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 , LactanteRESUMEN
Focal segmental glomerulosclerosis (FSGS) is the main pathology underlying steroid-resistant nephrotic syndrome (SRNS) and a leading cause of chronic kidney disease. Monogenic forms of pediatric SRNS are predominantly caused by recessive mutations, while the contribution of de novo variants (DNVs) to this trait is poorly understood. Using exome sequencing (ES) in a proband with FSGS/SRNS, developmental delay, and epilepsy, we discovered a nonsense DNV in TRIM8, which encodes the E3 ubiquitin ligase tripartite motif containing 8. To establish whether TRIM8 variants represent a cause of FSGS, we aggregated exome/genome-sequencing data for 2,501 pediatric FSGS/SRNS-affected individuals and 48,556 control subjects, detecting eight heterozygous TRIM8 truncating variants in affected subjects but none in control subjects (p = 3.28 × 10-11). In all six cases with available parental DNA, we demonstrated de novo inheritance (p = 2.21 × 10-15). Reverse phenotyping revealed neurodevelopmental disease in all eight families. We next analyzed ES from 9,067 individuals with epilepsy, yielding three additional families with truncating TRIM8 variants. Clinical review revealed FSGS in all. All TRIM8 variants cause protein truncation clustering within the last exon between residues 390 and 487 of the 551 amino acid protein, indicating a correlation between this syndrome and loss of the TRIM8 C-terminal region. Wild-type TRIM8 overexpressed in immortalized human podocytes and neuronal cells localized to nuclear bodies, while constructs harboring patient-specific variants mislocalized diffusely to the nucleoplasm. Co-localization studies demonstrated that Gemini and Cajal bodies frequently abut a TRIM8 nuclear body. Truncating TRIM8 DNVs cause a neuro-renal syndrome via aberrant TRIM8 localization, implicating nuclear bodies in FSGS and developmental brain disease.
Asunto(s)
Proteínas Portadoras/genética , Discapacidades del Desarrollo/genética , Epilepsia/genética , Glomeruloesclerosis Focal y Segmentaria/genética , Espacio Intranuclear/metabolismo , Síndrome Nefrótico/genética , Síndrome Nefrótico/metabolismo , Proteínas del Tejido Nervioso/genética , Adulto , Animales , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Línea Celular , Niño , Preescolar , Codón sin Sentido , Discapacidades del Desarrollo/metabolismo , Epilepsia/metabolismo , Femenino , Glomeruloesclerosis Focal y Segmentaria/metabolismo , Humanos , Riñón/metabolismo , Masculino , Ratones , Mutación , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/metabolismo , Fenotipo , Podocitos/metabolismo , Secuenciación del ExomaRESUMEN
Genetic counseling for patients who are pursuing genetic testing in the absence of a medical indication, referred to as elective genomic testing (EGT), is becoming more common. This type of testing has the potential to detect genetic conditions before there is a significant health impact permitting earlier management and/or treatment. Pre- and post-test counseling for EGT is similar to indication-based genetic testing. Both require a complete family and medical history when ordering a test or interpreting a result. However, EGT counseling has some special considerations including greater uncertainties around penetrance and clinical utility and a lack of published guidelines. While certain considerations in the selection of a high-quality genetic testing laboratory are universal, there are some considerations that are unique to the selection of a laboratory performing EGT. This practice resource intends to provide guidance for genetic counselors and other healthcare providers caring for adults seeking pre- or post-test counseling for EGT. Genetic counselors and other genetics trained healthcare providers are the ideal medical professionals to supply accurate information to individuals seeking counseling about EGT enabling them to make informed decisions about testing and follow-up.
