RESUMEN
OBJECTIVE: Psychological birth trauma (BT), defined as an event that occurs during labor and delivery involving actual or threatened harm or death to the pregnant person and/or their baby, has been reported in up to one-third of births. Obstetrician-Gynecologists (OBGYNs) who personally experience BT are at a unique risk of re-traumatization upon return to work. We aimed to investigate the prevalence of personal BT among obstetricians and their perceptions of how personal BT impacts their experience of caring for obstetric patients. METHODS: We performed a web-based survey of OBGYNs who had given birth. Participants were recruited from the "OMG (OBGYN Mom Group)" on Facebook. The questionnaire assessed individual's personal experience of childbirth using items adapted from the "City Birth Trauma Scale" to assess post-traumatic symptoms related to their childbirth and patient interactions following personal experience of BT. Responses were categorized by whether or not the participant considered one or more of their own births to be traumatic. Post-traumatic stress symptoms (PTSS) and symptoms of occupational re-traumatization were compared by reported BT. Bivariable analyses were used. RESULTS: Of the 591 OBGYNs who completed the survey, 180 (30.5%) reported experiencing BT. Ninety-two percent of OBGYNs cared for birthing patients after giving birth. There were no differences in demographic or clinical practice characteristics between those with and without BT. OBGYNs with BT experienced PTSS including flashbacks (60.6% vs 14.4%), amnesia (36.7% vs 20.9%), and insomnia (24.4% vs 1.2%) at higher rates than those without BT (p<0.001). CONCLUSION: Almost 1/3 of OBGYNs in this sample reported personally experiencing BT, mirroring data from reported BT rates in the general population. Given OBGYNs are at a high risk for occupational re-traumatization, initiatives focused on improving support for birthing OBGYNs upon returning to work should be studied to assess impact on emotional wellness among practicing OBGYNs.
RESUMEN
The utilization of cell-free DNA (cfDNA) screening has expanded rapidly across the age spectrum of pregnant persons. With cfDNA's widespread adoption, genetic fetal sex is now often known before a phenotypic assessment on anatomic survey. CfDNA detects sex discordance in 1/1500 to 2000 pregnancies. Upon detection of sex discordance, lab error or other factors should first be assessed. Once other causes have been ruled out, this may indicate an underlying disorder/difference in sex development. A multidisciplinary team should coordinate diagnosis, treatment, and support for the family. This review discusses the diagnostic workup, emphasizing the multidisciplinary counseling and management of disorder/differences in sex development.
Asunto(s)
Ácidos Nucleicos Libres de Células , Atención Prenatal , Femenino , Embarazo , Humanos , Desarrollo SexualRESUMEN
Aminoacyl-tRNA synthetases (ARSs) are critical for protein translation. Pathogenic variants of ARSs have been previously associated with peripheral neuropathy and multisystem disease in heterozygotes and homozygotes, respectively. We report seven related children homozygous for a novel mutation in tyrosyl-tRNA synthetase (YARS, c.499C > A, p.Pro167Thr) identified by whole exome sequencing. This variant lies within a highly conserved interface required for protein homodimerization, an essential step in YARS catalytic function. Affected children expressed a more severe phenotype than previously reported, including poor growth, developmental delay, brain dysmyelination, sensorineural hearing loss, nystagmus, progressive cholestatic liver disease, pancreatic insufficiency, hypoglycemia, anemia, intermittent proteinuria, recurrent bloodstream infections and chronic pulmonary disease. Related adults heterozygous for YARS p.Pro167Thr showed no evidence of peripheral neuropathy on electromyography, in contrast to previous reports for other YARS variants. Analysis of YARS p.Pro167Thr in yeast complementation assays revealed a loss-of-function, hypomorphic allele that significantly impaired growth. Recombinant YARS p.Pro167Thr demonstrated normal subcellular localization, but greatly diminished ability to homodimerize in human embryonic kidney cells. This work adds to a rapidly growing body of research emphasizing the importance of ARSs in multisystem disease and significantly expands the allelic and clinical heterogeneity of YARS-associated human disease. A deeper understanding of the role of YARS in human disease may inspire innovative therapies and improve care of affected patients.
