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1.
Am J Hum Genet ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39265574

RESUMEN

We previously identified a homozygous Alu insertion variant (Alu_Ins) in the 3'-untranslated region (3'-UTR) of SPINK1 as the cause of severe infantile isolated exocrine pancreatic insufficiency. Although we established that Alu_Ins leads to the complete loss of SPINK1 mRNA expression, the precise mechanisms remained elusive. Here, we aimed to elucidate these mechanisms through a hypothesis-driven approach. Initially, we speculated that, owing to its particular location, Alu_Ins could independently disrupt mRNA 3' end formation and/or affect other post-transcriptional processes such as nuclear export and translation. However, employing a 3'-UTR luciferase reporter assay, Alu_Ins was found to result in only an ∼50% reduction in luciferase activity compared to wild type, which is insufficient to account for the severe pancreatic deficiency in the Alu_Ins homozygote. We then postulated that double-stranded RNA (dsRNA) structures formed between Alu elements, an upstream mechanism regulating gene expression, might be responsible. Using RepeatMasker, we identified two Alu elements within SPINK1's third intron, both oriented oppositely to Alu_Ins. Through RNAfold predictions and full-length gene expression assays, we investigated orientation-dependent interactions between these Alu repeats. We provide compelling evidence to link the detrimental effect of Alu_Ins to extensive dsRNA structures formed between Alu_Ins and pre-existing intronic Alu sequences, including the restoration of SPINK1 mRNA expression by aligning all three Alu elements in the same orientation. Given the widespread presence of Alu elements in the human genome and the potential for new Alu insertions at almost any locus, our findings have important implications for detecting and interpreting Alu insertions in disease genes.

2.
Int J Mol Sci ; 25(17)2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39273547

RESUMEN

Just over thirty years is the span of a generation. It is also the time that has passed since the discovery of the gene responsible for cystic fibrosis. Today, it is safe to say that this discovery has revolutionized our understanding, research perspectives, and management of this disease, which was, thirty years ago, a pediatric condition with a grim prognosis. The aim of this review is to present the advances that science and medicine have brought to our understanding of the pathophysiology of the disease and its management, which in many ways, epitomizes modern molecular genetic research. Since the discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 1989, modeling the CFTR protein, deciphering its function as an ion channel, and identifying its molecular partners have led to numerous therapeutic advances. The most significant advancement in this field has been the discovery of protein modulators that can target its membrane localization and chloride channel activity. However, further progress is needed to ensure that all patients can benefit from a therapy tailored to their mutations, with the primary challenge being the development of treatments for mutations leading to a complete absence of the protein. The present review delves into the history of the multifaceted world of CF, covering main historical facts, current landscape, clinical management, emerging therapies, patient perspectives, and the importance of ongoing research, bridging science and medicine in the fight against the disease.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Fibrosis Quística/terapia , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Humanos , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Mutación , Animales
3.
Adv Sci (Weinh) ; : e2402550, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39119875

RESUMEN

Chronic pancreatitis (CP) is a complex disease with genetic and environmental factors at play. Through trio exome sequencing, a de novo SEC16A frameshift variant in a Chinese teenage CP patient is identified. Subsequent targeted next-generation sequencing of the SEC16A gene in 1,061 Chinese CP patients and 1,196 controls reveals a higher allele frequency of rare nonsynonymous SEC16A variants in patients (4.90% vs 2.93%; odds ratio [OR], 1.71; 95% confidence interval [CI], 1.26-2.33). Similar enrichments are noted in a French cohort (OR, 2.74; 95% CI, 1.67-4.50) and in a biobank meta-analysis (OR, 1.16; 95% CI, 1.04-1.31). Notably, Chinese CP patients with SEC16A variants exhibit a median onset age 5 years earlier than those without (40.0 vs 45.0; p = 0.012). Functional studies using three CRISPR/Cas9-edited HEK293T cell lines show that loss-of-function SEC16A variants disrupt coat protein complex II (COPII) formation, impede secretory protein vesicles trafficking, and induce endoplasmic reticulum (ER) stress due to protein overload. Sec16a+/- mice, which demonstrate impaired zymogen secretion and exacerbated ER stress compared to Sec16a+/+, are further generated. In cerulein-stimulated pancreatitis models, Sec16a+/- mice display heightened pancreatic inflammation and fibrosis compared to wild-type mice. These findings implicate a novel pathogenic mechanism predisposing to CP.