Asunto(s)
Consejeros , Adulto , Humanos , Pruebas Genéticas , Asesoramiento Genético , Consejo , GenómicaRESUMEN
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/métodosRESUMEN
OBJECTIVE: Numerous genetic testing options for individuals with epilepsy have emerged over the past decade without clear guidelines regarding optimal testing strategies. We performed a systematic evidence review (SER) and conducted meta-analyses of the diagnostic yield of genetic tests commonly utilized for patients with epilepsy. We also assessed nonyield outcomes (NYOs) such as changes in treatment and/or management, prognostic information, recurrence risk determination, and genetic counseling. METHODS: We performed an SER, in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), using PubMed, Embase, CINAHL, and Cochrane Central through December of 2020. We included studies that utilized genome sequencing (GS), exome sequencing (ES), multigene panel (MGP), and/or genome-wide comparative genomic hybridization/chromosomal microarray (CGH/CMA) in cohorts (n ≥ 10) ascertained for epilepsy. Quality assessment was undertaken using ROBINS-I (Risk of Bias in Non-Randomized Studies of Interventions). We estimated diagnostic yields and 95% confidence intervals with random effects meta-analyses and narratively synthesized NYOs. RESULTS: From 5985 nonduplicated articles published through 2020, 154 met inclusion criteria and were included in meta-analyses of diagnostic yield; 43 of those were included in the NYO synthesis. The overall diagnostic yield across all test modalities was 17%, with the highest yield for GS (48%), followed by ES (24%), MGP (19%), and CGH/CMA (9%). The only phenotypic factors that were significantly associated with increased yield were (1) the presence of developmental and epileptic encephalopathy and/or (2) the presence of neurodevelopmental comorbidities. Studies reporting NYOs addressed clinical and personal utility of testing. SIGNIFICANCE: This comprehensive SER, focused specifically on the literature regarding patients with epilepsy, provides a comparative assessment of the yield of clinically available tests, which will help shape clinician decision-making and policy regarding insurance coverage for genetic testing. We highlight the need for prospective assessment of the clinical and personal utility of genetic testing for patients with epilepsy and for standardization in reporting patient characteristics.
Asunto(s)
Epilepsia , Pruebas Genéticas , Hibridación Genómica Comparativa , Epilepsia/diagnóstico , Epilepsia/genética , Humanos , Estudios Prospectivos , Secuenciación del ExomaRESUMEN
Genetic testing is performed more routinely in clinical practice, and direct-to-consumer tests are widely available. It has obvious appeal as a preventive health measure. Clinicians and their healthy patients increasingly inquire about genetic testing as a tool for predicting diseases, such as cancer, heart disease, or dementia. Despite demonstrated utility for diagnosis in the setting of many diseases, genetic testing still has many limitations as a predictive tool for healthy persons. This article uses a hypothetical case to review key considerations for predictive genetic testing.
Asunto(s)
Pruebas Genéticas , Selección de Paciente , Medicina de Precisión , Pruebas Dirigidas al Consumidor , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Variación Genética , Humanos , Anamnesis , Valor Predictivo de las PruebasRESUMEN
PURPOSE: In this study, we aimed to characterize the clinical phenotype of a SHANK1-related disorder and define the functional consequences of SHANK1 truncating variants. METHODS: Exome sequencing (ES) was performed for six individuals who presented with neurodevelopmental disorders. Individuals were ascertained with the use of GeneMatcher and Database of Chromosomal Imbalance and Phenotype in Humans Using Ensembl Resources (DECIPHER). We evaluated potential nonsense-mediated decay (NMD) of two variants by making knock-in cell lines of endogenous truncated SHANK1, and expressed the truncated SHANK1 complementary DNA (cDNA) in HEK293 cells and cultured hippocampal neurons to examine the proteins. RESULTS: ES detected de novo truncating variants in SHANK1 in six individuals. Evaluation of NMD resulted in stable transcripts, and the truncated SHANK1 completely lost binding with Homer1, a linker protein that binds to the C-terminus of SHANK1. These variants may disrupt protein-protein networks in dendritic spines. Dispersed localization of the truncated SHANK1 variants within the spine and dendritic shaft was also observed when expressed in neurons, indicating impaired synaptic localization of truncated SHANK1. CONCLUSION: This report expands the clinical spectrum of individuals with truncating SHANK1 variants and describes the impact these variants may have on the pathophysiology of neurodevelopmental disorders.
