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Patatin-like phospholipase domain-containing lipase 8 (PNPLA8), one of the calcium-independent phospholipase A2 enzymes, is involved in various physiological processes through the maintenance of membrane phospholipids. Biallelic variants in PNPLA8 have been associated with a range of paediatric neurodegenerative disorders. However, the phenotypic spectrum, genotype-phenotype correlations and the underlying mechanisms are poorly understood. Here, we newly identified 14 individuals from 12 unrelated families with biallelic ultra-rare variants in PNPLA8 presenting with a wide phenotypic spectrum of clinical features. Analysis of the clinical features of current and previously reported individuals (25 affected individuals across 20 families) showed that PNPLA8-related neurological diseases manifest as a continuum ranging from variable developmental and/or degenerative epileptic-dyskinetic encephalopathy to childhood-onset neurodegeneration. We found that complete loss of PNPLA8 was associated with the more profound end of the spectrum, with congenital microcephaly. Using cerebral organoids generated from human induced pluripotent stem cells, we found that loss of PNPLA8 led to developmental defects by reducing the number of basal radial glial cells and upper-layer neurons. Spatial transcriptomics revealed that loss of PNPLA8 altered the fate specification of apical radial glial cells, as reflected by the enrichment of gene sets related to the cell cycle, basal radial glial cells and neural differentiation. Neural progenitor cells lacking PNPLA8 showed a reduced amount of lysophosphatidic acid, lysophosphatidylethanolamine and phosphatidic acid. The reduced number of basal radial glial cells in patient-derived cerebral organoids was rescued, in part, by the addition of lysophosphatidic acid. Our data suggest that PNPLA8 is crucial to meet phospholipid synthetic needs and to produce abundant basal radial glial cells in human brain development.
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Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare neurodegenerative disorder of childhood. According to the previous reports, it has various primary signs and symptoms. Because of the simple treatment with riboflavin supplementation, it is important to have suspicious to this disease and begin treatment even before genetic test confirm. We report a five-year-old girl with BVVLS that manifest with hearing problems, first. There was obvious improvement in her disease clinical signs with riboflavin supplementation treatment.
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Heterozygous RTN2 variants have been previously identified in a limited cohort of families affected by autosomal dominant spastic paraplegia (SPG12-OMIM:604805) with a variable age of onset. Nevertheless, the definitive validity of SPG12 remains to be confidently confirmed due to the scarcity of supporting evidence. In this study, we identified and validated seven novel or ultra-rare homozygous loss-of-function RTN2 variants in 14 individuals from seven consanguineous families with distal hereditary motor neuropathy (dHMN) using exome, genome and Sanger sequencing coupled with deep-phenotyping. All affected individuals (seven males and seven females, aged 9-50â years) exhibited weakness in the distal upper and lower limbs, lower limb spasticity and hyperreflexia, with onset in the first decade of life. Nerve conduction studies revealed axonal motor neuropathy with neurogenic changes in the electromyography. Despite a slowly progressive disease course, all patients remained ambulatory over a mean disease duration of 19.71 ± 13.70â years. Characterization of Caenorhabditis elegans RTN2 homologous loss-of-function variants demonstrated morphological and behavioural differences compared with the parental strain. Treatment of the mutant with an endoplasmic/sarcoplasmic reticulum Ca2+ reuptake inhibitor (2,5-di-tert-butylhydroquinone) rescued key phenotypic differences, suggesting a potential therapeutic benefit for RTN2-disorder. Despite RTN2 being an endoplasmic reticulum (ER)-resident membrane shaping protein, our analysis of patient fibroblast cells did not find significant alterations in ER structure or the response to ER stress. Our findings delineate a distinct form of autosomal recessive dHMN with pyramidal features associated with RTN2 deficiency. This phenotype shares similarities with SIGMAR1-related dHMN and Silver-like syndromes, providing valuable insights into the clinical spectrum and potential therapeutic strategies for RTN2-related dHMN.