Asunto(s)
Enfermedades Genéticas Congénitas/genética , Predisposición Genética a la Enfermedad , Mutación con Pérdida de Función/genética , Tirosina-ARNt Ligasa/genética , Adulto , Dominio Catalítico/genética , Preescolar , Femenino , Enfermedades Genéticas Congénitas/fisiopatología , Pérdida Auditiva Sensorineural/diagnóstico por imagen , Pérdida Auditiva Sensorineural/genética , Pérdida Auditiva Sensorineural/fisiopatología , Heterocigoto , Homocigoto , Humanos , Lactante , Recién Nacido , Masculino , Mutación , Linaje , Fenotipo , Índice de Severidad de la Enfermedad , Secuenciación del Exoma , Levaduras/genéticaRESUMEN
Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed enzymes that ligate amino acids onto tRNA molecules. Genes encoding ARSs have been implicated in phenotypically diverse dominant and recessive human diseases. The charging of tRNAPHE with phenylalanine is performed by a tetrameric enzyme that contains two alpha (FARSA) and two beta (FARSB) subunits. To date, mutations in the genes encoding these subunits (FARSA and FARSB) have not been implicated in any human disease. Here, we describe a patient with a severe, lethal, multisystem, developmental phenotype who was compound heterozygous for FARSB variants: p.Thr256Met and p.His496Lysfs*14. Expression studies using fibroblasts isolated from the proband revealed a severe depletion of both FARSB and FARSA protein levels. These data indicate that the FARSB variants destabilize total phenylalanyl-tRNA synthetase levels, thus causing a loss-of-function effect. Importantly, our patient shows strong phenotypic overlap with patients that have recessive diseases associated with other ARS loci; these observations strongly support the pathogenicity of the identified FARSB variants and are consistent with the essential function of phenylalanyl-tRNA synthetase in human cells. In sum, our clinical, genetic, and functional analyses revealed the first FARSB variants associated with a human disease phenotype and expand the locus heterogeneity of ARS-related human disease.
Asunto(s)
Aminoacil-ARNt Sintetasas/genética , Predisposición Genética a la Enfermedad , Mutación con Pérdida de Función/genética , Aminoacil-ARNt Sintetasas/química , Aminoacil-ARNt Sintetasas/deficiencia , Regulación de la Expresión Génica , Humanos , Masculino , Fenotipo , Fenilalanina-ARNt Ligasa/genéticaRESUMEN
Histidyl-tRNA synthetase (HARS) ligates histidine to cognate tRNA molecules, which is required for protein translation. Mutations in HARS cause the dominant axonal peripheral neuropathy Charcot-Marie-Tooth disease type 2W (CMT2W); however, the precise molecular mechanism remains undefined. Here, we investigated three HARS missense mutations associated with CMT2W (p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly). The three mutations localize to the HARS catalytic domain and failed to complement deletion of the yeast ortholog (HTS1). Enzyme kinetics, differential scanning fluorimetry (DSF), and analytical ultracentrifugation (AUC) were employed to assess the effect of these substitutions on primary aminoacylation function and overall dimeric structure. Notably, the p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly HARS substitutions all led to reduced aminoacylation, providing a direct connection between CMT2W-linked HARS mutations and loss of canonical ARS function. While DSF assays revealed that only one of the variants (p.Val155Gly) was less thermally stable relative to wild-type, all three HARS mutants formed stable dimers, as measured by AUC. Our work represents the first biochemical analysis of CMT-associated HARS mutations and underscores how loss of the primary aminoacylation function can contribute to disease pathology.