Asunto(s)
Proteínas del Tejido Nervioso , Trastornos del Neurodesarrollo , Células HEK293 , Humanos , Proteínas del Tejido Nervioso/genética , Trastornos del Neurodesarrollo/genética , Neuronas , Fenotipo , Secuenciación del ExomaRESUMEN
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 JovenRESUMEN
AIM To determine which patients with cerebral palsy (CP) should undergo genetic testing, we compared the rate of likely causative genetic variants from whole-exome sequencing in individuals with and without environmental risk factors. METHOD Patients were part of a convenience and physician-referred cohort recruited from a single medical center, and research whole-exome sequencing was completed. Participants were evaluated for the following risk factors: extreme preterm birth, brain bleed or stroke, birth asphyxia, brain malformations, and intrauterine infection. RESULTS A total of 151 unrelated individuals with CP (81 females, 70 males; mean age 25y 7mo [SD 17y 5mo], range 3wks-72y) participated. Causative genetic variants were identified in 14 participants (9.3%). There was no significant difference in diagnostic rate between individuals with risk factors (10 out of 123; 8.1%) and those without (4 out of 28; 14.3%) (Fisher's exact p=0.3). INTERPRETATION While the rate of genetic diagnoses among individuals without risk factors was higher than those with risk factors, the difference was not statistically significant at this sample size. The identification of genetic diagnoses in over 8% of cases with risk factors suggests that these might confer susceptibility to environmental factors, and that further research should include individuals with risk factors. What this paper adds There is no significant difference in diagnostic rate between individuals with and without risk factors. Genetic variants may confer susceptibility to environmental risk factors. Six causative variants were identified in genes not previously associated with cerebral palsy. Global developmental delay/intellectual disability is positively associated with a genetic etiology. Extreme preterm birth, stroke/brain hemorrhage, and older age are negatively associated with a genetic etiology.
Asunto(s)
Parálisis Cerebral/genética , Variación Genética , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Pruebas Genéticas , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Nacimiento Prematuro , Secuenciación del Exoma , Adulto JovenRESUMEN
BACKGROUND: Identification of chromosomal aneuploidies and copy number variants that are associated with fetal structural anomalies has substantial value. Although whole-exome sequencing (WES) has been applied to case series of a few selected prenatal cases, its value in routine clinical settings has not been prospectively assessed in a large unselected cohort of fetuses with structural anomalies. We therefore aimed to determine the incremental diagnostic yield (ie, the added value) of WES following uninformative results of standard investigations with karyotype testing and chromosomal microarray in an unselected cohort of sequential pregnancies showing fetal structural anomalies. METHODS: In this prospective cohort study, the parents of fetuses who were found to have a structural anomaly in a prenatal ultrasound were screened for possible participation in the study. These participants were predominantly identified in or were referred to the Columbia University Carmen and John Thain Center for Prenatal Pediatrics (New York, NY, USA). Fetuses with confirmed aneuploidy or a causal pathogenic copy number variant were excluded from WES analyses. By use of WES of the fetuses and parents (parent-fetus trios), we identified genetic variants that indicated an underlying cause (diagnostic genetic variants) and genetic variants that met the criteria of bioinformatic signatures that had previously been described to be significantly enriched among diagnostic genetic variants. FINDINGS: Between April 24, 2015, and April 19, 2017, 517 sequentially identified pregnant women found to have fetuses with a structural anomaly were screened for their eligibility for inclusion in our study. 71 (14%) couples declined testing, 87 (17%) trios were missing at least one DNA sample (from either parent or the fetus), 69 (13%) trios had a clinically relevant abnormal karyotype or chromosomal microarray finding, 51 (10%) couples did not consent to WES or withdrew consent, and five (1%) samples were not of good enough quality for analysis. DNA samples from 234 (45%) eligible trios were therefore used for analysis of the primary outcome. By use of trio sequence data, we identified diagnostic genetic variants in 24 (10%) families. Mutations with bioinformatic signatures that were indicative of pathogenicity but with insufficient evidence to be considered diagnostic were also evaluated; 46 (20%) of the 234 fetuses assessed were found to have such signatures. INTERPRETATION: Our analysis of WES data in a prospective cohort of unselected fetuses with structural anomalies shows the value added by WES following the use of routine genetic tests. Our findings suggest that, in cases of fetal anomalies in which assessment with karyotype testing and chromosomal microarray fail to determine the underlying cause of a structural anomaly, WES can add clinically relevant information that could assist current management of a pregnancy. The unique challenges of WES-based prenatal diagnostics require analysis by a multidisciplinary team of perinatal practitioners and laboratory specialists. FUNDING: Institute for Genomic Medicine (Columbia University Irving Medical Center).
