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BACKGROUND: Fabry disease (FD) is a rare X-linked lysosomal disorder caused by alpha-galactosidase deficiency consecutive to a pathogenic variant in the GLA gene. Age at onset is highly variable, with a wide clinical spectrum including frequent renal, cardiac, skin and nervous system manifestations. Since pain can be an indicator of underlying FD, we wanted to estimate the prevalence of FD in a population of chronic pain patients. METHODS: Two studies, DOUFAB and DOUFABIS, were carried out in expert centers for chronic pain to assess the prevalence of FD by measuring alpha galactosidase A activity in men and analysing the GLA gene in women. RESULTS: Analysis of 893 patients, essentially adults, led to the diagnosis of FD in one female patient, now treated with enzyme replacement therapy. CONCLUSIONS: The prevalence of FD is estimated about 1/1000 in our population of men and women suffering from various chronic pain. This is nearly the prevalence of FD observed in other previously screened high-risk populations with renal failure. SIGNIFICANCE: Although a systematic search for FD does not seem relevant in the context of unexplained chronic pain in adults, a positive family history of FD or the presence of additional FD related organ features must lead to consider this rare disease diagnosis. Therefore, pain specialists need to be aware of main features of FD, including pain characteristics.
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OBJECTIVE: Prenatal exome sequencing (pES) is now commonly used in clinical practice. It can be used to identifiy an additional diagnosis in around 30% of fetuses with structural defects and normal chromosomal microarray analysis (CMA). However, interpretation remains challenging due to the limited prenatal data for genetic disorders. METHOD: We conducted an ancillary study including fetuses with pathogenic/likely pathogenic variants identified by trio-pES from the "AnDDI-Prenatome" study. The prenatal phenotype of each patient was categorized as typical, uncommon, or unreported based on the comparison of the prenatal findings with documented findings in the literature and public phenotype-genotype databases (ClinVar, HGMD, OMIM, and Decipher). RESULTS: Prenatal phenotypes were typical for 38/56 fetuses (67.9%). For the others, genotype-phenotype associations were challenging due to uncommon prenatal features (absence of recurrent hallmark, rare, or unreported). We report the first prenatal features associated with LINS1 and PGM1 variants. In addition, a double diagnosis was identified in three fetuses. CONCLUSION: Standardizing the description of prenatal features, implementing longitudinal prenatal follow-up, and large-scale collection of prenatal features are essential steps to improving pES data interpretation.
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BACKGROUND: SCN5A variants are associated with a spectrum of cardiac electrical disorders with clear phenotypes. However, they may also be associated with complex phenotypic traits like overlap syndromes, or pleiotropy, which have not been systematically described. Additionally, the involvement of SCN5A in dilated cardiomyopathies (DCM) remains controversial. OBJECTIVE: We aimed to (1) evaluate the different phenotypes associated with pathogenic (P)/likely pathogenic (LP) SCN5A variants and (2) determine the prevalence of pleiotropy in a large multicentric cohort of P/LP SCN5A variant carriers. METHODS: The DNA of 13,510 consecutive probands (9960 with cardiomyopathies) was sequenced using a custom panel of genes. Individuals carrying a heterozygous single P/LP SCN5A variant were selected and phenotyped. RESULTS: The study included 170 P/LP variants found in 495 patients. Among them, 119 (70%) were exclusively associated with a single well-established phenotype: 91 with Brugada syndrome, 15 with type 3 long QT syndrome, six with progressive cardiac conduction disease, four with multifocal ectopic Purkinje-related premature contraction, and three with sick sinus syndrome. Thirty-two variants (19%) were associated with overlap syndromes and/or pleiotropy. The 19 remaining variants (11%) were associated with atypical or unclear phenotypes. Among those, eight were carried by eight patients presenting with DCM with a debatable causative genotype/phenotype link. CONCLUSION: Most P/LP SCN5A variants were found in patients with primary electrical disorders, mainly Brugada syndrome. Nearly 20% were associated with overlap syndromes or pleiotropy, underscoring the need for comprehensive phenotypic evaluation. The concept of SCN5A variants causing DCM is extremely rare (8/9960), if not questionable.