Asunto(s)
Axones/patología , Histidina-ARNt Ligasa/metabolismo , Enfermedades del Sistema Nervioso Periférico/enzimología , Enfermedades del Sistema Nervioso Periférico/patología , Secuencia de Aminoácidos , Aminoacilación , Biocatálisis , Dominio Catalítico , Secuencia Conservada , Femenino , Prueba de Complementación Genética , Histidina-ARNt Ligasa/química , Histidina-ARNt Ligasa/genética , Histidina-ARNt Ligasa/aislamiento & purificación , Humanos , Cinética , Masculino , Mutación/genética , Linaje , Enfermedades del Sistema Nervioso Periférico/genética , Multimerización de Proteína , Especificidad por SustratoRESUMEN
Charcot-Marie-Tooth (CMT) disease is a genetically heterogeneous group of peripheral neuropathies. Mutations in several aminoacyl-tRNA synthetase (ARS) genes have been implicated in inherited CMT disease. There are 12 reported CMT-causing mutations dispersed throughout the primary sequence of the human glycyl-tRNA synthetase (GARS). While there is strong genetic evidence linking GARS mutations to CMT disease, the molecular pathology underlying the neuromuscular and sensory phenotypes is still not fully understood. In particular, it is unclear whether the mutations result in a toxic gain of function, a partial loss of activity related to translation, or a combination of these mechanisms. We identified a zebrafish allele of gars (gars(s266)). Homozygous mutant embryos carry a C->A transversion, that changes a threonine to a lysine, in a residue next to a CMT-associated human mutation. We show that the neuromuscular phenotype observed in animals homozygous for T209K Gars (T130K in GARS) is due to a loss of dimerization of the mutated protein. Furthermore, we show that the loss of function, dimer-deficient and human disease-associated G319R Gars (G240R in GARS) mutant protein is unable to rescue the above phenotype. Finally, we demonstrate that another human disease-associated mutant G605R Gars (G526 in GARS) dimerizes with the remaining wild-type protein in animals heterozygous for the T209K Gars and reduces the function enough to elicit a neuromuscular phenotype. Our data indicate that dimerization is required for the dominant neurotoxicity of disease-associated GARS mutations and provide a rapid, tractable model for studying newly identified GARS variants for a role in human disease.
Asunto(s)
Enfermedad de Charcot-Marie-Tooth/patología , Glicina-ARNt Ligasa/química , Glicina-ARNt Ligasa/genética , Mutación , Proteínas de Pez Cebra/química , Proteínas de Pez Cebra/genética , Animales , Células Cultivadas , Enfermedad de Charcot-Marie-Tooth/genética , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Glicina-ARNt Ligasa/metabolismo , Humanos , Modelos Biológicos , Fenotipo , Multimerización de Proteína , Pez Cebra/embriología , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/metabolismoRESUMEN
Mutations in genes encoding aminoacyl-tRNA synthetases are known to cause leukodystrophies and genetic leukoencephalopathies-heritable disorders that result in white matter abnormalities in the central nervous system. Here we report three individuals (two siblings and an unrelated individual) with severe infantile epileptic encephalopathy, clubfoot, absent deep tendon reflexes, extrapyramidal symptoms, and persistently deficient myelination on MRI. Analysis by whole exome sequencing identified mutations in the nuclear-encoded alanyl-tRNA synthetase (AARS) in these two unrelated families: the two affected siblings are compound heterozygous for p.Lys81Thr and p.Arg751Gly AARS, and the single affected child is homozygous for p.Arg751Gly AARS. The two identified mutations were found to result in a significant reduction in function. Mutations in AARS were previously associated with an autosomal-dominant inherited form of axonal neuropathy, Charcot-Marie-Tooth disease type 2N (CMT2N). The autosomal-recessive AARS mutations identified in the individuals described here, however, cause a severe infantile epileptic encephalopathy with a central myelin defect and peripheral neuropathy, demonstrating that defects of alanyl-tRNA charging can result in a wide spectrum of disease manifestations.