4.
Nat Commun ; 15(1): 6710, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39112481

RESUMEN

The demographical history of France remains largely understudied despite its central role toward understanding modern population structure across Western Europe. Here, by exploring publicly available Europe-wide genotype datasets together with the genomes of 3234 present-day and six newly sequenced medieval individuals from Northern France, we found extensive fine-scale population structure across Brittany and the downstream Loire basin and increased population differentiation between the northern and southern sides of the river Loire, associated with higher proportions of steppe vs. Neolithic-related ancestry. We also found increased allele sharing between individuals from Western Brittany and those associated with the Bell Beaker complex. Our results emphasise the need for investigating local populations to better understand the distribution of rare (putatively deleterious) variants across space and the importance of common genetic legacy in understanding the sharing of disease-related alleles between Brittany and people from western Britain and Ireland.


Asunto(s)
Genética de Población , Humanos , Francia , Genoma Humano/genética , Demografía , Variación Genética , Alelos , Genotipo , Historia Medieval , Europa (Continente)
5.
HGG Adv ; 5(4): 100335, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39039793

RESUMEN

Heterozygous mutations in SLC40A1, encoding a multi-pass membrane protein of the major facilitator superfamily known as ferroportin 1 (FPN1), are responsible for two distinct hereditary iron-overload diseases: ferroportin disease, which is associated with reduced FPN1 activity (i.e., decrease in cellular iron export), and SLC40A1-related hemochromatosis, which is associated with abnormally high FPN1 activity (i.e., resistance to hepcidin). Here, we report three SLC40A1 missense variants with opposite functional consequences. In cultured cells, the p.Arg40Gln and p.Ser47Phe substitutions partially reduced the ability of FPN1 to export iron and also partially reduced its sensitivity to hepcidin. The p.Ala350Val substitution had more profound effects, resulting in low FPN1 iron egress and weak FPN1/hepcidin interaction. Structural analyses helped to differentiate the first two substitutions, which are predicted to cause local instabilities, and the third, which is thought to prevent critical rigid-body movements that are essential to the iron transport cycle. The phenotypic traits observed in a total of 12 affected individuals are highly suggestive of ferroportin disease. Our findings dismantle the classical dualism of FPN1 loss versus gain of function, highlight some specific and unexpected functions of FPN1 transmembrane helices in the molecular mechanism of iron export and its regulation by hepcidin, and extend the spectrum of rare genetic variants that may cause ferroportin disease.

6.
Clin Res Hepatol Gastroenterol ; 48(6): 102346, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38657903

RESUMEN

Genetic testing is performed for unexplained pancreatitis. The aim of this study was to evaluate the diagnostic value of repeating genetic testing in idiopathic pancreatitis when new predisposing genes are identified. We investigated 330 patients who were initially screened for PRSS1, SPINK1 and CFTR genes. A new analysis was performed by Next-Generation Sequencing (NGS) for PRSS1, SPINK1, CFTR, CTRC, CASR, CPA1, TRPV6 genes and the CEL-HYB1 allele in clinical practice, and patients were included in our cohort study. Additional rare variants were identified in 7.3 % of the patients. Screening for new pancreatitis genes is recommended when initial screening is limited. Routine use of NGS is a useful diagnostic tool in these cases.


Asunto(s)
Pruebas Genéticas , Pancreatitis Crónica , Humanos , Pancreatitis Crónica/genética , Pancreatitis Crónica/diagnóstico , Femenino , Masculino , Persona de Mediana Edad , Adulto , Secuenciación de Nucleótidos de Alto Rendimiento , Anciano , Estudios de Cohortes , Inhibidor de Tripsina Pancreática de Kazal/genética , Tripsina
8.
Hum Genomics ; 18(1): 21, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38414044