Asunto(s)
Cariotipo Anormal/embriología , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Aneuploidia , Variaciones en el Número de Copia de ADN/genética , Secuenciación del Exoma/estadística & datos numéricos , Desarrollo Fetal/genética , Feto/anomalías , Anomalías Múltiples/epidemiología , Amniocentesis , Muestra de la Vellosidad Coriónica , Femenino , Tamización de Portadores Genéticos , Humanos , Masculino , Embarazo , Estudios Prospectivos , Ultrasonografía Prenatal , Secuenciación del Exoma/métodosRESUMEN
Background: Exome sequencing is increasingly being used for clinical diagnostics, with an impetus to expand reporting of incidental findings across a wide range of disorders. Analysis of population cohorts can help reduce risk for genetic variant misclassification and resultant unnecessary referrals to subspecialists. Objective: To examine the burden of candidate pathogenic variants for kidney and genitourinary disorders emerging from exome sequencing. Design: Secondary analysis of genetic data. Setting: A tertiary care academic medical center. Patients: A convenience sample of exome sequence data from 7974 self-declared healthy adults. Measurements: Assessment of the prevalence of candidate pathogenic variants in 625 genes associated with Mendelian kidney and genitourinary disorders. Results: Of all participants, 23.3% carried a candidate pathogenic variant, most of which were attributable to previously reported variants that had implausibly high allele frequencies. In particular, 25 genes (discovered before the creation of the Exome Aggregation Consortium, a genetic database comprising data from a large control population) accounted for 67.7% of persons with candidate pathogenic variants. After stringent filtering based on allele frequency, 1.4% of persons still had a candidate pathogenic variant, an excessive rate given the prevalence of monogenic kidney and genitourinary disorders. Manual annotation of a subset of variants showed that the majority would be classified as nonbenign under current guidelines for clinical sequence interpretation and could prompt subspecialty referrals if returned. Limitation: Limited access to health record data prevented comprehensive assessment of the phenotypic concordance with genetic diagnoses. Conclusion: Widespread reporting of incidental genetic findings related to kidney and genitourinary disorders will require stringent curation of clinical variant databases and detailed case-level review to avoid genetic misdiagnosis and unnecessary referrals. These findings motivate similar analyses for genes relevant to other medical subspecialties. Primary Funding Source: National Institute of Diabetes and Digestive and Kidney Diseases and National Human Genome Research Institute.
Asunto(s)
Secuenciación del Exoma , Enfermedades Urogenitales Femeninas/genética , Enfermedades Renales/genética , Enfermedades Urogenitales Masculinas/genética , Adulto , Anciano , Errores Diagnósticos , Femenino , Frecuencia de los Genes , Humanos , Hallazgos Incidentales , Masculino , Uso Excesivo de los Servicios de Salud , Derivación y ConsultaRESUMEN
Whole-exome sequencing of 13 individuals with developmental delay commonly accompanied by abnormal muscle tone and seizures identified de novo missense mutations enriched within a sub-region of GNB1, a gene encoding the guanine nucleotide-binding protein subunit beta-1, Gß. These 13 individuals were identified among a base of 5,855 individuals recruited for various undiagnosed genetic disorders. The probability of observing 13 or more de novo mutations by chance among 5,855 individuals is very low (p = 7.1 × 10(-21)), implicating GNB1 as a genome-wide-significant disease-associated gene. The majority of these 13 mutations affect known Gß binding sites, which suggests that a likely disease mechanism is through the disruption of the protein interface required for Gα-Gßγ interaction (resulting in a constitutively active Gßγ) or through the disruption of residues relevant for interaction between Gßγ and certain downstream effectors (resulting in reduced interaction with the effectors). Strikingly, 8 of the 13 individuals recruited here for a neurodevelopmental disorder have a germline de novo GNB1 mutation that overlaps a set of five recurrent somatic tumor mutations for which recent functional studies demonstrated a gain-of-function effect due to constitutive activation of G protein downstream signaling cascades for some of the affected residues.
Asunto(s)
Discapacidades del Desarrollo/etiología , Subunidades beta de la Proteína de Unión al GTP/genética , Mutación de Línea Germinal/genética , Discapacidad Intelectual/etiología , Hipotonía Muscular/etiología , Convulsiones/etiología , Adolescente , Adulto , Niño , Preescolar , Discapacidades del Desarrollo/patología , Exoma/genética , Femenino , Subunidades beta de la Proteína de Unión al GTP/química , Humanos , Lactante , Discapacidad Intelectual/patología , Masculino , Hipotonía Muscular/patología , Fenotipo , Conformación Proteica , Convulsiones/patología , Transducción de Señal , Adulto JovenRESUMEN
The original version of this Article contained an error in the undergraduate degree awarded to the author Ian Halim, which was incorrectly given as BS. This has now been corrected to BA in both the PDF and HTML versions of the Article.
