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1.
J Med Genet ; 61(7): 645-651, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38453479

RESUMEN

BACKGROUND: Studies indicate that variants of uncertain significance are more common in non-European populations due to lack of a diversity in population databases. This difference has not been explored in epilepsy, which is increasingly found to be genetic in paediatric populations, and has precision medicine applications. This study examines the differences in the frequency of uncertain next-generation sequencing (NGS) results among a paediatric epilepsy cohort between ancestral groups historically under-represented in biomedical research (UBR) and represented in biomedical research (RBR). METHODS: A retrospective chart review of patients with epilepsy seen at Columbia University Irving Medical Center (CUIMC). One hundred seventy-eight cases met the following criteria: (1) visited any provider within the Pediatric Neurology Clinic at CUIMC, (2) had an ICD code indicating a diagnosis of epilepsy, (3) underwent NGS testing after March 2015 and (4) had self-reported ancestry that fit into a single dichotomous category of either historically represented or under-represented in biomedical research. RESULTS: UBR cases had significantly higher rates of uncertain results when compared with RBR cases (79.2% UBR, 20.8% RBR; p value=0.002). This finding remained true after controlling for potential confounding factors, including sex, intellectual disability or developmental delay, epilepsy type, age of onset, number of genes tested and year of testing. CONCLUSION: Our results add to the literature that individuals who are of ancestries historically under-represented in genetics research are more likely to receive uncertain genetic results than those of represented majority ancestral groups and establishes this finding in an epilepsy cohort.


Asunto(s)
Epilepsia , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Epilepsia/genética , Masculino , Femenino , Niño , Adolescente , Preescolar , Variación Genética/genética , Estudios Retrospectivos , Estudios de Cohortes , Predisposición Genética a la Enfermedad , Lactante
2.
medRxiv ; 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38260255

RESUMEN

SPOUT1/CENP-32 encodes a putative SPOUT RNA methyltransferase previously identified as a mitotic chromosome associated protein. SPOUT1/CENP-32 depletion leads to centrosome detachment from the spindle poles and chromosome misalignment. Aided by gene matching platforms, we identified 24 individuals with neurodevelopmental delays from 18 families with bi-allelic variants in SPOUT1/CENP-32 detected by exome/genome sequencing. Zebrafish spout1/cenp-32 mutants showed reduction in larval head size with concomitant apoptosis likely associated with altered cell cycle progression. In vivo complementation assays in zebrafish indicated that SPOUT1/CENP-32 missense variants identified in humans are pathogenic. Crystal structure analysis of SPOUT1/CENP-32 revealed that most disease-associated missense variants mapped to the catalytic domain. Additionally, SPOUT1/CENP-32 recurrent missense variants had reduced methyltransferase activity in vitro and compromised centrosome tethering to the spindle poles in human cells. Thus, SPOUT1/CENP-32 pathogenic variants cause an autosomal recessive neurodevelopmental disorder: SpADMiSS ( SPOUT1 Associated Development delay Microcephaly Seizures Short stature) underpinned by mitotic spindle organization defects and consequent chromosome segregation errors.

3.
Genet Med ; 25(12): 100983, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37746849

RESUMEN

PURPOSE: Previous work identified rare variants in DSTYK associated with human congenital anomalies of the kidney and urinary tract (CAKUT). Here, we present a series of mouse and human studies to clarify the association, penetrance, and expressivity of DSTYK variants. METHODS: We phenotypically characterized Dstyk knockout mice of 3 separate inbred backgrounds and re-analyzed the original family segregating the DSTYK c.654+1G>A splice-site variant (referred to as "SSV" below). DSTYK loss of function (LOF) and SSVs were annotated in individuals with CAKUT, epilepsy, or amyotrophic lateral sclerosis vs controls. A phenome-wide association study analysis was also performed using United Kingdom Biobank (UKBB) data. RESULTS: Results demonstrate ∼20% to 25% penetrance of obstructive uropathy, at least, in C57BL/6J and FVB/NJ Dstyk-/- mice. Phenotypic penetrance increased to ∼40% in C3H/HeJ mutants, with mild-to-moderate severity. Re-analysis of the original family segregating the rare SSV showed low penetrance (43.8%) and no alternative genetic causes for CAKUT. LOF DSTYK variants burden showed significant excess for CAKUT and epilepsy vs controls and an exploratory phenome-wide association study supported association with neurological disorders. CONCLUSION: These data support causality for DSTYK LOF variants and highlights the need for large-scale sequencing studies (here >200,000 cases) to accurately assess causality for genes and variants to lowly penetrant traits with common population prevalence.


