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Epilepsy, characterized by recurrent seizures, impacts 70-80% of patients, leading to cognitive deficits. The intricate relationship between seizure control and cognitive impairment remains complex. Epileptic encephalopathy (EE), an intensified form often rooted in genetic factors, is detectable through next-generation sequencing, aiding in precise diagnoses, family counseling, and potential treatment strategies. We present a case involving two sisters with refractory generalized seizures evolving into dysarthria, dysphagia, ataxia, and cognitive decline. Despite normal physical exams, abnormal electroencephalogram results consistent with epilepsy were noted. Whole Exome Sequencing identified heterozygous variants in the alanyl-tRNA synthetase (AARS) and Calcium Voltage-Gated Channel Subunit Alpha 1 (CACNA1A) genes. The AARS variant (c.C2083T, p.R695*) was maternal, while the CACNA1A variant (c.G7400C, p.R2467P) was paternal. Patients A and B exhibited a unique blend of neurological and psychiatric conditions, distinct from common disorders that begin adolescence, like Juvenile Myoclonic Epilepsy. Whole Exome Sequencing uncovered an AARS gene and CACNA1A gene, linked to various autosomal dominant phenotypes. Presence in both parents, coupled with familial reports of migraines and seizures, provides insight into accelerated symptom progression. This study underscores the importance of genetic testing in decoding complex phenotypes and emphasizes the value of documenting family history for anticipating related symptoms and future health risks.
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The Waorani, an isolated indigenous tribe in Ecuador, have long been characterized by limited genetic diversity, with few studies delving into their genetic background. Human Leukocyte Antigen (HLA) genes which are located in the human major histocompatibility complex (MHC) provides valuable insights into population evolution due to its highly polymorphic nature. However, little is known about the HLA diversity and ancestry of the Waorani population. In this study, we sequenced eight HLA genes using Next Generation Sequencing (NGS) from 134 Waorani individuals and obtained up to four-field HLA allele resolution. Cluster and phylogenetic analysis show that the Waorani are genetically distant from other Ecuador populations, but instead show genetic affinities with the Puyanawa and Terena tribes from Brazil, as well as the Mixe tribe from Mexico. The identification of alleles common within the Waorani population, previously linked to specific health conditions, notably paves the way for future association analyses. This extensive study, employing Next-Generation Sequencing (NGS) technology, significantly enriches the sparse and segmented understanding of HLA diversity in the South American region. Our findings enhance the global comprehension of human genetic diversity and underscore the value of studying indigenous populations. Such research is vital for deepening our insights into human migration patterns and evolutionary processes.
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Frequência do Gene , Variação Genética , Genética Populacional , Antígenos HLA , Filogenia , Humanos , Alelos , Equador , Etnicidade/genética , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Antígenos HLA/genética , Migração HumanaRESUMO
Background: Campomelic dysplasia (CD) is a rare disorder that involves the skeletal and genital systems. This condition has been associated with a diverse set of mutations in the SRY-box transcription factor 9 (SOX9) gene. Case presentation: We herein report a case involving a 4-year-old female patient with CD, female sex reversal, type 1 Arnold-Chiari malformation, and bilateral conductive hearing loss and investigate the causal mutation. Whole-exome sequencing analysis detected a novel Trp115X* variant in the SOX9 gene. We performed a literature review of the reported cases and demonstrated that the missense variants were located only in the self-dimerization domain (DIM) and high-mobility group box domains. We also reported that variants in the DIM domain do not cause sex reversal and identified that the amino acid sequences that were mutated in the patients with campomelic dysplasia are evolutionarily conserved among primates. Conclusions: We suggest that missense variants cannot be located in the K2, PQA, and PQS given that these domains function critically for transcriptional activation or repression of target genes and evolve under purifying selection.