Asunto(s)
Anomalías Múltiples/genética , Alanina-ARNt Ligasa/genética , Epilepsia/genética , Modelos Moleculares , Vaina de Mielina/patología , Enfermedades del Sistema Nervioso Periférico/genética , Fenotipo , Anomalías Múltiples/patología , Alanina-ARNt Ligasa/química , Secuencia de Aminoácidos , Secuencia de Bases , Epilepsia/patología , Genes Recesivos/genética , Humanos , Lactante , Recién Nacido , Datos de Secuencia Molecular , Mutación/genética , Enfermedades del Sistema Nervioso Periférico/patología , Estudios Prospectivos , Análisis de Secuencia de ADN , Síndrome , Estados UnidosRESUMEN
Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed, essential enzymes responsible for charging tRNA with cognate amino acids-the first step in protein synthesis. ARSs are required for protein translation in the cytoplasm and mitochondria of all cells. Surprisingly, mutations in 28 of the 37 nuclear-encoded human ARS genes have been linked to a variety of recessive and dominant tissue-specific disorders. Current data indicate that impaired enzyme function is a robust predictor of the pathogenicity of ARS mutations. However, experimental model systems that distinguish between pathogenic and non-pathogenic ARS variants are required for implicating newly identified ARS mutations in disease. Here, we outline strategies to assist in predicting the pathogenicity of ARS variants and urge cautious evaluation of genetic and functional data prior to linking an ARS mutation to a human disease phenotype.
Asunto(s)
Aminoacil-ARNt Sintetasas/genética , Predisposición Genética a la Enfermedad , Neuropatía Hereditaria Motora y Sensorial/diagnóstico , Neuropatía Hereditaria Motora y Sensorial/genética , Mutación , Aminoacil-ARNt Sintetasas/metabolismo , Animales , Citoplasma/genética , Citoplasma/metabolismo , Modelos Animales de Enfermedad , Expresión Génica , Ligamiento Genético , Neuropatía Hereditaria Motora y Sensorial/enzimología , Neuropatía Hereditaria Motora y Sensorial/patología , Humanos , Ratones , Mitocondrias/genética , Mitocondrias/metabolismo , Linaje , Penetrancia , Fenotipo , PronósticoRESUMEN
Charcot-Marie-Tooth disease type 2D (CMT2D) is an autosomal-dominant axonal peripheral neuropathy characterized by impaired motor and sensory function in the distal extremities. Mutations in the glycyl-tRNA synthetase (GARS) gene cause CMT2D. GARS is a member of the ubiquitously expressed aminoacyl-tRNA synthetase (ARS) family and is responsible for charging tRNA with glycine. To date, 13 GARS mutations have been identified in patients with CMT disease. While functional studies have revealed loss-of-function characteristics, only four GARS mutations have been rigorously studied. Here, we report the functional evaluation of nine CMT-associated GARS mutations in tRNA charging, yeast complementation, and subcellular localization assays. Our results demonstrate that impaired function is a common characteristic of CMT-associated GARS mutations. Additionally, one mutation previously associated with CMT disease (p.Ser581Leu) does not demonstrate impaired function, was identified in the general population, and failed to segregate with disease in two newly identified families with CMT disease. Thus, we propose that this variant is not a disease-causing mutation. Together, our data indicate that impaired function is a key component of GARS-mediated CMT disease and emphasize the need for careful genetic and functional evaluation before implicating a variant in disease onset.