Asunto(s)
Epilepsia , Sistema Urinario , Anomalías Urogenitales , Animales , Ratones , Humanos , Penetrancia , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Anomalías Urogenitales/genética , Riñón/anomalías , Factores de Riesgo , Epilepsia/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética
4.
Sci Adv ; 9(10): eade1463, 2023 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-36897941

RESUMEN

Pathogenic variants in KMT5B, a lysine methyltransferase, are associated with global developmental delay, macrocephaly, autism, and congenital anomalies (OMIM# 617788). Given the relatively recent discovery of this disorder, it has not been fully characterized. Deep phenotyping of the largest (n = 43) patient cohort to date identified that hypotonia and congenital heart defects are prominent features that were previously not associated with this syndrome. Both missense variants and putative loss-of-function variants resulted in slow growth in patient-derived cell lines. KMT5B homozygous knockout mice were smaller in size than their wild-type littermates but did not have significantly smaller brains, suggesting relative macrocephaly, also noted as a prominent clinical feature. RNA sequencing of patient lymphoblasts and Kmt5b haploinsufficient mouse brains identified differentially expressed pathways associated with nervous system development and function including axon guidance signaling. Overall, we identified additional pathogenic variants and clinical features in KMT5B-related neurodevelopmental disorder and provide insights into the molecular mechanisms of the disorder using multiple model systems.


Asunto(s)
Megalencefalia , Trastornos del Neurodesarrollo , Animales , Humanos , Ratones , Haploinsuficiencia , Metiltransferasas/genética , Ratones Noqueados , Trastornos del Neurodesarrollo/genética , Fenotipo
5.
Epilepsia ; 64(4): 986-997, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36740579

RESUMEN

OBJECTIVE: Exome sequencing (ES) has played an important role in the identification of causative variants for individuals with epilepsy and has proven to be a valuable diagnostic tool. Less is known about its clinical utility once a diagnosis is received. This study systematically reviewed the impact of ES results on clinical decision-making and patient care in a pediatric epilepsy cohort at a tertiary care medical center. METHODS: Pediatric patients with unexplained epilepsy were referred by their neurologist, and informed consent was obtained through an institutional review board-approved research ES protocol. For patients who received a genetic diagnosis, a retrospective chart review was completed of the probands and their relatives' medical records prior to and after genetic diagnosis. The following outcomes were explored: provider management recommendations, changes in care actually implemented, and anticipatory guidance provided regarding the proband's condition. RESULTS: Fifty-three probands met the inclusion criteria. Genetic diagnosis led to at least one provider recommendation in 41.5% families (22/53). Recommendations were observed in the following categories: medication, screening for non-neurological comorbidities/referrals to specialists, referrals to clinical research/trials, and cascade testing. Anticipatory guidance including information about molecular diagnosis, prognosis, and relevant foundations/advocacy groups was also observed. SIGNIFICANCE: Results demonstrate the clinical utility of ES for individuals with epilepsy across multiple aspects of patient care, including anti-seizure medication (ASM) selection; screening for non-neurological comorbidities and referrals to appropriate medical specialists; referral to reproductive genetic counseling; and access to research, information, and support resources. To our knowledge, this is the first study to evaluate the clinical utility of ES for a pediatric epilepsy cohort with broad epilepsy phenotypes. This work supports the implementation of ES as part of clinical care in this population.