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Linhagem , Humanos , Masculino , Feminino , Criança , Adulto , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Animais , Extremidade Inferior/fisiopatologia , Caenorhabditis elegans , Espasticidade Muscular/genética , Espasticidade Muscular/fisiopatologia , Paraplegia Espástica Hereditária/genética , Paraplegia Espástica Hereditária/fisiopatologia , MutaçãoRESUMO
Lissencephaly (LIS) is a malformation of cortical development due to deficient neuronal migration and abnormal formation of cerebral convolutions or gyri. Thirty-one LIS-associated genes have been previously described. Recently, biallelic pathogenic variants in CRADD and PIDD1, have associated with LIS impacting the previously established role of the PIDDosome in activating caspase-2. In this report, we describe biallelic truncating variants in CASP2, another subunit of PIDDosome complex. Seven patients from five independent families presenting with a neurodevelopmental phenotype were identified through GeneMatcher-facilitated international collaborations. Exome sequencing analysis was carried out and revealed two distinct novel homozygous (NM_032982.4:c.1156delT (p.Tyr386ThrfsTer25), and c.1174 C > T (p.Gln392Ter)) and compound heterozygous variants (c.[130 C > T];[876 + 1 G > T] p.[Arg44Ter];[?]) in CASP2 segregating within the families in a manner compatible with an autosomal recessive pattern. RNA studies of the c.876 + 1 G > T variant indicated usage of two cryptic splice donor sites, each introducing a premature stop codon. All patients from whom brain MRIs were available had a typical fronto-temporal LIS and pachygyria, remarkably resembling the CRADD and PIDD1-related neuroimaging findings. Other findings included developmental delay, attention deficit hyperactivity disorder, hypotonia, seizure, poor social skills, and autistic traits. In summary, we present patients with CASP2-related ID, anterior-predominant LIS, and pachygyria similar to previously reported patients with CRADD and PIDD1-related disorders, expanding the genetic spectrum of LIS and lending support that each component of the PIDDosome complex is critical for normal development of the human cerebral cortex and brain function.
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Lisencefalia , Transtornos do Neurodesenvolvimento , Humanos , Caspase 2/genética , Lisencefalia/diagnóstico por imagem , Lisencefalia/genética , Alelos , Transtornos do Neurodesenvolvimento/genética , Códon sem Sentido , Fenótipo , Cisteína Endopeptidases/genéticaRESUMO
Background: The phenotypic range of limb-girdle muscular dystrophies (LGMDs) varies significantly because of genetic heterogeneity ranging from very mild to severe forms. Molecular analysis of the DYSF gene is challenging due to the wide range of mutations and associated complications in interpretations of novel DYSF variants with uncertain significance. Thus, in the current study, we performed the NGS analysis and its results are confirmed with Sanger sequencing to find the plausible disease-causing variants in patients with muscular dystrophy and their relatives via segregation analysis. Materials and Methods: Nine patients with LGMD type 2B (LGMD2B) characteristics were screened for putative mutations by the whole-exome sequencing (WES) test. Either the patients themselves or their parents and first relatives were investigated in the segregation analysis through Sanger sequencing. The majority of variants were classified as pathogenic through American College of Medical Genetics and Genomics (ACMG) guidelines, segregation results, and in silico predictions. Results: Results revealed eight variants in DYSF gene, including three splicing (c.1149+4A>G, c.2864+1G>A, and c.5785-7G>A), two nonsense (p.Gln112Ter and p.Trp2084Ter), two missense (p.Thr1546Pro and p.Tyr1032Cys), and one frameshift (p.Asp1067Ilefs), among nine Iranian families. One of the eight identified variants was novel, including p.Asp1067Ilefs, which was predicted to be likely pathogenic based on the ACMG guidelines. Notably, prediction tools suggested the damaging effects of studied variants on dysferlin structure. Conclusion: Conclusively, the current report introduced eight variants including a novel frameshift in DYSF gene with noticeable pathogenic effects. This study significantly can broaden the diagnostic spectrum of LGMD2B in combination with previous reports about DYSF mutations and may pave the way for a rapidly high-ranked identification of the accurate type of dysferlinopathy.