Asunto(s)
Estudios de Asociación Genética , Glicina-ARNt Ligasa/genética , Glicina-ARNt Ligasa/metabolismo , Mutación , Enfermedades del Sistema Nervioso/genética , Enfermedades del Sistema Nervioso/metabolismo , Secuencia de Aminoácidos , Aminoacilación , Animales , Enfermedad de Charcot-Marie-Tooth/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Secuencia Conservada , Análisis Mutacional de ADN , Femenino , Expresión Génica , Glicina-ARNt Ligasa/química , Humanos , Cinética , Masculino , Ratones , Neuronas/metabolismo , Linaje , Transporte de Proteínas , Levaduras/genética , Levaduras/metabolismoRESUMEN
BACKGROUND: Nausea and vomiting is one of the most common complications of pregnancy, affecting 50% to 80% of pregnant persons. Moreover, despite its prevalence, it remains a challenging condition to treat. Treatment often involves oral and intravenous medications with potential side effects, particularly when taken in combination. Capsaicin cream is proven to decrease nausea and vomiting in cyclic vomiting syndrome; however, its use has not been well studied among pregnant patients. OBJECTIVE: This study aimed to test the feasibility of the off-label use of capsaicin for the treatment of nausea and vomiting in pregnancy. STUDY DESIGN: This was a double-blinded randomized controlled trial of pregnant individuals in their first trimester of pregnancy seeking care at a tertiary care hospital for nausea and vomiting. Consenting participants were randomized to abdominal application of topical capsaicin vs placebo. All participants received intravenous hydration and metoclopramide. The primary outcome, total treatment time, was recorded for all participants. In addition, symptom severity was assessed every 30 minutes using a visual analog scale. Data were analyzed using the Wilcoxon rank-sum test for continuous variables and the Fisher exact test for binary variables. RESULTS: Of the 38 eligible individuals approached, 30 were randomized. There was a trend toward decreased mean treatment time in the capsaicin group compared with the placebo group (79.9 vs 97.3 minutes; P=.1). There was no significant difference in visual analog scale scores at any time point between groups. Furthermore, capsaicin was well tolerated, with only 1 individual requesting the medication be removed. CONCLUSION: This study demonstrated that capsaicin is an acceptable treatment of nausea and vomiting in pregnancy and additional explorations of its use as treatment are feasible. A larger randomized controlled trial is needed to determine the efficacy of capsaicin in this population.
Asunto(s)
Antieméticos , Embarazo , Femenino , Humanos , Antieméticos/efectos adversos , Capsaicina/efectos adversos , Proyectos Piloto , Vómitos/inducido químicamente , Vómitos/tratamiento farmacológico , Vómitos/prevención & control , Náusea/inducido químicamente , Náusea/tratamiento farmacológico , Náusea/prevención & controlRESUMEN
Background: Low-income women are less likely to breastfeed than high-income women. Technology-based interventions demonstrate promise in decreasing health disparities. We assessed whether increased use of breastfeeding smartphone applications (apps) impacts breastfeeding rates for low-income women. Materials and Methods: This is a secondary analysis of a randomized control trial (RCT), including nulliparous, low-income women. Women were randomized to one of two novel apps: control app containing digital breastfeeding handouts and BreastFeeding Friend (BFF), an interactive app containing on-demand breastfeeding educational and video content. App usage was securely tracked. The highest quartile of BFF and control app users were combined and compared to the lowest quartile of app users. The primary outcome was breastfeeding initiation. Secondary outcomes included breastfeeding outcomes and resource preferences through 6 months. Results: In the RCT, BFF and control app median uses were 15 (interquartile range [IQR] 4-24) and 9 (IQR 5-19) (p = 0.1), respectively. Breastfeeding initiation did not differ with app usage (84.1% in highest quartile versus 78.2% for lowest quartile; p = 0.5). Rates of sustained and exclusive breastfeeding through 6 months were similar between groups. Among both groups, smartphone apps were the most preferred breastfeeding resource at 6 weeks. Low quartile users also preferred alternative online breastfeeding resources: >50% of all users preferred technology-based breastfeeding resources. Conclusions: Increased usage of breastfeeding apps did not improve breastfeeding rates among low-income women. However, technology-based resources were the most preferred breastfeeding resource after hospital discharge, indicating ongoing development of technology-based interventions has potential to increase breastfeeding in this high-needs population. clinicaltrials.gov (NCT03167073).