Asunto(s)
Epilepsia , Pruebas Genéticas , Humanos , Pruebas Genéticas/métodos , Estudios Retrospectivos , Secuenciación del Exoma , Epilepsia/diagnóstico , Epilepsia/genética , Fenotipo
6.
J Genet Couns ; 32(2): 266-280, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36281494

RESUMEN

Epilepsy, defined by the occurrence of two or more unprovoked seizures or one unprovoked seizure with a propensity for others, affects 0.64% of the population and can lead to significant morbidity and mortality. A majority of unexplained epilepsy (seizures not attributed to an acquired etiology, such as trauma or infection) is estimated to have an underlying genetic etiology. Despite rapid progress in understanding of the genetic underpinnings of the epilepsies, there are no recent evidence-based guidelines for genetic testing and counseling for this population. This practice guideline provides evidence-based recommendations for approaching genetic testing in the epilepsies using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence to Decision framework. We used evidence from a recent systematic evidence review and meta-analysis of diagnostic yield of genetic tests in patients with epilepsy. We also compiled data from other sources, including recently submitted conference abstracts and peer-reviewed journal articles. We identified and prioritized outcomes of genetic testing as critical, important or not important and based our recommendations on outcomes deemed critical and important. We considered the desirable and undesirable effects, value and acceptability to relevant stakeholders, impact on health equity, cost-effectiveness, certainty of evidence, and feasibility of the interventions in individuals with epilepsy. Taken together, we generated two clinical recommendations: (1) Genetic testing is strongly recommended for all individuals with unexplained epilepsy, without limitation of age, with exome/genome sequencing and/or a multi-gene panel (>25 genes) as first-tier testing followed by chromosomal microarray, with exome/genome sequencing conditionally recommended over multi-gene panel. (2) It is strongly recommended that genetic tests be selected, ordered, and interpreted by a qualified healthcare provider in the setting of appropriate pre-test and post-test genetic counseling. Incorporation of genetic counselors into neurology practices and/or referral to genetics specialists are both useful models for supporting providers without genetics expertise to implement these recommendations.


Asunto(s)
Consejeros , Epilepsia , Humanos , Pruebas Genéticas , Epilepsia/diagnóstico , Epilepsia/genética , Asesoramiento Genético , Práctica Clínica Basada en la Evidencia , Convulsiones , Consejo
7.
JAMA Netw Open ; 5(10): e2239122, 2022 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-36306130

RESUMEN

Importance: Diagnostic genetic testing can lead to changes in management in the pediatric intensive care unit. Genetic risk in children with critical illness but nondiagnostic exome sequencing (ES) has not been explored. Objective: To assess the association between loss-of-function (LOF) variants and pediatric critical illness. Design, Setting, and Participants: This genetic association study examined ES first screened for causative variants among 267 children at the Morgan Stanley Children's Hospital of NewYork-Presbyterian, of whom 22 were otherwise healthy with viral respiratory failure; 18 deceased children with bronchiolitis from the Office of the Chief Medical Examiner of New York City, of whom 14 were previously healthy; and 9990 controls from the Institute for Genomic Medicine at Columbia University Irving Medical Center. The ES data were generated between January 1, 2015, and December 31, 2020, and analyzed between January 1, 2017, and September 2, 2022. Exposure: Critical illness. Main Outcomes and Measures: Odds ratios and P values for genes and gene-sets enriched for rare LOF variants and the loss-of-function observed/expected upper bound fraction (LOEUF) score at which cases have a significant enrichment. Results: This study included 285 children with critical illness (median [range] age, 4.1 [0-18.9] years; 148 [52%] male) and 9990 controls. A total of 228 children (80%) did not receive a genetic diagnosis. After quality control (QC), 231 children harbored excess rare LOF variants in genes with a LOEUF score of 0.680 or less (intolerant genes) (P = 1.0 × 10-5). After QC, 176 children without a diagnosis harbored excess ultrarare LOF variants in intolerant genes but only in those without a known disease association (odds ratio, 1.8; 95% CI, 1.3-2.5). After QC, 25 children with viral respiratory failure harbored excess ultrarare LOF variants in intolerant genes but only in those without a known disease association (odds ratio, 2.8; 95% CI, 1.1-6.6). A total of 114 undiagnosed children were enriched for de novo LOF variants in genes without a known disease association (observed, 14; expected, 6.8; enrichment, 2.05). Conclusions and Relevance: In this genetic association study, excess LOF variants were observed among critically ill children despite nondiagnostic ES. Variants lay in genes without a known disease association, suggesting future investigation may connect phenotypes to causative genes.