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Xq28 int22h-1/int22h-2 duplication is the result of non-allelic homologous recombination between int22h-1/int22h-2 repeats separated by 0.5 Mb. It is responsible for a syndromic form of intellectual disability (ID), with recurrent infections and atopic diseases. Minor defects, nonspecific facial dysmorphic features, and overweight have also been described. Half of female carriers have been reported with ID, whereas all reported evaluated born males present mild to moderate ID, suggesting complete penetrance. We collected data on 15 families from eight university hospitals. Among them, 40 patients, 21 females (one fetus), and 19 males (two fetuses), were carriers of typical or atypical Xq28 int22h-1/int22h-2 duplication. Twenty-one individuals were considered asymptomatic (16 females and 5 males), without significantly higher rate of recurrent infections, atopia, overweight, or facial dysmorphism. Approximately 67% live-born males and 23% live-born female carriers of the typical duplication did not have obvious signs of intellectual disability, suggesting previously undescribed incomplete penetrance or low expression in certain carriers. The possibility of a second-hit or modifying factors to this possible susceptibility locus is yet to be studied but a possible observational bias should be considered in assessing such challenging X-chromosome copy number gains. Additional segregation studies should help to quantify this newly described incomplete penetrance.
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Cromosomas Humanos X , Discapacidad Intelectual , Penetrancia , Humanos , Masculino , Femenino , Cromosomas Humanos X/genética , Discapacidad Intelectual/genética , Niño , Adulto , Adolescente , Preescolar , Fenotipo , Duplicación Cromosómica/genética , Duplicación de Gen , Linaje , Adulto JovenRESUMEN
Cat Eye Syndrome (CES) is a rare genetic disease caused by the presence of a small supernumerary marker chromosome derived from chromosome 22, which results in a partial tetrasomy of 22p-22q11.21. CES is classically defined by association of iris coloboma, anal atresia, and preauricular tags or pits, with high clinical and genetic heterogeneity. We conducted an international retrospective study of patients carrying genomic gain in the 22q11.21 chromosomal region upstream from LCR22-A identified using FISH, MLPA, and/or array-CGH. We report a cohort of 43 CES cases. We highlight that the clinical triad represents no more than 50% of cases. However, only 16% of CES patients presented with the three signs of the triad and 9% not present any of these three signs. We also highlight the importance of other impairments: cardiac anomalies are one of the major signs of CES (51% of cases), and high frequency of intellectual disability (47%). Ocular motility defects (45%), abdominal malformations (44%), ophthalmologic malformations (35%), and genitourinary tract defects (32%) are other frequent clinical features. We observed that sSMC is the most frequent chromosomal anomaly (91%) and we highlight the high prevalence of mosaic cases (40%) and the unexpectedly high prevalence of parental transmission of sSMC (23%). Most often, the transmitting parent has mild or absent features and carries the mosaic marker at a very low rate (<10%). These data allow us to better delineate the clinical phenotype associated with CES, which must be taken into account in the cytogenetic testing for this syndrome. These findings draw attention to the need for genetic counseling and the risk of recurrence.
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Aneuploidia , Trastornos de los Cromosomas , Cromosomas Humanos Par 22 , Anomalías del Ojo , Cardiopatías Congénitas , Humanos , Estudios Retrospectivos , Hibridación Fluorescente in Situ , Cromosomas Humanos Par 22/genética , Cardiopatías Congénitas/genéticaRESUMEN
BACKGROUND: Few clinical data are available on NEXN mutation carriers, and the gene's involvement in cardiomyopathies or sudden death has not been fully established. Our objectives were to assess the prevalence of putative pathogenic variants in NEXN and to describe the phenotype and prognosis of patients carrying the variants. METHODS: DNA samples from consecutive patients with cardiomyopathy or sudden cardiac death/sudden infant death syndrome/idiopathic ventricular fibrillation were sequenced with a custom panel of genes. Index cases carrying at least one putative pathogenic variant in the NEXN gene were selected. RESULTS: Of the 9516 index patients sequenced, 31 were carriers of a putative pathogenic variant in NEXN only, including 2 with double variants and 29 with a single variant. Of the 29 unrelated probands with a single variant (16 males; median age at diagnosis, 32.0 [26.0-49.0] years), 21 presented with dilated cardiomyopathy (prevalence, 0.33%), and 3 presented with hypertrophic cardiomyopathy (prevalence, 0.14%). Three patients had idiopathic ventricular fibrillation, and there were 2 cases of sudden infant death syndrome (prevalence, 0.46%). For patients with dilated cardiomyopathy, the median left ventricle ejection fraction was 37.5% (26.25-50.0) at diagnosis and improved with treatment in 13 (61.9%). Over a median follow-up period of 6.0 years, we recorded 3 severe arrhythmic events and 2 severe hemodynamic events. CONCLUSIONS: Putative pathogenic NEXN variants were mainly associated with dilated cardiomyopathy; in these individuals, the prognosis appeared to be relatively good. However, severe and early onset phenotypes were also observed-especially in patients with double NEXN variants. We also detected NEXN variants in patients with hypertrophic cardiomyopathy and sudden infant death syndrome/idiopathic ventricular fibrillation, although a causal link could not be established.