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Multiple non-related neoplasia does not have an established approach or benefits for performing whole-exome sequencing (WES) analysis. We report on a 46-year-old woman who developed astrocytoma, thyroid, and breast cancer within 10 years. The WES analysis found a novel missense variant in the ACSL6 gene, and the protein modeling showed altered secondary and tertiary structures, which modify the binding to cofactors and substrates. ACSL6 is involved in lipid metabolism, expressed in the brain, thyroid, and breast tissues, and is associated with diverse types of cancer. Our study demonstrates the benefit of WES analysis compared with commercial panels in patients with non-related neoplasia.
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BACKGROUND: The diagnostic process for uncommon disorders with similar manifestations is complicated and requires newer technology, like gene sequencing for a correct diagnosis. MAIN BODY: We described two brothers clinically diagnosed with Carpenter syndrome, which is a condition characterized by the premature fusion of certain skull bones (craniosynostosis), abnormalities of the fingers and toes, and other developmental problems, for which they underwent craniotomies. However, whole exome sequencing analysis concluded a novel pathological variation in the ATRX chromatin remodeler gene and protein remodeling demonstrated structural variations that decreased the function, giving a completely different diagnosis to these patients. CONCLUSION: Our study focuses on the importance of using newer technologies, such as whole exome sequencing analysis, in patients with ambiguous phenotypes.
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Acrocefalossindactilia/genética , Deficiência Intelectual Ligada ao Cromossomo X/genética , Proteínas Nucleares/genética , Proteína Nuclear Ligada ao X/genética , Talassemia alfa/genética , Acrocefalossindactilia/patologia , DNA Helicases/genética , Exoma/genética , Humanos , Deficiência Intelectual Ligada ao Cromossomo X/patologia , Mutação/genética , Fenótipo , Sequenciamento do Exoma , Talassemia alfa/patologiaRESUMO
BACKGROUND: Bovine leukemia virus (BLV) is a member of retroviridae family, together with human T cell leukemia virus types 1 and 2 (HTLV-1 and -2) belonging to the genes deltaretrovirus, and infects cattle worldwide. Previous studies have classified the env sequences of BLV provirus from different geographic locations into eight genetic groups. To investigate the genetic variability of BLV in South America, we performed phylogenetic analyses of whole genome and partial env gp51 sequences of BLV strains isolated from Peru, Paraguay and Bolivia, for which no the molecular characteristics of BLV have previously been published, and discovered a novel BLV genotype, genotype-9, in Bolivia. RESULTS: In Peru and Paraguay, 42.3 % (139/328) and over 50 % (76/139) of samples, respectively, were BLV positive. In Bolivia, the BLV infection rate was up to 30 % (156/507) at the individual level. In Argentina, 325/420 samples were BLV positive, with a BLV prevalence of 77.4 % at the individual level and up to 90.9 % at herd level. By contrast, relatively few BLV positive samples were detected in Chile, with a maximum of 29.1 % BLV infection at the individual level. We performed phylogenetic analyses using two different approaches, maximum likelihood (ML) tree and Bayesian inference, using 35 distinct partial env gp51 sequences from BLV strains isolated from Peru, Paraguay, and Bolivia, and 74 known BLV strains, representing eight different BLV genotypes from various geographical locations worldwide. The results indicated that Peruvian and Paraguayan BLV strains were grouped into genotypes-1, -2, and -6, while those from Bolivia were clustered into genotypes-1, -2, and -6, and a new genotype, genotype-9. Interestingly, these results were confirmed using ML phylogenetic analysis of whole genome sequences obtained by next generation sequencing of 25 BLV strains, assigned to four different genotypes (genotypes-1, -2, -6, and -9) from Peru, Paraguay, and Bolivia. Comparative analyses of complete genome sequences clearly showed some specific substitutions, in both structural and non-structural BLV genes, distinguishing the novel genotype-9 from known genotypes. CONCLUSIONS: Our results demonstrate widespread BLV infection in South American cattle and the existence of a new BLV genotype-9 in Bolivia. We conclude that at least seven BLV genotypes (genotypes-1, -2, -4, -5, -6, -7, and -9) are circulating in South America.