Asunto(s)
Exoma , Insuficiencia Respiratoria , Masculino , Femenino , Humanos , Enfermedad Crítica , Estudios de Casos y Controles , Estudios de Asociación Genética
8.
Genet Med ; 24(4): 862-869, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35078725

RESUMEN

PURPOSE: The goal of stratified medicine is to identify subgroups of patients with similar disease mechanisms and specific responses to treatments. To prepare for stratified clinical trials, genome-wide genetic analysis should occur across clinical areas to identify undiagnosed genetic diseases and new genetic causes of disease. METHODS: To advance genetically stratified medicine, we have developed and implemented broad exome sequencing infrastructure and research protocols at Columbia University Irving Medical Center/NewYork-Presbyterian Hospital. RESULTS: We enrolled 4889 adult and pediatric probands and identified a primary result in 572 probands. The cohort was phenotypically and demographically heterogeneous because enrollment occurred across multiple specialty clinics (eg, epilepsy, nephrology, fetal anomaly). New gene-disease associations and phenotypic expansions were discovered across clinical specialties. CONCLUSION: Our study processes have enabled the enrollment and exome sequencing/analysis of a phenotypically and demographically diverse cohort of patients within 1 tertiary care medical center. Because all genomic data are stored centrally with permission for longitudinal access to the electronic medical record, subjects can be recontacted with updated genetic diagnoses or for participation in future genotype-based clinical trials. This infrastructure has allowed for the promotion of genetically stratified clinical trial readiness within the Columbia University Irving Medical Center/NewYork-Presbyterian Hospital health care system.


Asunto(s)
Pruebas Genéticas , Enfermedades no Diagnosticadas , Adulto , Niño , Pruebas Genéticas/métodos , Genómica , Humanos , Atención Terciaria de Salud , Secuenciación del Exoma/métodos
9.
BMC Neurol ; 21(1): 358, 2021 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-34530748

RESUMEN

BACKGROUND: Pathogenic variants in KDM5C are a cause of X-linked intellectual disability in males. Other features in males include short stature, dysmorphic features, seizures and spasticity. In some instances, female relatives were noted to have learning difficulties and mild intellectual disabilities, but full phenotypic descriptions were often incomplete. Recently, detailed phenotypic features of five affected females with de novo variants were described. (Clin Genet 98:43-55, 2020) Four individuals had a protein truncating variant and 1 individual had a missense variant. All five individuals had developmental delay/intellectual disability and three neurological features. CASE PRESENTATION: Here we report a three-year-old female with global developmental delay, hypotonia and ataxia. Through whole exome sequencing, a de novo c.1516A > G (p.Met506Val) variant in KDM5C was identified. This missense variant is in the jumonji-C domain of this multi domain protein where other missense variants have been previously reported in KDM5C related disorder. The KDM5C gene is highly intolerant to functional variation which suggests its pathogenicity. The probands motor delays and language impairment is consistent with other reported female patients with de novo variants in KDM5C. However, other features reported in females (distinctive facial features, skeletal abnormalities, short stature and endocrine features) were absent. To the best of our knowledge, our proband is the first female patient reported with a diagnosis of ataxia. CONCLUSIONS: This case report provides evidence for an emerging and phenotypic variability that adds to the literature of the role of KDM5C in females with neurodevelopmental disorders as well as movement disorders.