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Cardiomiopatías , Cardiomiopatía Dilatada , Cardiomiopatía Hipertrófica , Muerte Súbita del Lactante , Fibrilación Ventricular , Masculino , Lactante , Humanos , Adulto , Persona de Mediana Edad , Cardiomiopatía Dilatada/genética , Prevalencia , Cardiomiopatías/diagnóstico , Fenotipo , Cardiomiopatía Hipertrófica/genética , Cardiomiopatía Hipertrófica/complicaciones , Muerte Súbita Cardíaca/etiología , Pronóstico , Proteínas de Microfilamentos/genéticaRESUMEN
Cardiomyopathies are diseases of the heart muscle with variable clinical expressivity. Most of forms are inherited as dominant trait, and with incomplete penetrance until adulthood. Severe forms of cardiomyopathies were observed during the antenatal period with a pejorative issue leading to fetal death or medical interruption of pregnancy. Variable phenotypes and genetic heterogeneity make etiologic diagnosis difficult. We report 11 families (16 cases) whose unborn, newborn or infant with early onset cardiomyopathies. Detailed morphological and histological examinations of hearts were implemented, as well as genetic analysis on a cardiac targeted NGS panel. This strategy allowed the identification of the genetic cause of the cardiomyopathy in 8/11 families. Compound heterozygous mutations in dominant adulthood cardiomyopathy genes were found in two, pathogenic variants in co-dominant genes in one, de novo mutations in 5 including a germline mosaicism in one family. Parental testing was systematically performed to detect mutation carriers, and to manage cardiological surveillance and propose a genetic counseling. This study highlights the great diagnostic value of the genetic testing of severe antenatal cardiomyopathy both for genetic counseling and to detect presymptomatic parents at higher risk of developing cardiomyopathy.
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Cardiomiopatías , Embarazo , Humanos , Femenino , Cardiomiopatías/diagnóstico , Pruebas Genéticas , Mutación , Fenotipo , Asesoramiento GenéticoRESUMEN
Introduction: Prenatal ultrasound (US) anomalies are detected in around 5%-10% of pregnancies. In prenatal diagnosis, exome sequencing (ES) diagnostic yield ranges from 6% to 80% depending on the inclusion criteria. We describe the first French national multicenter pilot study aiming to implement ES in prenatal diagnosis following the detection of anomalies on US. Patients and methods: We prospectively performed prenatal trio-ES in 150 fetuses with at least two US anomalies or one US anomaly known to be frequently linked to a genetic disorder. Trio-ES was only performed if the results could influence pregnancy management. Chromosomal microarray (CMA) was performed before or in parallel. Results: A causal diagnosis was identified in 52/150 fetuses (34%) with a median time to diagnosis of 28 days, which rose to 56/150 fetuses (37%) after additional investigation. Sporadic occurrences were identified in 34/56 (60%) fetuses and unfavorable vital and/or neurodevelopmental prognosis was made in 13/56 (24%) fetuses. The overall diagnostic yield was 41% (37/89) with first-line trio-ES versus 31% (19/61) after normal CMA. Trio-ES and CMA were systematically concordant for identification of pathogenic CNV. Conclusion: Trio-ES provided a substantial prenatal diagnostic yield, similar to postnatal diagnosis with a median turnaround of approximately 1 month, supporting its routine implementation during the detection of prenatal US anomalies.
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OBJECTIVE: We aimed to gather fetal cases carrying a 7q11.23 copy number variation (CNV) and collect precise clinical data to broaden knowledge of antenatal features in these syndromes. METHODS: We retrospectively recruited unrelated cases with 7q11.23 deletion, known as Williams-Beuren syndrome (WBS), or 7q11.23 duplication who had prenatal ultrasound findings. We collected laboratory and clinical data, fetal ultrasound, cardiac ultrasound and fetal autopsy reports from 18 prenatal diagnostic centers throughout France. RESULTS: 40 fetuses with WBS were collected and the most common features were intra-uterine growth retardation (IUGR) (70.0%, 28/40), cardiovascular defects (30.0%, 12/40), polyhydramnios (17.5%, 7/40) and protruding tongue (15.0%, 6/40). Fetal autopsy reports were available for 11 cases and were compared with ultrasound prenatal features. Four cases of fetuses with 7q11.23 microduplication were collected and prenatal ultrasound signs were variable and often isolated. CONCLUSION: This work strengthens the fact that 7q11.23 CNVs are associated with a broad spectrum of antenatal presentations. IUGR and cardiovascular defects were the most frequent ultrasound signs. By reporting the biggest series of antenatal WBS, we aim to better delineate distinctive signs in fetuses with 7q11.23 CNVs.