Asunto(s)
Lactancia Materna , Aplicaciones Móviles , Cognición , Femenino , Humanos , Teléfono InteligenteRESUMEN
Crossing over during meiotic prophase I is required for sexual reproduction in mice and contributes to genome-wide genetic diversity. Here we report on the characterization of an N-ethyl-N-nitrosourea-induced, recessive allele called mei4, which causes sterility in both sexes owing to meiotic defects. In mutant spermatocytes, chromosomes fail to congress properly at the metaphase plate, leading to arrest and apoptosis before the first meiotic division. Mutant oocytes have a similar chromosomal phenotype but in vitro can undergo meiotic divisions and fertilization before arresting. During late meiotic prophase in mei4 mutant males, absence of cyclin dependent kinase 2 and mismatch repair protein association from chromosome cores is correlated with the premature separation of bivalents at diplonema owing to lack of chiasmata. We have identified the causative mutation, a transversion in the 5' splice donor site of exon 1 in the mouse ortholog of Human Enhancer of Invasion 10 (Hei10; also known as Gm288 in mouse and CCNB1IP1 in human), a putative B-type cyclin E3 ubiquitin ligase. Importantly, orthologs of Hei10 are found exclusively in deuterostomes and not in more ancestral protostomes such as yeast, worms, or flies. The cloning and characterization of the mei4 allele of Hei10 demonstrates a novel link between cell cycle regulation and mismatch repair during prophase I.
Asunto(s)
Proteínas de Ciclo Celular/genética , Intercambio Genético/genética , Profase Meiótica I/genética , Mutación , Ubiquitina-Proteína Ligasas/genética , Proteínas Adaptadoras Transductoras de Señales , Alelos , Animales , Disparidad de Par Base/genética , Bovinos , Proteínas de Ciclo Celular/fisiología , Quinasa 2 Dependiente de la Ciclina/deficiencia , Quinasa 2 Dependiente de la Ciclina/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Noqueados , Recombinación Genética , Ubiquitina-Proteína Ligasas/fisiologíaRESUMEN
This cross-sectional study investigates the association between parental health and flourishing among children aged 6 months to 5 years in the US.
RESUMEN
Gene therapy approaches are being deployed to treat recessive genetic disorders by restoring the expression of mutated genes. However, the feasibility of these approaches for dominantly inherited diseases - where treatment may require reduction in the expression of a toxic mutant protein resulting from a gain-of-function allele - is unclear. Here we show the efficacy of allele-specific RNAi as a potential therapy for Charcot-Marie-Tooth disease type 2D (CMT2D), caused by dominant mutations in glycyl-tRNA synthetase (GARS). A de novo mutation in GARS was identified in a patient with a severe peripheral neuropathy, and a mouse model precisely recreating the mutation was produced. These mice developed a neuropathy by 3-4 weeks of age, validating the pathogenicity of the mutation. RNAi sequences targeting mutant GARS mRNA, but not wild-type, were optimized and then packaged into AAV9 for in vivo delivery. This almost completely prevented the neuropathy in mice treated at birth. Delaying treatment until after disease onset showed modest benefit, though this effect decreased the longer treatment was delayed. These outcomes were reproduced in a second mouse model of CMT2D using a vector specifically targeting that allele. The effects were dose dependent, and persisted for at least 1 year. Our findings demonstrate the feasibility of AAV9-mediated allele-specific knockdown and provide proof of concept for gene therapy approaches for dominant neuromuscular diseases.
Asunto(s)
Enfermedad de Charcot-Marie-Tooth/terapia , Terapia Genética , Glicina-ARNt Ligasa/genética , Interferencia de ARN , Alelos , Animales , Modelos Animales de Enfermedad , Células HEK293 , Humanos , Ratones , MutaciónRESUMEN
OBJECTIVE: To determine the genetic cause of neurodegeneration in a family with myeloneuropathy. METHODS: We studied 5 siblings in a family with a mild, dominantly inherited neuropathy by clinical examination and electrophysiology. One patient had a sural nerve biopsy. After ruling out common genetic causes of axonal Charcot-Marie-Tooth disease, we sequenced 3 tRNA synthetase genes associated with neuropathy. RESULTS: All affected family members had a mild axonal neuropathy, and 3 of 4 had lower extremity hyperreflexia, evidence of a superimposed myelopathy. A nerve biopsy showed evidence of chronic axonal loss. All affected family members had a heterozygous missense mutation c.304G>C (p.Gly102Arg) in the alanyl-tRNA synthetase (AARS) gene; this allele was not identified in unaffected individuals or control samples. The equivalent change in the yeast ortholog failed to complement a strain of yeast lacking AARS function, suggesting that the mutation is damaging. CONCLUSION: A novel mutation in AARS causes a mild myeloneuropathy, a novel phenotype for patients with mutations in one of the tRNA synthetase genes.