Asunto(s)
Discapacidades del Desarrollo , Discapacidad Intelectual , Ataxia , Niño , Preescolar , Discapacidades del Desarrollo/genética , Femenino , Histona Demetilasas , Humanos , Discapacidad Intelectual/genética , Masculino , Hipotonía Muscular , Fenotipo , Secuenciación del Exoma
10.
Am J Med Genet A ; 185(12): 3740-3753, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34331327

RESUMEN

Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome is caused by de novo loss-of-function variants in the SON gene (MIM #617140). This multisystemic disorder is characterized by intellectual disability, seizures, abnormal brain imaging, variable dysmorphic features, and various congenital anomalies. The wide application and increasing accessibility of whole exome sequencing (WES) has helped to identify new cases of ZTTK syndrome over the last few years. To date, there have been approximately 45 cases reported in the literature. Here, we describe 15 additional individuals with variants in the SON gene, including those with missense variants bringing the total number of known cases to 60. We have reviewed the clinical and molecular data of these new cases and all previously reported cases to further delineate the most common as well as emerging clinical findings related to this syndrome. Furthermore, we aim to delineate any genotype-phenotype correlations specifically for a recurring pathogenic four base pair deletion (c.5753_5756del) along with discussing the impact of missense variants seen in the SON gene.


Asunto(s)
Anomalías Congénitas/genética , Proteínas de Unión al ADN/genética , Discapacidad Intelectual/genética , Antígenos de Histocompatibilidad Menor/genética , Convulsiones/genética , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Anomalías Congénitas/diagnóstico , Anomalías Congénitas/patología , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/patología , Masculino , Mutación Missense/genética , Fenotipo , Convulsiones/diagnóstico , Convulsiones/patología , Secuenciación del Exoma
11.
Epilepsia ; 62(7): e103-e109, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34041744

RESUMEN

CSNK2B has recently been implicated as a disease gene for neurodevelopmental disability (NDD) and epilepsy. Information about developmental outcomes has been limited by the young age and short follow-up for many of the previously reported cases, and further delineation of the spectrum of associated phenotypes is needed. We present 25 new patients with variants in CSNK2B and refine the associated NDD and epilepsy phenotypes. CSNK2B variants were identified by research or clinical exome sequencing, and investigators from different centers were connected via GeneMatcher. Most individuals had developmental delay and generalized epilepsy with onset in the first 2 years. However, we found a broad spectrum of phenotypic severity, ranging from early normal development with pharmacoresponsive seizures to profound intellectual disability with intractable epilepsy and recurrent refractory status epilepticus. These findings suggest that CSNK2B should be considered in the diagnostic evaluation of patients with a broad range of NDD with treatable or intractable seizures.


Asunto(s)
Discapacidades del Desarrollo/genética , Epilepsia Generalizada/genética , Adolescente , Adulto , Edad de Inicio , Niño , Preescolar , Discapacidades del Desarrollo/fisiopatología , Epilepsias Mioclónicas/diagnóstico , Epilepsias Mioclónicas/etiología , Epilepsias Mioclónicas/genética , Epilepsia Generalizada/diagnóstico , Epilepsia Generalizada/etiología , Exoma/genética , Femenino , Variación Genética , Humanos , Lactante , Discapacidad Intelectual/etiología , Discapacidad Intelectual/genética , Masculino , Mutación/genética , Fenotipo , Estado Epiléptico/diagnóstico , Estado Epiléptico/etiología , Estado Epiléptico/genética , Adulto Joven
12.
Genet Med ; 23(2): 374-383, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33077894

RESUMEN

PURPOSE: JARID2, located on chromosome 6p22.3, is a regulator of histone methyltransferase complexes that is expressed in human neurons. So far, 13 individuals sharing clinical features including intellectual disability (ID) were reported with de novo heterozygous deletions in 6p22-p24 encompassing the full length JARID2 gene (OMIM 601594). However, all published individuals to date have a deletion of at least one other adjoining gene, making it difficult to determine if JARID2 is the critical gene responsible for the shared features. We aim to confirm JARID2 as a human disease gene and further elucidate the associated clinical phenotype. METHODS: Chromosome microarray analysis, exome sequencing, and an online matching platform (GeneMatcher) were used to identify individuals with single-nucleotide variants or deletions involving JARID2. RESULTS: We report 16 individuals in 15 families with a deletion or single-nucleotide variant in JARID2. Several of these variants are likely to result in haploinsufficiency due to nonsense-mediated messenger RNA (mRNA) decay. All individuals have developmental delay and/or ID and share some overlapping clinical characteristics such as facial features with those who have larger deletions involving JARID2. CONCLUSION: We report that JARID2 haploinsufficiency leads to a clinically distinct neurodevelopmental syndrome, thus establishing gene-disease validity for the purpose of diagnostic reporting.