RESUMEN

BACKGROUND: Single-nucleotide variants (SNVs) within gene coding sequences can significantly impact pre-mRNA splicing, bearing profound implications for pathogenic mechanisms and precision medicine. In this study, we aim to harness the well-established full-length gene splicing assay (FLGSA) in conjunction with SpliceAI to prospectively interpret the splicing effects of all potential coding SNVs within the four-exon SPINK1 gene, a gene associated with chronic pancreatitis. RESULTS: Our study began with a retrospective analysis of 27 SPINK1 coding SNVs previously assessed using FLGSA, proceeded with a prospective analysis of 35 new FLGSA-tested SPINK1 coding SNVs, followed by data extrapolation, and ended with further validation. In total, we analyzed 67 SPINK1 coding SNVs, which account for 9.3% of the 720 possible coding SNVs. Among these 67 FLGSA-analyzed SNVs, 12 were found to impact splicing. Through detailed comparison of FLGSA results and SpliceAI predictions, we inferred that the remaining 653 untested coding SNVs in the SPINK1 gene are unlikely to significantly affect splicing. Of the 12 splice-altering events, nine produced both normally spliced and aberrantly spliced transcripts, while the remaining three only generated aberrantly spliced transcripts. These splice-impacting SNVs were found solely in exons 1 and 2, notably at the first and/or last coding nucleotides of these exons. Among the 12 splice-altering events, 11 were missense variants (2.17% of 506 potential missense variants), and one was synonymous (0.61% of 164 potential synonymous variants). Notably, adjusting the SpliceAI cut-off to 0.30 instead of the conventional 0.20 would improve specificity without reducing sensitivity. CONCLUSIONS: By integrating FLGSA with SpliceAI, we have determined that less than 2% (1.67%) of all possible coding SNVs in SPINK1 significantly influence splicing outcomes. Our findings emphasize the critical importance of conducting splicing analysis within the broader genomic sequence context of the study gene and highlight the inherent uncertainties associated with intermediate SpliceAI scores (0.20 to 0.80). This study contributes to the field by being the first to prospectively interpret all potential coding SNVs in a disease-associated gene with a high degree of accuracy, representing a meaningful attempt at shifting from retrospective to prospective variant analysis in the era of exome and genome sequencing.


Asunto(s)
Empalme del ARN , Inhibidor de Tripsina Pancreática de Kazal , Humanos , Inhibidor de Tripsina Pancreática de Kazal/genética , Estudios Retrospectivos , Empalme del ARN/genética , Exones/genética , Secuencia de Bases , Empalme Alternativo/genética
9.
Cells ; 13(2)2024 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-38247876

RESUMEN

Cystic Fibrosis (CF) is present due to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, the most frequent variant being p.phe508del. The CFTR protein is a chloride (Cl-) channel which is defective and almost absent of cell membranes when the p.Phe508del mutation is present. The p.Phe508del-CFTR protein is retained in the endoplasmic reticulum (ER) and together with inflammation and infection triggers the Unfolded Protein Response (UPR). During the UPR, the Activating Transcription Factor 6 (ATF6) is activated with cleavage and then decreases the expression of p.Phe508del-CFTR. We have previously shown that the inhibition of the activation of ATF6 alleviates the p.Phe508del-CFTR defects in cells overexpressing the mutated protein. In the present paper, our aim was to inhibit the cleavage of ATF6, and thus its activation in a human bronchial cell line with endogenous p.Phe508del-CFTR expression and in bronchial cells from patients, to be more relevant to CF. This was achieved by inhibiting the protease MBTP1 which is responsible for the cleavage of ATF6. We show here that this inhibition leads to increased mRNA and p.Phe508del-CFTR expression and, consequently, to increased Cl-efflux. We also explain the mechanisms linked to these increases with the modulation of genes when MBTP1 is inhibited. Indeed, RT-qPCR assays show that genes such as HSPA1B, CEBPB, VIMP, PFND2, MAPK8, XBP1, INSIG1, and CALR are modulated. In conclusion, we show that the inhibition of MBTP1 has a beneficial effect in relevant models to CF and that this is due to the modulation of genes involved in the disease.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Proproteína Convertasas , Humanos , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Fibrosis Quística/genética , Factores de Transcripción , Serina Endopeptidasas
10.
Am J Med Genet A ; 194(5): e63532, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38192009