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Background: Congenital liver disease refers to a group of heterogeneous diseases from a clinical genetic point of view. The most crucial features are hepatosplenomegaly and elevated liver enzymes. This study aims to identify genetic variants causing the disease in three Iranian families with congenital liver disease using molecular techniques. Methods: Patients were referred to Next Generation Genetic Polyclinic (NGGC) in Mashhad after confirmed congenital liver disease diagnosis by gastroenterologists. Following informed consent signed by participants, DNA was extracted from blood samples. Whole exome sequencing (WES) was performed for three probands. After the analysis of raw data, candidate variants were confirmed in the patients and their parents. Results: We have found the possible disease-causing variant as the c.1718G>C variant (p. Trp573Ser) in the SMPD1 gene in the F-1 patient and c.1718G>C (p. Trp573Ser) in the SMPD1 gene in the F-3 patient. Moreover, we have found the c.3175C>T variant (p. Arg1059Ter) in the NPC1 gene in the F-2 patient. Conclusions: In this study, disease-causing variants were identified in three probands suspected of Niemann-Pick disease. Such results show the relatively high power of molecular techniques to assist clinicians with disease management, therapeutic strategies, and preventive options such as preimplantation genetic diagnosis and prenatal diagnosis.
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Congenital myotonia is a non-dystrophic musculoskeletal disease that causes abnormal muscle relaxation. The prevalence of congenital disorders is notably high in Iran, emphasizing the importance of genetic assessment in suspicious cases. In this study, we aim to report cases with the chloride channel gene, CLCN1, mutations leading to significant morbidity. This case report study investigated four patients from four families with clinically defined congenital myotonia. Inclusion criteria were increased creatinine kinase (CK) and muscle stiffness. We collected data regarding family history, age of onset, and current therapeutic plan. All patients underwent skeletal muscle electromyography, cardiological evaluation, spirometry study, and hematochemistry assessment, including but not limited to muscle enzyme levels. Afterward, DNA was extracted from peripheral blood. Subsequently, whole exome sequencing (WES) and Sanger sequencing were done to detect and confirm variants, respectively. Age of onset ranged from 1 to 12 years in these patients, which are years apart from their first visit to the clinic. The warm-up phenomenon was present in all of them. A variant of uncertain clinical significance was found. We recommend that future research projects should study the efficiency of collaboration between clinicians, molecular geneticists, and other healthcare providers in order to find out about unclear variants as quickly as possible.
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OBJECTIVE: Intracellular signaling networks rely on proper membrane organization to control an array of cellular processes such as metabolism, proliferation, apoptosis, and macroautophagy in eukaryotic cells and organisms. Phosphatidylinositol 4-phosphate (PI4P) emerged as an essential regulatory lipid within organelle membranes that defines their lipid composition and signaling properties. PI4P is generated by four distinct phosphatidylinositol 4-kinases (PI4K) in mammalian cells: PI4KA, PI4KB, PI4K2A, PI4K2B. Animal models and human genetic studies suggest vital roles of PI4K enzymes in development and function of various organs, including the nervous system. Bi-allelic variants in PI4KA were recently associated with neurodevelopmental disorders (NDD), brain malformations, leukodystrophy, primary immunodeficiency, and inflammatory bowel disease. Here, we describe patients from two unrelated consanguineous families with PI4K2A deficiency and functionally explored the pathogenic mechanism. METHODS: Two patients with PI4K2A deficiency were identified by exome sequencing, presenting with developmental and epileptic-dyskinetic encephalopathy. Neuroimaging showed corpus callosum dysgenesis, diffuse white matter volume loss, and hypoplastic vermis. In addition to NDD, we observed recurrent infections and death at toddler age. We further explored identified variants with cellular assays. RESULTS: This clinical presentation overlaps with what was previously reported in two affected siblings with homozygous nonsense PI4K2A variant. Cellular studies analyzing these human variants confirmed their deleterious effect on PI4K2A activity and, together with the central role of PI4K2A in Rab7-associated vesicular trafficking, establish a link between late endosome-lysosome defects and NDD. INTERPRETATION: Our study establishes the genotype-phenotype spectrum of PI4K-associated NDD and highlights several commonalities with other innate errors of intracellular trafficking.