Asunto(s)
Discapacidad Intelectual , Trastornos del Neurodesarrollo , Haploinsuficiencia/genética , Heterocigoto , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Trastornos del Neurodesarrollo/diagnóstico , Trastornos del Neurodesarrollo/genética , Fenotipo , Complejo Represivo Polycomb 2/genética , Síndrome , Secuenciación del Exoma
13.
Front Physiol ; 11: 1040, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33013448

RESUMEN

Pathogenic variants in KCNQ2 and KCNQ3, paralogous genes encoding Kv7.2 and Kv7.3 voltage-gated K+ channel subunits, are responsible for early-onset developmental/epileptic disorders characterized by heterogeneous clinical phenotypes ranging from benign familial neonatal epilepsy (BFNE) to early-onset developmental and epileptic encephalopathy (DEE). KCNQ2 variants account for the majority of pedigrees with BFNE and KCNQ3 variants are responsible for a much smaller subgroup, but the reasons for this imbalance remain unclear. Analysis of additional pedigrees is needed to further clarify the nature of this genetic heterogeneity and to improve prediction of pathogenicity for novel variants. We identified a BFNE family with two siblings and a parent affected. Exome sequencing on samples from both parents and siblings revealed a novel KCNQ3 variant (c.719T>G; p.M240R), segregating in the three affected individuals. The M240 residue is conserved among human Kv7.2-5 and lies between the two arginines (R5 and R6) closest to the intracellular side of the voltage-sensing S4 transmembrane segment. Whole cell patch-clamp recordings in Chinese hamster ovary (CHO) cells revealed that homomeric Kv7.3 M240R channels were not functional, whereas heteromeric channels incorporating Kv7.3 M240R mutant subunits with Kv7.2 and Kv7.3 displayed a depolarizing shift of about 10 mV in activation gating. Molecular modeling results suggested that the M240R substitution preferentially stabilized the resting state and possibly destabilized the activated state of the Kv7.3 subunits, a result consistent with functional data. Exposure to ß-hydroxybutyrate (BHB), a ketone body generated during the ketogenic diet (KD), reversed channel dysfunction induced by the M240R variant. In conclusion, we describe the first missense loss-of-function (LoF) pathogenic variant within the S4 segment of Kv7.3 identified in patients with BFNE. Studied under conditions mimicking heterozygosity, the M240R variant mainly affects the voltage sensitivity, in contrast to previously analyzed BFNE Kv7.3 variants that reduce current density. Our pharmacological results provide a rationale for the use of KD in patients carrying LoF variants in Kv7.2 or Kv7.3 subunits.

14.
N Engl J Med ; 383(12): 1107-1116, 2020 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-32786180

RESUMEN

BACKGROUND: In the majority of cases, the cause of stillbirth remains unknown despite detailed clinical and laboratory evaluation. Approximately 10 to 20% of stillbirths are attributed to chromosomal abnormalities. However, the causal nature of single-nucleotide variants and small insertions and deletions in exomes has been understudied. METHODS: We generated exome sequencing data for 246 stillborn cases and followed established guidelines to identify causal variants in disease-associated genes. These genes included those that have been associated with stillbirth and strong candidate genes. We also evaluated the contribution of 18,653 genes in case-control analyses stratified according to the degree of depletion of functional variation (described here as "intolerance" to variation). RESULTS: We identified molecular diagnoses in 15 of 246 cases of stillbirth (6.1%) involving seven genes that have been implicated in stillbirth and six disease genes that are good candidates for phenotypic expansion. Among the cases we evaluated, we also found an enrichment of loss-of-function variants in genes that are intolerant to such variation in the human population (odds ratio, 2.15; 95% confidence interval [CI], 1.46 to 3.06). Loss-of-function variants in intolerant genes were concentrated in genes that have not been associated with human disease (odds ratio, 2.22; 95% CI, 1.41 to 3.34), findings that differ from those in two postnatal clinical populations that were also evaluated in this study. CONCLUSIONS: Our findings establish the diagnostic utility of clinical exome sequencing to evaluate the role of small genomic changes in stillbirth. The strength of the novel risk signal (as generated through the stratified analysis) was similar to that in known disease genes, which indicates that the genetic cause of stillbirth remains largely unknown. (Funded by the Institute for Genomic Medicine.).