RESUMEN

Alpha-mannosidosis is a rare autosomal recessive lysosomal storage disorder caused by biallelic mutations in the MAN2B1 gene and characterized by a wide clinical heterogeneity. Diagnosis for this multisystemic disorder is confirmed by the presence of either a deficiency in the lysosomal enzyme acid alpha-mannosidase or biallelic mutations in the MAN2B1 gene. This diagnosis confirmation is crucial for both clinical management and genetic counseling purposes. Here we describe a late diagnosis of alpha-mannosidosis in a patient presenting with syndromic intellectual disability, and a rare retinopathy, where reverse phenotyping played a pivotal role in interpreting the exome sequencing result. While a first missense variant was classified as a variant of uncertain significance, the phenotype-guided analysis helped us detect and interpret an in-trans apparent alu-element insertion, which appeared to be a copy number variant (CNV) not identified by the CNV caller. A biochemical analysis showing abnormal excretion of urinary mannosyloligosaccharide and an enzyme assay permitted the re-classification of the missense variant to likely pathogenic, establishing the diagnosis of alpha-mannosidosis. This work emphasizes the importance of reverse phenotyping in the context of exome sequencing.


Asunto(s)
alfa-Manosidosis , Humanos , alfa-Manosidosis/diagnóstico , alfa-Manosidosis/genética , Variaciones en el Número de Copia de ADN/genética , alfa-Manosidasa/genética , Mutación Missense/genética , Fenotipo
11.
Genet Med ; 26(5): 101087, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38288683

RESUMEN

PURPOSE: Interneuronopathies are a group of neurodevelopmental disorders characterized by deficient migration and differentiation of gamma-aminobutyric acidergic interneurons resulting in a broad clinical spectrum, including autism spectrum disorders, early-onset epileptic encephalopathy, intellectual disability, and schizophrenic disorders. SP9 is a transcription factor belonging to the Krüppel-like factor and specificity protein family, the members of which harbor highly conserved DNA-binding domains. SP9 plays a central role in interneuron development and tangential migration, but it has not yet been implicated in a human neurodevelopmental disorder. METHODS: Cases with SP9 variants were collected through international data-sharing networks. To address the specific impact of SP9 variants, in silico and in vitro assays were carried out. RESULTS: De novo heterozygous variants in SP9 cause a novel form of interneuronopathy. SP9 missense variants affecting the glutamate 378 amino acid result in severe epileptic encephalopathy because of hypomorphic and neomorphic DNA-binding effects, whereas SP9 loss-of-function variants result in a milder phenotype with epilepsy, developmental delay, and autism spectrum disorder. CONCLUSION: De novo heterozygous SP9 variants are responsible for a neurodevelopmental disease. Interestingly, variants located in conserved DNA-binding domains of KLF/SP family transcription factors may lead to neomorphic DNA-binding functions resulting in a combination of loss- and gain-of-function effects.


Asunto(s)
Trastorno del Espectro Autista , Epilepsia , Discapacidad Intelectual , Interneuronas , Factores de Transcripción Sp , Factores de Transcripción , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Trastorno del Espectro Autista/genética , Trastorno del Espectro Autista/patología , Epilepsia/genética , Epilepsia/patología , Heterocigoto , Discapacidad Intelectual/genética , Discapacidad Intelectual/patología , Interneuronas/metabolismo , Interneuronas/patología , Mutación Missense/genética , Trastornos del Neurodesarrollo/genética , Trastornos del Neurodesarrollo/patología , Fenotipo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Factores de Transcripción Sp/genética
12.
Pancreatology ; 23(8): 957-963, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37949771

RESUMEN

BACKGROUND: Genetic predisposition is crucial in the pathogenesis of early-onset chronic pancreatitis (CP). So far, several genetic alterations have been identified as risk factors, predominantly in genes encoding digestive enzymes. However, many early-onset CP cases have no identified underlying cause. Chymotrypsins are a family of serine proteases that can cleave trypsinogen and lead to its degradation. Because genetic alterations in the chymotrypsins CTRC, CTRB1, and CTRB2 are associated with CP, we genetically and functionally investigated chymotrypsin-like protease (CTRL) as a potential risk factor. METHODS: We screened 1005 non-alcoholic CP patients and 1594 controls for CTRL variants by exome sequencing. We performed Western blots and activity assays to analyse secretion and proteolytic activity. We measured BiP mRNA expression to investigate the potential impact of identified alterations on endoplasmic reticulum (ER) stress. RESULTS: We identified 13 heterozygous non-synonymous CTRL variants: five exclusively in patients and three only in controls. Functionality was unchanged in 6/13 variants. Four alterations showed normal secretion but reduced (p.G20S, p.G56S, p.G61S) or abolished (p.S208F) activity. Another three variants (p.C201Y, p.G215R and p.C220G) were not secreted and already showed reduced or no activity intracellularly. However, intracellular retention did not lead to ER stress. CONCLUSION: We identified several CTRL variants, some showing potent effects on protease function and secretion. We observed these effects in variants found in patients and controls, and CTRL loss-of-function variants were not significantly more common in patients than controls. Therefore, CTRL is unlikely to play a relevant role in the development of CP.