Asunto(s)
Alanina-ARNt Ligasa/genética , Enfermedad de Charcot-Marie-Tooth/genética , Mutación , Adulto , Axones/ultraestructura , Familia , Femenino , Genes Dominantes , Humanos , Masculino , Persona de Mediana Edad , Linaje , Nervio Sural/ultraestructura , Adulto JovenRESUMEN
Dominant optic atrophy (DOA) and axonal peripheral neuropathy (Charcot-Marie-Tooth type 2, or CMT2) are hereditary neurodegenerative disorders most commonly caused by mutations in the canonical mitochondrial fusion genes OPA1 and MFN2, respectively. In yeast, homologs of OPA1 (Mgm1) and MFN2 (Fzo1) work in concert with Ugo1, for which no human equivalent has been identified thus far. By whole-exome sequencing of patients with optic atrophy and CMT2, we identified four families with recessive mutations in SLC25A46. We demonstrate that SLC25A46, like Ugo1, is a modified carrier protein that has been recruited to the outer mitochondrial membrane and interacts with the inner membrane remodeling protein mitofilin (Fcj1). Loss of function in cultured cells and in zebrafish unexpectedly leads to increased mitochondrial connectivity, while severely affecting the development and maintenance of neurons in the fish. The discovery of SLC25A46 strengthens the genetic overlap between optic atrophy and CMT2 while exemplifying a new class of modified solute transporters linked to mitochondrial dynamics.
Asunto(s)
Predisposición Genética a la Enfermedad/genética , Proteínas Mitocondriales/genética , Mutación , Atrofia Óptica Autosómica Dominante/genética , Proteínas de Transporte de Fosfato/genética , Animales , Animales Modificados Genéticamente , Células COS , Enfermedad de Charcot-Marie-Tooth/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Chlorocebus aethiops , Embrión no Mamífero/embriología , Embrión no Mamífero/metabolismo , Embrión no Mamífero/ultraestructura , Exoma/genética , Femenino , Células HEK293 , Humanos , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Microscopía Confocal , Microscopía Electrónica de Transmisión , Membranas Mitocondriales/metabolismo , Proteínas Mitocondriales/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Atrofia Óptica Autosómica Dominante/metabolismo , Atrofia Óptica Autosómica Dominante/patología , Linaje , Proteínas de Transporte de Fosfato/metabolismo , Unión Proteica , Interferencia de ARN , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Análisis de Secuencia de ADN , Pez Cebra/embriología , Pez Cebra/metabolismoRESUMEN
Charcot-Marie-Tooth (CMT) disease is a clinically and genetically heterogeneous distal symmetric polyneuropathy. Whole-exome sequencing (WES) of 40 individuals from 37 unrelated families with CMT-like peripheral neuropathy refractory to molecular diagnosis identified apparent causal mutations in â¼ 45% (17/37) of families. Three candidate disease genes are proposed, supported by a combination of genetic and in vivo studies. Aggregate analysis of mutation data revealed a significantly increased number of rare variants across 58 neuropathy-associated genes in subjects versus controls, confirmed in a second ethnically discrete neuropathy cohort, suggesting that mutation burden potentially contributes to phenotypic variability. Neuropathy genes shown to have highly penetrant Mendelizing variants (HPMVs) and implicated by burden in families were shown to interact genetically in a zebrafish assay exacerbating the phenotype established by the suppression of single genes. Our findings suggest that the combinatorial effect of rare variants contributes to disease burden and variable expressivity.