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Epilepsia Generalizada , Antígenos de Histocompatibilidade Menor , Malformações do Sistema Nervoso , Transtornos do Neurodesenvolvimento , Fosfotransferases (Aceptor do Grupo Álcool) , Epilepsia Generalizada/genética , Homozigoto , Humanos , Antígenos de Histocompatibilidade Menor/genética , Malformações do Sistema Nervoso/genética , Transtornos do Neurodesenvolvimento/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genéticaRESUMO
Biallelic mutations in the TTC5 gene have been associated with autosomal recessive intellectual disability (ARID) and subsequently with an ID syndrome including severe speech impairment, cerebral atrophy, and hypotonia as clinical cornerstones. A TTC5 role in IDs has been proposed based on the physical interaction of TTC5 with p300, and possibly reducing p300 co-activator complex activity, similarly to what was observed in Menke-Hennekam 1 and 2 patients (MKHK1 and 2) carrying, respectively, mutations in exon 30 and 31 of CREBBP and EP300, which code for the TTC5-binding region. Recently, TTC5-related brain malformation has been linked to tubulinopathies due to the function of TTC5 in tubulins' dynamics. We reported seven new patients with novel or recurrent TTC5 variants. The deep characterization of the molecular and phenotypic spectrum confirmed TTC5-related disorder as a recognizable, very severe neurodevelopmental syndrome. In addition, other relevant clinical aspects, including a severe pre- and postnatal growth retardation, cryptorchidism, and epilepsy, have emerged from the reversal phenotype approach and the review of already published TTC5 cases. Microcephaly and facial dysmorphism resulted in being less variable than that documented before. The TTC5 clinical features have been compared with MKHK1 published cases in the hypothesis that clinical overlap in some characteristics of the two conditions was related to the common p300 molecular pathway.
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Deficiência Intelectual , Microcefalia , Éxons , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Masculino , Microcefalia/genética , Mutação , Fenótipo , Síndrome , Fatores de Transcrição/genéticaRESUMO
TAF8 is part of the transcription factor II D complex, composed of the TATA-binding protein and 13 TATA-binding protein-associated factors (TAFs). Transcription factor II D is the first general transcription factor recruited at promoters to assemble the RNA polymerase II preinitiation complex. So far disorders related to variants in 5 of the 13 subunits of human transcription factor II D have been described. Recently, a child with a homozygous c.781-1G>A mutation in TAF8 has been reported. Here we describe seven further patients with mutations in TAF8 and thereby confirm the TAF8 related disorder. In two sibling patients, we identified two novel compound heterozygous TAF8 splice site mutations, c.45+4A > G and c.489G>A, which cause aberrant splicing as well as reduced expression and mislocalization of TAF8. In five further patients, the previously described c.781-1G > A mutation was present on both alleles. The clinical phenotype associated with the different TAF8 mutations is characterized by severe psychomotor retardation with almost absent development, feeding problems, microcephaly, growth retardation, spasticity and epilepsy. Cerebral imaging showed hypomyelination, a thin corpus callosum and brain atrophy. Moreover, repeated imaging in the sibling pair demonstrated progressive cerebral and cerebellar atrophy. Consistently, reduced N-acetylaspartate, a marker of neuronal viability, was observed on magnetic resonance spectroscopy. Further review of the literature shows that mutations causing a reduced expression of transcription factor II D subunits have an overlapping phenotype of microcephaly, developmental delay and intellectual disability. Although transcription factor II D plays an important role in RNA polymerase II transcription in all cells and tissues, the symptoms associated with such defects are almost exclusively neurological. This might indicate a specific vulnerability of neuronal tissue to widespread deregulation of gene expression as also seen in Rett syndrome or Cornelia de Lange syndrome.