Asunto(s)
Quimasas , Pancreatitis Crónica , Humanos , Quimasas/genética , Predisposición Genética a la Enfermedad , Mutación , Pancreatitis Crónica/genética , Pancreatitis Crónica/metabolismo , Factores de Riesgo
13.
Pancreatology ; 23(5): 491-506, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37581535

RESUMEN

BACKGROUND: PRSS1 was the first reported chronic pancreatitis (CP) gene. The existence of both gain-of-function (GoF) and gain-of-proteotoxicity (GoP) pathological PRSS1 variants, together with the fact that PRSS1 variants have been identified in CP subtypes spanning the range from monogenic to multifactorial, has made the classification of PRSS1 variants very challenging. METHODS: All currently reported PRSS1 variants (derived primarily from two databases) were manually reviewed with respect to their clinical genetics, functional analysis and population allele frequency. They were classified by variant type and pathological mechanism within the framework of our recently proposed ACMG/AMP guidelines-based seven-category system. RESULTS: The total number of distinct germline PRSS1 variants included for analysis was 100, comprising 3 copy number variants (CNVs), 12 5' and 3' variants, 19 intronic variants, 5 nonsense variants, 1 frameshift deletion variant, 6 synonymous variants, 1 in-frame duplication, 3 gene conversions and 50 missense variants. Based upon a combination of clinical genetic and functional analysis, population data and in silico analysis, we classified 26 variants (all 3 CNVs, the in-frame duplication, all 3 gene conversions and 19 missense) as "pathogenic", 3 variants (missense) as "likely pathogenic", 5 variants (four missense and one promoter) as "predisposing", 13 variants (all missense) as "unknown significance", 2 variants (missense) as "likely benign", and all remaining 51 variants as "benign". CONCLUSIONS: We describe an expert classification of the 100 PRSS1 variants reported to date. The results have immediate implications for reclassifying many ClinVar-registered PRSS1 variants as well as providing optimal guidelines/standards for reporting PRSS1 variants.


Asunto(s)
Pueblos del Este de Asia , Pancreatitis Crónica , Humanos , Alelos , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Mutación/genética , Pancreatitis Crónica/genética , Pancreatitis Crónica/patología , Tripsina/genética , Tripsinógeno/genética , China , Francia
14.
Int J Mol Sci ; 24(13)2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37445855

RESUMEN

More than 2000 variations are described within the CFTR (Cystic Fibrosis Transmembrane Regulator) gene and related to large clinical issues from cystic fibrosis to mono-organ diseases. Although these CFTR-associated diseases have been well documented, a large phenotype spectrum is observed and correlations between phenotypes and genotypes are still not well established. To address this issue, we present several regulatory elements that can modulate CFTR gene expression in a tissue-specific manner. Among them, cis-regulatory elements act through chromatin loopings and take part in three-dimensional structured organization. With tissue-specific transcription factors, they form chromatin modules and can regulate gene expression. Alterations of specific regulations can impact and modulate disease expressions. Understanding all those mechanisms highlights the need to expand research outside the gene to enhance our knowledge.