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 RetrospectivosRESUMEN
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 , FenotipoRESUMEN
De novo germline mutations in GNB1 have been associated with a neurodevelopmental phenotype. To date, 28 patients with variants classified as pathogenic have been reported. We add 18 patients with de novo mutations to this cohort, including a patient with mosaicism for a GNB1 mutation who presented with a milder phenotype. Consistent with previous reports, developmental delay in these patients was moderate to severe, and more than half of the patients were non-ambulatory and nonverbal. The most observed substitution affects the p.Ile80 residue encoded in exon 6, with 28% of patients carrying a variant at this residue. Dystonia and growth delay were observed more frequently in patients carrying variants in this residue, suggesting a potential genotype-phenotype correlation. In the new cohort of 18 patients, 50% of males had genitourinary anomalies and 61% of patients had gastrointestinal anomalies, suggesting a possible association of these findings with variants in GNB1. In addition, cutaneous mastocytosis, reported once before in a patient with a GNB1 variant, was observed in three additional patients, providing further evidence for an association to GNB1. We will review clinical and molecular data of these new cases and all previously reported cases to further define the phenotype and establish possible genotype-phenotype correlations.
Asunto(s)
Subunidades beta de la Proteína de Unión al GTP/genética , Estudios de Asociación Genética , Mutación/genética , Adolescente , Niño , Preescolar , Estudios de Cohortes , Epilepsia/genética , Femenino , Subunidades beta de la Proteína de Unión al GTP/química , Humanos , Masculino , Sistema Nervioso/crecimiento & desarrollo , Fenotipo , Embarazo , Estructura Terciaria de ProteínaRESUMEN
Gaucher disease (GD) is an autosomal recessive disease caused by GBA mutations that is especially common in the Ashkenazi Jewish (AJ) population. The link between GBA mutations and Parkinson disease (PD), a later-onset neurodegenerative condition, is well established, and studies have shown that GBA carriers have an increased lifetime risk of developing PD. Carrier screening for GD is frequently offered to couples during or prior to pregnancy, especially to those of AJ descent. However, no studies have been performed to assess if prospective parents would want to learn about their risk of developing PD incidentally through carrier screening. It is also unknown if pre-test counseling on this topic would affect screening uptake. In order to answer these questions, a survey was administered to individuals who screened negative for GBA mutations. Of the 75 participants, 86.7% believed that patients should be informed about the increased risk of PD prior to having GD carrier screening, and 93.3% responded that this information would not have changed their decision to have carrier screening. These results indicate that healthcare providers should take into consideration patient preferences when determining how to counsel about GD carrier screening. Additionally, these results have implications for genetic counseling about other later-onset conditions that may be incidentally ascertained through carrier screening.
Asunto(s)
Enfermedad de Gaucher/genética , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Enfermedad de Parkinson/psicología , Toma de Decisiones , Femenino , Enfermedad de Gaucher/complicaciones , Humanos , Masculino , Enfermedad de Parkinson/complicaciones , Embarazo , Estudios ProspectivosRESUMEN
PURPOSE: The overall published experience with pediatric type 1 Gaucher disease (GD1) has been based on ascertainment through clinical presentation of the disease. We describe the longitudinal follow-up in a presymptomatic pediatric cohort. METHODS: The cohort includes children diagnosed with GD1, either prenatally or postnatally by molecular genetic testing, and followed for clinical care at our center from 1998 to 2016. All patients' parents were GBA mutation carriers identified through carrier screening programs. Longitudinal clinical, laboratory, and imaging data were obtained through chart review. RESULTS: Thirty-eight patients aged 1-18 years (mean at last visit 6.9 ± 4.1 years) were followed, including 32 p.N409S homozygotes and 6 p.N409S/p.R535H compound heterozygotes. At the last evaluation, a minority had hematological (5%), bone (15%), or linear growth (19%) issues. Only 12% had splenomegaly and 74% had moderate hepatomegaly. Chitotriosidase activity varied widely (6-5,640 nmol/hour/ml) and generally increased with age. Pediatric Gaucher severity scores (GSS) remained stable and within the mild-disease range for most (95%). Treatment for progressive disease during this period was recommended for four children. CONCLUSION: Most children with the p.N409S/p.N409S and p.N409S/p.R535H GD1 genotypes have minimal disease manifestations and progression during childhood and can be monitored using limited assessments. Those with other mutations may require additional monitoring. These data are valuable for newborn screening and counseling.Genet Med advance online publication 13 October 2016.