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Microcefalia , Doenças Neurodegenerativas , Fator de Transcrição TFIID , Atrofia/complicações , Criança , Humanos , Microcefalia/genética , Mutação , Doenças Neurodegenerativas/complicações , Fenótipo , RNA Polimerase II , Proteína de Ligação a TATA-Box/genética , Fator de Transcrição TFIID/genéticaRESUMO
JAG2 encodes the Notch ligand Jagged2. The conserved Notch signaling pathway contributes to the development and homeostasis of multiple tissues, including skeletal muscle. We studied an international cohort of 23 individuals with genetically unsolved muscular dystrophy from 13 unrelated families. Whole-exome sequencing identified rare homozygous or compound heterozygous JAG2 variants in all 13 families. The identified bi-allelic variants include 10 missense variants that disrupt highly conserved amino acids, a nonsense variant, two frameshift variants, an in-frame deletion, and a microdeletion encompassing JAG2. Onset of muscle weakness occurred from infancy to young adulthood. Serum creatine kinase (CK) levels were normal or mildly elevated. Muscle histology was primarily dystrophic. MRI of the lower extremities revealed a distinct, slightly asymmetric pattern of muscle involvement with cores of preserved and affected muscles in quadriceps and tibialis anterior, in some cases resembling patterns seen in POGLUT1-associated muscular dystrophy. Transcriptome analysis of muscle tissue from two participants suggested misregulation of genes involved in myogenesis, including PAX7. In complementary studies, Jag2 downregulation in murine myoblasts led to downregulation of multiple components of the Notch pathway, including Megf10. Investigations in Drosophila suggested an interaction between Serrate and Drpr, the fly orthologs of JAG1/JAG2 and MEGF10, respectively. In silico analysis predicted that many Jagged2 missense variants are associated with structural changes and protein misfolding. In summary, we describe a muscular dystrophy associated with pathogenic variants in JAG2 and evidence suggests a disease mechanism related to Notch pathway dysfunction.
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Proteína Jagged-2/genética , Distrofias Musculares/genética , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Linhagem Celular , Criança , Pré-Escolar , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Feminino , Glucosiltransferases/genética , Haplótipos/genética , Humanos , Proteína Jagged-1/genética , Proteína Jagged-2/química , Proteína Jagged-2/deficiência , Proteína Jagged-2/metabolismo , Masculino , Proteínas de Membrana/genética , Camundongos , Pessoa de Meia-Idade , Modelos Moleculares , Músculos/metabolismo , Músculos/patologia , Distrofias Musculares/patologia , Mioblastos/metabolismo , Mioblastos/patologia , Linhagem , Fenótipo , Receptores Notch/metabolismo , Transdução de Sinais , Sequenciamento do Exoma , Adulto JovemRESUMO
BACKGROUND: The relationship between thrombophilia genes and recurrent pregnancy loss has been discussed. The aim of this study was to investigate the association between of MTHFR C677T, A1298C, F2G20210A, and F5 G1691A genetic variants among Iranian women with recurrent miscarriage. METHODS: A total of 245 women with two or more recurrent pregnancy loss, with mean age years were enrolled in the study. To compare genotypes, we have selected 250 healthy women without history of miscarriage as control group. Genomic DNA of participants was evaluated using polymerase chain reaction followed by Sanger sequencing to determine the genotype frequency. RESULTS: The mean age were 32.16 ± (21-42) and 31.81 ± (19-40) for case and control groups respectively. MTHFR C677T and A1298C mutant alleles were found to be significantly more prevalent in patients than control. However, F2G20210A and F5 G1691A genetic variants showed no significance. CONCLUSION: The allele frequencies for the assessed genotypes in this study are consistent with the data obtained for other countries. We observed significant susceptible effects of MTHFR C677T, and A1298C among participants. According to the relatively high prevalence of these variants, we recommend genetic testing for women with RPL before therapeutic decisions.
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Aborto Habitual/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Mutação/genética , Trombofilia/genética , Aborto Habitual/epidemiologia , Adulto , Alelos , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Irã (Geográfico) , Reação em Cadeia da Polimerase , Polimorfismo Genético , Gravidez , Trombofilia/complicaçõesRESUMO
OBJECTIVES: Niemann-Pick diseases (NPD) is an autosomal recessive inherited lysosomal lipid storage disorder which occurs due to a defect in cellular cholesterol trafficking, leading to excess lipid accumulation in multiple organ systems such as the brain, lungs, spleen, and liver. SPMD1-associated disease includes classic infantile and visceral NPD type A and B respectively. Type C NPD is subacute or juvenile. MATERIALS & METHODS: During 2012-2016, the patients who had the clinical and biochemical signs and symptoms of different types of NPD, underwent genetic analysis. All patients were collected from five provinces in Iran (Razavi Khorasan, South Khorasan, Khozaestan, Isfahan and Tehran province). Sanger sequencing of the candidate genes for NPD was performed followed by bioinformatics analysis to confirm the types of NPD and to identify novel mutations. All patients underwent full clinical assessment. RESULTS: We present two cases with NPD type A, six cases with NPD type B, and 11 cases with type C with various enzymatic defects identified in these cases. Within these 19 patients, we present 9 previously reported mutations and 10 novel mutations causing NPD. CONCLUSION: This study is the largest Iranian study for NPD analysis ever. Our report demonstrates that NPD has a variable age of onset and can present early in life. We investigated the clinical and genetic manifestations of a large Iranian cohort. Understanding the variable presentation of NPD will allow for clinicians to have a high index of suspicion for the disease.