Asunto(s)
Fibrosis Quística , Humanos , Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Factores de Transcripción/metabolismo , Expresión Génica , Cromatina , Regulación de la Expresión Génica
15.
Pancreatology ; 23(5): 507-511, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37270400

RESUMEN

Mutations in the PNLIP gene have recently been implicated in chronic pancreatitis. Several PNLIP missense variants have been reported to cause protein misfolding and endoplasmic reticulum stress although genetic evidence supporting their association with chronic pancreatitis is currently lacking. Protease-sensitive PNLIP missense variants have also been associated with early-onset chronic pancreatitis although the underlying pathological mechanism remains enigmatic. Herein, we provide new evidence to support the association of protease-sensitive PNLIP variants (but not misfolding PNLIP variants) with pancreatitis. Specifically, we identified protease-sensitive PNLIP variants in 5 of 373 probands (1.3%) with a positive family history of pancreatitis. The protease-sensitive variants, p.F300L and p.I265R, were found to segregate with the disease in three families, including one exhibiting a classical autosomal dominant inheritance pattern. Consistent with previous findings, protease-sensitive variant-positive patients were often characterized by early-onset disease and invariably experienced recurrent acute pancreatitis, although none has so far developed chronic pancreatitis.


Asunto(s)
Lipasa , Pancreatitis Crónica , Péptido Hidrolasas , Humanos , Enfermedad Aguda , Mutación , Pancreatitis Crónica/genética , Pancreatitis Crónica/metabolismo , Péptido Hidrolasas/genética , Lipasa/genética
16.
PLoS One ; 18(4): e0280976, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37093806

RESUMEN

Non-invasive prenatal diagnosis of single-gene disorders (SGD-NIPD) has been widely accepted, but is mostly limited to the exclusion of either paternal or de novo mutations. Indeed, it is still difficult to infer the inheritance of the maternal allele from cell-free DNA (cfDNA) analysis. Based on the study of maternal haplotype imbalance in cfDNA, relative haplotype dosage (RHDO) was developed to address this challenge. Although RHDO has been shown to be reliable, robust control of statistical error and explicit delineation of critical parameters for assessing the quality of the analysis have not been fully addressed. We present here a universal and adaptable enhanced-RHDO (eRHDO) procedure through an automated bioinformatics pipeline with a didactic visualization of the results, aiming to be applied for any SGD-NIPD in routine care. A training cohort of 43 families carrying CFTR, NF1, DMD, or F8 mutations allowed the characterization and optimal setting of several adjustable data variables, such as minimum sequencing depth, type 1 and type 2 statistical errors, as well as the quality assessment of intermediate steps and final results by block score and concordance score. Validation was successfully performed on a test cohort of 56 pregnancies. Finally, computer simulations were used to estimate the effect of fetal-fraction, sequencing depth and number of informative SNPs on the quality of results. Our workflow proved to be robust, as we obtained conclusive and correctly inferred fetal genotypes in 94.9% of cases, with no false-negative or false-positive results. By standardizing data generation and analysis, we fully describe a turnkey protocol for laboratories wishing to offer eRHDO-based non-invasive prenatal diagnosis for single-gene disorders as an alternative to conventional prenatal diagnosis.


Asunto(s)
Ácidos Nucleicos Libres de Células , Pruebas Prenatales no Invasivas , Embarazo , Femenino , Humanos , Haplotipos , Pruebas Prenatales no Invasivas/métodos , Diagnóstico Prenatal/métodos , Genotipo
18.
Blood Transfus ; 21(3): 209-217, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36346882

RESUMEN

BACKGROUND: Discriminating individuals with "Asian type DEL" from those who are "true D-negative" (D-) among serologically D- donors/patients in Asia would be very valuable, as clinical outcomes are different in these groups. Here we investigated the molecular basis of D-negativity in Thai blood donors, designing a specific strategy for this purpose. MATERIALS AND METHODS: After routine testing, a total of 1,270 serologically D- blood donors originating from Central, Northeastern and South Thailand underwent analysis of the RHD gene by (i) quantitative multiplex polymerase chain reaction of short fluorescent fragments (QMPSF); (ii) direct sequencing of exon 9 to identify the c.1227G>A variant defining the Asian type DEL allele; and (iii) direct sequencing of the other exons. RESULTS: The most common observation was whole deletion of the gene (i.e. RHD*01N.01; allele frequency: 86.81%), followed by the Asian type DEL allele (RHD*01EL.01; 7.60%) and a D-negative hybrid allele (RHD*01N.03; 3.46%). Four novel alleles, including one with a 13.1 kilobase-deletion, were identified and characterized. All but one RHD*01EL.01 allele carriers (183/184) were C-positive (C+), suggesting that this latter subset may be screened specifically when investigating the c.1227G>A variant, which can be identified with 100% accuracy by a specific Tm-shift genotyping assay. DISCUSSION: On the basis of our extensive molecular findings, we have designed a dedicated diagnostic strategy based on Rh C antigen typing followed by a genotyping test. Implementation of this method in all or selected groups of serologically D- donors/patients will contribute to improve the management of transfusion and pregnancy in Thailand.