Asunto(s)
Variación Genética , Mutación , Mortinato/genética , Femenino , Mutación del Sistema de Lectura , Humanos , Mutación con Pérdida de Función , Mutación Missense , Embarazo , Secuenciación del Exoma
15.
Am J Hum Genet ; 107(3): 544-554, 2020 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-32730804

RESUMEN

RNA polymerase II interacts with various other complexes and factors to ensure correct initiation, elongation, and termination of mRNA transcription. One of these proteins is SR-related CTD-associated factor 4 (SCAF4), which is important for correct usage of polyA sites for mRNA termination. Using exome sequencing and international matchmaking, we identified nine likely pathogenic germline variants in SCAF4 including two splice-site and seven truncating variants, all residing in the N-terminal two thirds of the protein. Eight of these variants occurred de novo, and one was inherited. Affected individuals demonstrated a variable neurodevelopmental disorder characterized by mild intellectual disability, seizures, behavioral abnormalities, and various skeletal and structural anomalies. Paired-end RNA sequencing on blood lymphocytes of SCAF4-deficient individuals revealed a broad deregulation of more than 9,000 genes and significant differential splicing of more than 2,900 genes, indicating an important role of SCAF4 in mRNA processing. Knockdown of the SCAF4 ortholog CG4266 in the model organism Drosophila melanogaster resulted in impaired locomotor function, learning, and short-term memory. Furthermore, we observed an increased number of active zones in larval neuromuscular junctions, representing large glutamatergic synapses. These observations indicate a role of CG4266 in nervous system development and function and support the implication of SCAF4 in neurodevelopmental phenotypes. In summary, our data show that heterozygous, likely gene-disrupting variants in SCAF4 are causative for a variable neurodevelopmental disorder associated with impaired mRNA processing.


Asunto(s)
Discapacidad Intelectual/genética , Trastornos del Neurodesarrollo/genética , Convulsiones/genética , Factores de Empalme Serina-Arginina/genética , Animales , Niño , Drosophila melanogaster/genética , Femenino , Técnicas de Silenciamiento del Gen , Variación Genética/genética , Heterocigoto , Humanos , Discapacidad Intelectual/fisiopatología , Locomoción/genética , Masculino , Mutación/genética , Trastornos del Neurodesarrollo/fisiopatología , ARN Polimerasa II/genética , Procesamiento Postranscripcional del ARN/genética , ARN Mensajero/genética , Convulsiones/fisiopatología , Secuenciación del Exoma
16.
Ann Neurol ; 88(2): 348-362, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32515017