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OBJECTIVES: Mutation analysis of the Epidermal Growth Factor Receptor downstream has been a main part of colorectal carcinoma evaluation. Large prospective clinical trials have shown only colorectal cancer (CRC) with wild-type KRAS and NRAS responds to anti-Epidermal Growth Factor Receptor treatment. Hence, mutation analysis is necessary prior to treatment. It is essential to conduct studies to learn about the mutation signature of such tumors. The aim of this study was to evaluate the frequency of hotspot mutations in KRAS and NRAS genes in Iranian CRC patients and to explore their correlations with clinicopathologic parameters. METHODS: We detected mutations in exon 2 (codons 12 and 13) of the KRAS and NRAS genes using high resolution melting analysis, Intplex design and Sanger sequencing in 87 Iranian CRC patients. Genomic DNA was isolated from fresh tissue samples of CRC patients. RESULTS: From 87 eligible cases, 51 were male and 36 were females. KRAS mutations in codons 12 and 13 were present in 28.7% of all analyzed CRCs. Our findings suggested that the tumors with KRAS mutations are not with well- and moderately differentiated tumors compared to poorly differentiated tumors (P value = 0.32). The most frequent types of mutations were glycine to aspartate on codon 12 (p.G12D), and glycine to aspartate on codon 13 (p.G13D). No mutation was found in the NRAS gene in our patients. CONCLUSIONS: Based on this study, the frequency of KRAS mutations seems to be in the spectrum of frequencies of other countries such as China, Japan, India, USA, France, and Germany and NRAS was similar to the West of Iran.
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Neoplasias Colorretais/genética , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Análise Mutacional de DNA , Feminino , Seguimentos , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
OBJECTIVE: To compare the efficacy and functional outcome of Glasgow Coma Scale (GCS) score with that of Acute Physiology and Chronic Health Evaluation Score II (APACHE II) in patients with multiple trauma admitted to the ICU. METHODS: This cross-sectional study included 125 patients with traumatic brain injury associated with systemic trauma admitted to the ICU of Shahid Kamyab Hospital, Mashhad, between September 2015 and December 2016. On the day of admission, data were collected from each patient to calculate GCS and APACHE II scores. Sensitivity, specificity, and correct outcome prediction was compared between GCS and APACHE II. RESULTS: Positive predictive value (PPV) at the cut-off points was higher in APACHE II (80.6%) compared with GCS (69.2%). However, negative predictive value (NPV) of GCS was slightly higher in comparison with APACHE II. Moreover, the area under the receiver operating characteristic (ROC) curve for sensitivity and specificity of GCS and APACHE II showed no significant difference (0.81±0.04 vs. 0.83±0.04; p=0.278 respectively). CONCLUSION: Our study suggested that there was no considerable difference between GCS and APACHE II scores for predicting mortality in head injury patients. Both scales showed acceptable PPV, while APACHE II showed better results. However, the utilization of GCS in the initial assessment is recommended over APACHE II as the former provides higher time- and cost-efficiency.