Asunto(s)
Donantes de Sangre , Antígenos de Grupos Sanguíneos , Humanos , Fenotipo , Tailandia/epidemiología , Sistema del Grupo Sanguíneo Rh-Hr/genética , Reacción en Cadena de la Polimerasa Multiplex/métodos , Alelos , Genotipo
19.
Gastro Hep Adv ; 2(2): 186-195, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-39132611

RESUMEN

Background and Aims: Heavy alcohol consumption and genetic factors represent the 2 major etiologies of chronic pancreatitis (CP). However, little is so far known about the clinical features and genetic basis of light-to-moderate alcohol consumption-related CP (LMA-CP). Methods: A cross-sectional analysis was performed on 1061 Chinese CP patients between 2010 and 2015. CP was classified as classical alcoholic CP (ACP; n = 206), LMA-CP (n = 154), and idiopathic CP (ICP; n = 701). Clinical features and genetic characteristics (PRSS1, SPINK1, CTRC, CFTR variant status) were compared between the different groups. Odds ratios (ORs) with 95% confidence intervals were calculated to ascertain the combinatorial effect of alcohol consumption and gene mutation. Results: Compared with ICP, the clinical features of LMA-CP were characterized by higher rates of developing pancreatic stones, pseudocyst, diabetes, and steatorrhea, which were similar to those associated with ACP. The prevalence of CP-related gene variants in LMA-CP was 38.3%, similar to ACP (39.8%), although significantly lower than ICP (56.2%). Alcohol consumption enhanced the risk of a poor clinical outcome, whereas genetic factors amplified alcohol's effects. Compared with ICP, LMA-CP and ACP were associated with a high risk of pancreatic stones (patients without variants, OR = 2.01 and 2.54; patients with variants, OR = 2.17 and 1.07), pseudocyst (patients without variants, OR = 1.03 and 1.43; patients with variants, OR = 1.67 and 2.14), diabetes mellitus (patients without variants, OR = 0.86 and 1.31; patients with variants, OR = 2.05 and 1.55), and steatorrhea (patients without variants, OR = 1.56 and 2.10; patients with variants, OR = 2.11 and 1.60). Conclusion: Evidence was presented to show that LMA-CP was clinically and genetically similar to ACP but significantly different from ICP. Our findings provide support to the growing view that there is no safe level of alcohol consumption.

20.
Hum Mutat ; 43(12): 2308-2323, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36273432

RESUMEN

Modeling splicing is essential for tackling the challenge of variant interpretation as each nucleotide variation can be pathogenic by affecting pre-mRNA splicing via disruption/creation of splicing motifs such as 5'/3' splice sites, branch sites, or splicing regulatory elements. Unfortunately, most in silico tools focus on a specific type of splicing motif, which is why we developed the Splicing Prediction Pipeline (SPiP) to perform, in one single bioinformatic analysis based on a machine learning approach, a comprehensive assessment of the variant effect on different splicing motifs. We gathered a curated set of 4616 variants scattered all along the sequence of 227 genes, with their corresponding splicing studies. The Bayesian analysis provided us with the number of control variants, that is, variants without impact on splicing, to mimic the deluge of variants from high-throughput sequencing data. Results show that SPiP can deal with the diversity of splicing alterations, with 83.13% sensitivity and 99% specificity to detect spliceogenic variants. Overall performance as measured by area under the receiving operator curve was 0.986, better than SpliceAI and SQUIRLS (0.965 and 0.766) for the same data set. SPiP lends itself to a unique suite for comprehensive prediction of spliceogenicity in the genomic medicine era. SPiP is available at: https://sourceforge.net/projects/splicing-prediction-pipeline/.


Asunto(s)
Sitios de Empalme de ARN , Empalme del ARN , Humanos , Teorema de Bayes , Empalme del ARN/genética , Exones/genética , Sitios de Empalme de ARN/genética , Aprendizaje Automático , Intrones/genética
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