Asunto(s)
Enfermedad de Gaucher/diagnóstico , Tamización de Portadores Genéticos , Adolescente , Niño , Preescolar , Estudios de Cohortes , Femenino , Enfermedad de Gaucher/enzimología , Enfermedad de Gaucher/genética , Enfermedad de Gaucher/fisiopatología , Asesoramiento Genético , Hexosaminidasas/metabolismo , Humanos , Lactante , Estudios Longitudinales , Masculino , Padres , Índice de Severidad de la EnfermedadRESUMEN
The association between 1p32-p31 contiguous gene deletions and a distinct phenotype that includes anomalies of the corpus callosum, ventriculomegaly, developmental delay, seizures, and dysmorphic features has been long recognized and described. Recently, the observation of overlapping phenotypes in patients with chromosome translocations that disrupt NFIA (Nuclear factor I/A), a gene within this deleted region, and NFIA intragenic deletions has led to the hypothesis that NFIA is a critical gene within this region. The wide application and increasing accessibility of whole exome sequencing (WES) has helped identify new cases to support this hypothesis. Here, we describe four patients with loss-of-function variants in the NFIA gene identified through WES. The clinical presentation of these patients significantly overlaps with the phenotype described in previously reported cases of 1p32-p31 deletion syndrome, NFIA gene disruptions and intragenic NFIA deletions. Our cohort includes a mother and daughter as well as an unrelated individual who share the same nonsense variant (c.205C>T, p.Arg69Ter; NM_001145512.1). We also report a patient with a frameshift NFIA variant (c.159_160dupCC, p.Gln54ProfsTer49). We have compared published cases of 1p32-p31 microdeletion syndrome, translocations resulting in NFIA gene disruption, intragenic deletions, and loss-of-function mutations (including our four patients) to reveal that abnormalities of the corpus callosum, ventriculomegaly/hydrocephalus, macrocephaly, Chiari I malformation, dysmorphic features, developmental delay, hypotonia, and urinary tract defects are common findings. The consistent overlap in clinical presentation provides further evidence of the critical role of NFIA haploinsufficiency in the development of the 1p32-p31 microdeletion syndrome phenotype.
Asunto(s)
Agenesia del Cuerpo Calloso/genética , Malformación de Arnold-Chiari/genética , Discapacidades del Desarrollo/genética , Megalencefalia/genética , Factores de Transcripción NFI/genética , Malformaciones del Sistema Nervioso/genética , Adolescente , Adulto , Agenesia del Cuerpo Calloso/diagnóstico , Malformación de Arnold-Chiari/diagnóstico , Niño , Deleción Cromosómica , Cromosomas Humanos Par 1 , Estudios de Cohortes , Discapacidades del Desarrollo/diagnóstico , Femenino , Haploinsuficiencia , Humanos , Mutación con Pérdida de Función , Masculino , Megalencefalia/diagnóstico , Malformaciones del Sistema Nervioso/diagnóstico , Secuenciación del ExomaRESUMEN
OBJECTIVE: The All of Us Research Program aims to return value to participants by developing research capacity in communities. We describe a novel set of introductory exercises (Data Sandboxes) and specialized trainings to orient researchers to the Researcher Workbench to foster health equity research. MATERIALS AND METHODS: We developed a tailored training to familiarize researchers with the All of Us Research Program: (1) orientation, (2) tailored "data treasure hunt" using the Public Data Browser, and (3) overview of the analyses tools and platform. RESULTS: Participants' pre- and post-knowledge of the contents and structure of the All of Us dataset scores increased significantly after training. These trainings effectively engaged researchers in exploring this rich dataset. CONCLUSION: We describe ways of orienting and familiarizing a wide variety of researchers with the All of Us Research Program dataset, sparking their interest, and "jump-starting" their research.