Asunto(s)
Enfermedad de Charcot-Marie-Tooth/genética , Exoma , Carga Genética , Enfermedades del Sistema Nervioso Periférico/genética , Fenotipo , Animales , Femenino , Variación Genética , Proteínas del Choque Térmico HSP40/genética , Humanos , Masculino , Mutación , Proteína P2 de Mielina/genética , Linaje , Penetrancia , Serina C-Palmitoiltransferasa/genética , Supresión Genética , Pez CebraRESUMEN
Mammalian male fertility relies on complex inter- and intracellular signaling during spermatogenesis. Here we describe three alleles of the widely expressed A-kinase anchoring protein 9 (Akap9) gene, all of which cause gametogenic failure and infertility in the absence of marked somatic phenotypes. Akap9 disruption does not affect spindle nucleation or progression of prophase I of meiosis but does inhibit maturation of Sertoli cells, which continue to express the immaturity markers anti-Mullerian hormone and thyroid hormone receptor alpha in adults and fail to express the maturation marker p27(Kip1). Furthermore, gap and tight junctions essential for blood-testis barrier (BTB) organization are disrupted. Connexin43 (Cx43) and zona occludens-1 are improperly localized in Akap9 mutant testes, and Cx43 fails to compartmentalize germ cells near the BTB. These results identify and support a novel reproductive tissue-specific role for Akap9 in the coordinated regulation of Sertoli cells in the testis.
Asunto(s)
Proteínas de Anclaje a la Quinasa A/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Células de Sertoli/citología , Espermatogénesis/genética , Proteínas de Anclaje a la Quinasa A/genética , Animales , Hormona Antimülleriana/genética , Hormona Antimülleriana/metabolismo , Conexina 43/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Uniones Comunicantes/ultraestructura , Masculino , Meiosis/genética , Ratones , Ratones Mutantes , Proteínas Asociadas a Microtúbulos/genética , Especificidad de Órganos , Transporte de Proteínas , Células de Sertoli/metabolismo , Espermatozoides/citología , Espermatozoides/metabolismo , Huso Acromático/metabolismo , Receptores alfa de Hormona Tiroidea/genética , Receptores alfa de Hormona Tiroidea/metabolismo , Uniones Estrechas/ultraestructura , Proteína de la Zonula Occludens-1/metabolismoRESUMEN
ET-743 (trabectedin; Yondelis) is approved in Europe for the treatment of soft tissue sarcomas. Emerging phase 1 and 2 clinical data have shown high response rates in myxoid liposarcoma in part owing to the inhibition of the FUS-CHOP transcription factor. In this report, we show that modulation of specific oncogenic transcription factors by ET-743 may extend to other tumor types. We demonstrate that, among a panel of pediatric sarcomas, Ewing sarcoma family of tumors (ESFTs) cell lines bearing the EWS-FLI1 transcription factor are the most sensitive to treatment with ET-743 compared with osteosarcoma, rhabdomyosarcoma, and synovial sarcoma. We show that ET-743 reverses a gene signature of induced downstream targets of EWS-FLI1 in two different ESFT cell lines (P = .001). In addition, ET-743 directly suppresses the promoter activity of a known EWS-FLI1 downstream target NR0B1 luciferase reporter construct without changing the activity of a constitutively active control in ESFT cells. Furthermore, the effect is specific to EWS-FLI1, as forced expression of EWS-FLI1 in a cell type that normally lacks this fusion protein, HT1080 cells, induces the same NR0B1 promoter, but this activation is completely blocked by ET-743 treatment. Finally, we used gene set enrichment analysis to confirm that other mechanisms of ET-743 are active in ESFT cells. These results suggest a particular role for ET-743 in the treatment of translocation-positive tumors. In addition, the modulation of EWS-FLI1 makes it a novel targeting agent for ESFT and suggests that further development of this compound for the treatment of ESFT is warranted.