RESUMEN

OBJECTIVE: Pathogenic variants in SCN3A, encoding the voltage-gated sodium channel subunit Nav1.3, cause severe childhood onset epilepsy and malformation of cortical development. Here, we define the spectrum of clinical, genetic, and neuroimaging features of SCN3A-related neurodevelopmental disorder. METHODS: Patients were ascertained via an international collaborative network. We compared sodium channels containing wild-type versus variant Nav1.3 subunits coexpressed with ß1 and ß2 subunits using whole-cell voltage clamp electrophysiological recordings in a heterologous mammalian system (HEK-293T cells). RESULTS: Of 22 patients with pathogenic SCN3A variants, most had treatment-resistant epilepsy beginning in the first year of life (16/21, 76%; median onset, 2 weeks), with severe or profound developmental delay (15/20, 75%). Many, but not all (15/19, 79%), exhibited malformations of cortical development. Pathogenic variants clustered in transmembrane segments 4 to 6 of domains II to IV. Most pathogenic missense variants tested (10/11, 91%) displayed gain of channel function, with increased persistent current and/or a leftward shift in the voltage dependence of activation, and all variants associated with malformation of cortical development exhibited gain of channel function. One variant (p.Ile1468Arg) exhibited mixed effects, with gain and partial loss of function. Two variants demonstrated loss of channel function. INTERPRETATION: Our study defines SCN3A-related neurodevelopmental disorder along a spectrum of severity, but typically including epilepsy and severe or profound developmental delay/intellectual disability. Malformations of cortical development are a characteristic feature of this unusual channelopathy syndrome, present in >75% of affected individuals. Gain of function at the channel level in developing neurons is likely an important mechanism of disease pathogenesis. ANN NEUROL 2020;88:348-362.


Asunto(s)
Encéfalo/diagnóstico por imagen , Epilepsia/diagnóstico por imagen , Epilepsia/genética , Canal de Sodio Activado por Voltaje NAV1.3/genética , Trastornos del Neurodesarrollo/diagnóstico por imagen , Trastornos del Neurodesarrollo/genética , Canales de Sodio/genética , Adolescente , Adulto , Niño , Preescolar , Femenino , Feto/diagnóstico por imagen , Variación Genética/genética , Células HEK293 , Humanos , Lactante , Masculino
18.
Genet Med ; 21(10): 2371-2380, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-30930462

RESUMEN

PURPOSE: Recruitment of participants from diverse backgrounds is crucial to the generalizability of genetic research, but has proven challenging. We retrospectively evaluated recruitment methods used for a study on return of genetic results. METHODS: The costs of study design, development, and participant enrollment were calculated, and the characteristics of the participants enrolled through the seven recruitment methods were examined. RESULTS: A total of 1118 participants provided consent, a blood sample, and questionnaire data. The estimated cost across recruitment methods ranged from $579 to $1666 per participant and required a large recruitment team. Recruitment methods using flyers and staff networks were the most cost-efficient and resulted in the highest completion rate. Targeted sampling that emphasized the importance of Latino/a participation, utilization of translated materials, and in-person recruitments contributed to enrolling a demographically diverse sample. CONCLUSIONS: Although all methods were deployed in the same hospital or neighborhood and shared the same staff, each recruitment method was different in terms of cost and characteristics of the enrolled participants, suggesting the importance of carefully choosing the recruitment methods based on the desired composition of the final study sample. This analysis provides information about the effectiveness and cost of different methods to recruit adults for genetic research.


Asunto(s)
Ensayos Clínicos como Asunto/economía , Pruebas Genéticas/economía , Selección de Paciente/ética , Adulto , Ensayos Clínicos como Asunto/métodos , Costos y Análisis de Costo , Etnicidad , Femenino , Genómica/economía , Genómica/métodos , Humanos , Masculino , Tamizaje Masivo/economía , Persona de Mediana Edad , Proyectos de Investigación , Estudios Retrospectivos
19.
Ann Neurol ; 84(5): 788-795, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30269351

RESUMEN

NBEA is a candidate gene for autism, and de novo variants have been reported in neurodevelopmental disease (NDD) cohorts. However, NBEA has not been rigorously evaluated as a disease gene, and associated phenotypes have not been delineated. We identified 24 de novo NBEA variants in patients with NDD, establishing NBEA as an NDD gene. Most patients had epilepsy with onset in the first few years of life, often characterized by generalized seizure types, including myoclonic and atonic seizures. Our data show a broader phenotypic spectrum than previously described, including a myoclonic-astatic epilepsy-like phenotype in a subset of patients. Ann Neurol 2018;84:796-803.


Asunto(s)
Proteínas Portadoras/genética , Proteínas del Tejido Nervioso/genética , Trastornos del Neurodesarrollo/genética , Adolescente , Niño , Preescolar , Epilepsia Generalizada/genética , Femenino , Genotipo , Humanos , Masculino , Mutación , Fenotipo
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