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Doença da Deficiência de Múltiplas Sulfatases/complicações , Doença da Deficiência de Múltiplas Sulfatases/genética , Sulfatases/genética , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Oxirredutases atuantes sobre Doadores de Grupo Enxofre , Dermatopatias/etiologiaRESUMO
BACKGROUND: Joubert syndrome (JS) is a clinically and genetically heterogeneous group of rare neurodevelopmental disorder characterised by peculiar midbrain-hindbrain malformation, known as the "molar tooth" sign. JS can manifest a broad range of signs and symptoms. The most common features of JS are hypotonia, ataxia, developmental delay/intellectual disability, abnormal eye movements, and neonatal breathing abnormalities. To date, 29 genes have been shown to cause JS. METHODS: We employed whole-genome single nucleotide polymorphism genotyping in a group of Iranian families with JS and Sanger sequencing of a known mutation associated with JS located in a single homozygous regions shared by affected members of the families. RESULTS: Homozygosity mapping uncovered a shared â¼2.2-Mb run of homozygosity on chromosome 8q21.3-q22.1 encompassing the known JS-causing TMEM67 gene. Sanger sequencing of a known mutation (NM_153704.5: c.725A>G; p.Asn242Ser) in TMEM67 identified from studying another Iranian family using whole-exome sequencing confirmed the presence of the homozygous mutation in 22 affected members of 12 nuclear families. "Molar tooth" sign of brain magnetic resonance imaging, moderate-to-severe neurodevelopmental delay, and abnormal eye movements were the most common features of affected individuals. In addition, liver disease, seizure, behavioural abnormalities, failure to thrive, and kidney disease were observed variably in some of the patients. CONCLUSION: We propose that Asn242Ser is a founder mutation in the Iranian population, which might explain a significant proportion of JS cases from eastern Iran. Therefore, screening for this variant should be considered for genetic testing in Iranian patients with JS. In addition, this finding is important for developing population-specific genetic testing in Iran.
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Anormalidades Múltiplas/genética , Cerebelo/anormalidades , Anormalidades do Olho/genética , Efeito Fundador , Doenças Renais Císticas/genética , Proteínas de Membrana/genética , Mutação/genética , Retina/anormalidades , Insuficiência de Crescimento/genética , Feminino , Testes Genéticos , Estudo de Associação Genômica Ampla , Homozigoto , Humanos , Irã (Geográfico) , Hepatopatias/genética , Imageamento por Ressonância Magnética , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único/genética , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVE: The assessment of human epidermal growth factor receptor 2 (HER2) status has become of great importance in the diagnosis of breast cancer. The aim of this study was to investigate the diagnostic value of quantitative Polymerase Chain Reaction (qPCR) and Chromogenic In Situ Hybridization (CISH) to assess HER2 status of biopsy specimens. METHODS: To elucidate the status of HER2 gene amplification, biopsies of breast carcinoma from 120 patients with 2+ IHC status were analyzed by qPCR and CISH. RESULTS: The results of the two experiments were compared, and it was depicted that the concordance rate between CISH and qPCR assays was 88.1%.The quantification of HER2 gene with CISH and qPCR showed that there was a significant correlation (p value= 0.0001 and r= 0.808). CONCLUSION: The results of this research support the idea that qPCR is a precise and reproducible technique, which can be employed as a supplementary method to evaluate HER2 status.
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The DNA repair gene O6-methylguanine-DNA methyltransferase (MGMT) is frequently methylated in colorectal cancer (CRC). The aim of this study was to demonstrate that MGMT methylation may be one of the candidate mediators of field cancerization in the colon mucosa. Therefore, quantitative methylation-specific polymerase chain reaction was performed on tumor itself and additional samples of 5 and 10 cm away from the tumor in 40 CRC patients. Moreover, colon mucosa was examined from 30 cases with no evidence of cancer as a control. MGMT promoter methylation was present in 27.5% of colorectal tumor specimens. Tumors that showed MGMT promoter methylation had substantial MGMT promoter methylation in their normal adjacent mucosa. The methylation was also observed in 36.36% (4/11) of normal samples with MGMT promoter methylation in the adjacent tumors, in 20.79% (6/29) of samples without MGMT methylation in the adjacent tumors, and in 6.66% (2/30) of control samples (p<0.006 and p<0.001 respectively). Finally, the mean of MGMT methylation levels was significantly higher in the cancerous group than in the control group (6.25±1.702 vs. 0.086±0.036, p<0.001). Some CRCs arise from a field defect defined by epigenetic inactivation of MGMT. Detection of such abnormality may ultimately be useful in risk assessment for CRCs.