related to many pathological conditions and may influence susceptibility to disease. This case-control study aimed to unravel whether the ZAP70 missense variant (rs104893674 (C > A)) underpinning mixed-phenotype leukemia. METHODS: The rs104893674 was genotyped in clients who were mixed-phenotype acute leukemia-, acute lymphoblastic leukemia- and acute myeloid leukemia-positive and matched healthy controls, which have been referred to all major urban hospitals from multiple provinces of country- wide, IRAN, from February 11' 2019 to June 10' 2023, by amplification refractory mutation system-polymerase chain reaction method. Direct sequencing for rs104893674 of the ZAP70 gene was performed in a 3130 Genetic Analyzer. RESULTS: We found that the AC genotype of individuals with A allele at this polymorphic site (heterozygous variant-type) contribute to the genetic susceptibility to acute leukemia of both forms, acute myeloid leukemia and acute lymphoblastic leukemia as well as with a mixed phenotype. In other words, the ZAP70 missense variant (rs104893674 (C > A)) increases susceptibility of distinct cell populations of different (myeloid and lymphoid) lineages to exhibiting cancer phenotype. The results were all consistent with genotype data obtained using a direct DNA sequencing technique. CONCLUSION: Of special interest are pathogenic missense mutations, since they generate variants that cause specific molecular phenotypes through protein destabilization. Overall, we discovered that the rs104893674 (C > A) variant chance in causing mixed-phenotype leukemia is relatively high.
Assuntos
Predisposição Genética para Doença , Leucemia Mieloide Aguda , Mutação de Sentido Incorreto , Leucemia-Linfoma Linfoblástico de Células Precursoras , Proteína-Tirosina Quinase ZAP-70 , Humanos , Proteína-Tirosina Quinase ZAP-70/genética , Estudos de Casos e Controles , Masculino , Feminino , Adulto , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Pessoa de Meia-Idade , Leucemia Mieloide Aguda/genética , Adulto Jovem , Genótipo , Polimorfismo de Nucleotídeo Único , AdolescenteRESUMO
Most cases of human prion disease arise due to spontaneous misfolding of WT or mutant prion protein, yet recapitulating this event in animal models has proven challenging. It remains unclear whether spontaneous prion generation can occur within the mouse lifespan in the absence of protein overexpression and how disease-causing mutations affect prion strain properties. To address these issues, we generated knockin mice that express the misfolding-prone bank vole prion protein (BVPrP). While mice expressing WT BVPrP (I109 variant) remained free from neurological disease, a subset of mice expressing BVPrP with mutations (D178N or E200K) causing genetic prion disease developed progressive neurological illness. Brains from spontaneously ill knockin mice contained prion disease-specific neuropathological changes as well as atypical protease-resistant BVPrP. Moreover, brain extracts from spontaneously ill D178N- or E200K-mutant BVPrP-knockin mice exhibited prion seeding activity and transmitted disease to mice expressing WT BVPrP. Surprisingly, the properties of the D178N- and E200K-mutant prions appeared identical before and after transmission, suggesting that both mutations guide the formation of a similar atypical prion strain. These findings imply that knockin mice expressing mutant BVPrP spontaneously develop a bona fide prion disease and that mutations causing prion diseases may share a uniform initial mechanism of action.
Assuntos
Modelos Animais de Doenças , Técnicas de Introdução de Genes , Camundongos Transgênicos , Doenças Priônicas , Proteínas Priônicas , Animais , Camundongos , Doenças Priônicas/genética , Doenças Priônicas/patologia , Doenças Priônicas/metabolismo , Proteínas Priônicas/genética , Proteínas Priônicas/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Mutação de Sentido Incorreto , Humanos , Arvicolinae/genética , Arvicolinae/metabolismo , Substituição de Aminoácidos , Príons/genética , Príons/metabolismo , Dobramento de ProteínaRESUMO
BACKGROUND: Alström syndrome (AS) is a rare autosomal recessive disorder that leads to multiple organ fibrosis and failure. Precise diagnosis from the clinical symptoms is challenging due to its highly variabilities and its frequent confusion with other ciliopathies and genetic diseases. Currently, mutations in the ALMS1 gene have been reported as a major cause of AS, thus, it is crucial to focus on the detection and discovery of ALMS1 mutations. CASE PRESENTATION: We present a case of a 13-year-old Chinese boy weighing 70 kg and standing 168 cm tall. He has two younger brothers. Their parents hail from different ancestral homes in eastern and northern China. The patient's primary clinical findings included visual impairment at the age of four and progressive hearing loss starting at the age of ten. Subsequently, at the age of twelve, the patient developed hyperlipidaemia and hyperinsulinemia. Ultrasonographic findings indicated the presence of gallstones and mild fatty liver. His Body Mass Index (BMI) significantly increased to 25 kg/m2 (ref: 18.5-23.9 kg/m2). Additionally, echocardiography revealed mild mitral and tricuspid regurgitation. Ultimately, Whole Exome Sequencing (WES) identified a new missense mutation in the ALMS1 gene (NG_011690.1 (NM_015120): c.9536G > A (p.R3179Q)). This missense mutation generated an aberrant splicer and disrupted the stability and hydrophobicity of proteins, which preliminarily determined as " likely pathogenic". Therefore, considering all the above symptoms and molecular analysis, we deduced that the patient was diagnosed with AS according to the guidelines. We recommended that he continue wearing glasses and undergo an annual physical examination. CONCLUSION: In this case report, we report a novel homozygous ALMS1 mutation associated with AS in the Chinese population, which expands the mutation spectrum of ALMS1. Genetic testing indeed should be incorporated into the diagnosis of syndromic deafness, as it can help avoid misdiagnoses of AS. While there is no specific treatment for AS, early diagnosis and intervention can alleviate the progression of some symptoms and improve patients' quality of life.
Assuntos
Síndrome de Alstrom , Proteínas de Ciclo Celular , Sequenciamento do Exoma , Humanos , Masculino , Síndrome de Alstrom/genética , Síndrome de Alstrom/diagnóstico , Adolescente , Proteínas de Ciclo Celular/genética , Mutação de Sentido Incorreto , Linhagem , China , População do Leste AsiáticoRESUMO
Understanding and treating human diseases require valid animal models. Leveraging the genetic diversity in rhesus macaque populations across eight primate centers in the United States, we conduct targeted-sequencing on 1845 individuals for 374 genes linked to inherited human retinal and neurodevelopmental diseases. We identify over 47,000 single nucleotide variants, a substantial proportion of which are shared with human populations. By combining rhesus and human allele frequencies with established variant prediction methods, we develop a machine learning-based score that outperforms established methods in predicting missense variant pathogenicity. Remarkably, we find a marked number of loss-of-function variants and putative deleterious variants, which may lead to the development of rhesus disease models. Through phenotyping of macaques carrying a pathogenic OPA1:p.A8S variant, we identify a genetic model of autosomal dominant optic atrophy. Finally, we present a public website housing variant and genotype data from over two thousand rhesus macaques.