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Síndrome de Williams , Humanos , Femenino , Embarazo , Síndrome de Williams/diagnóstico por imagen , Síndrome de Williams/genética , Síndrome de Williams/complicaciones , Variaciones en el Número de Copia de ADN , Estudios Retrospectivos , Retardo del Crecimiento Fetal , UltrasonografíaRESUMEN
OBJECTIVES: The management for isolated increased nuchal translucency (NT) in the first trimester with a normal karyotype and normal Chromosomal Microarray Analysis (CMA) is not consensual. The aim was to perform a survey among the Pluridisciplinary Centers for Prenatal Diagnosis (CPDPN) in France regarding their management of increased NT in the first trimester. METHODS: We conducted a multicenter descriptive survey between September 2021 and October 2021 among the 46 CPDPNs of France. RESULTS: The response rate was 56.5% (n = 26/46). The NT thickness threshold for which invasive diagnosis testing is performed is 3.0mm in 23.1% of centers (n = 6/26) and 3.5mm in 76.9% of centers (n = 20/26). A CMA was performed alone in 26.9% of centers (n = 7/26) while 7.7% of centers (n = 2/26) did not perform a CMA. The gestational age for the first reference ultrasound scan was 16 to 18 WG in 88.5% of centers (n = 23/26), while it was not performed before 22 WG in 11.5% of centers (n = 3/26). Fetal echocardiography is proposed systematically in 73.1% of centers (n = 19/26). CONCLUSION: There is heterogeneity in the management of increased NT in the first trimester among the CPDPNs in France. In case of increased NT on first trimester ultrasound scan, the NT thickness threshold for which invasive diagnosis testing is performed varies from 3.0 mm or 3.5mm depending on the center. Moreover, CMA and early reference morphological ultrasound scan between 16 and 18 WG were not systematically performed, despite the current data suggesting their interest.
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Medida de Translucencia Nucal , Diagnóstico Prenatal , Embarazo , Femenino , Humanos , Primer Trimestre del Embarazo , Edad Gestacional , Análisis por Micromatrices , Ultrasonografía PrenatalRESUMEN
A single missense variant of the TMPO/LAP2α gene, encoding LAP2 proteins, has been associated with cardiomyopathy in two brothers. To further evaluate its role in cardiac muscle, we included TMPO in our cardiomyopathy diagnostic gene panel. A screening of ~5000 patients revealed three novel rare TMPO heterozygous variants in six males diagnosed with hypertrophic or dilated cardiomypathy. We identified in different cellular models that (1) the frameshift variant LAP2α p.(Gly395Glufs*11) induced haploinsufficiency, impeding cell proliferation and/or producing a truncated protein mislocalized in the cytoplasm; (2) the C-ter missense variant LAP2α p.(Ala240Thr) led to a reduced proximity events between LAP2α and the nucleosome binding protein HMGN5; and (3) the LEM-domain missense variant p.(Leu124Phe) decreased both associations of LAP2α/ß with the chromatin-associated protein BAF and inhibition of the E2F1 transcription factor activity which is known to be dependent on Rb, partner of LAP2α. Additionally, the LAP2α expression was lower in the left ventricles of male mice compared to females. In conclusion, our study reveals distinct altered properties of LAP2 induced by these TMPO/LAP2 variants, leading to altered cell proliferation, chromatin structure or gene expression-regulation pathways, and suggests a potential sex-dependent role of LAP2 in myocardial function and disease.
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Cardiomiopatías , Cromosomas , Femenino , Masculino , Ratones , Animales , Cardiomiopatías/genética , Cromatina , FenotipoRESUMEN
PURPOSE: Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the "ClinVar low-hanging fruit" reanalysis, reasons for the failure of previous analyses, and lessons learned. METHODS: Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. RESULTS: We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). CONCLUSION: The "ClinVar low-hanging fruit" analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock.
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Discapacidad Intelectual , Humanos , Secuenciación del Exoma , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Alelos , GenotipoRESUMEN
A small but growing body of scientific literature is emerging about clinical findings in patients with 19p13.3 microdeletion or duplication. Recently, a proximal 19p13.3 microduplication syndrome was described, associated with growth delay, microcephaly, psychomotor delay and dysmorphic features. The aim of our study was to better characterize the syndrome associated with duplications in the proximal 19p13.3 region (prox 19p13.3 dup), and to propose a comprehensive analysis of the underlying genomic mechanism. We report the largest cohort of patients with prox 19p13.3 dup through a collaborative study. We collected 24 new patients with terminal or interstitial 19p13.3 duplication characterized by array-based Comparative Genomic Hybridization (aCGH). We performed mapping, phenotype-genotype correlations analysis, critical region delineation and explored three-dimensional chromatin interactions by analyzing Topologically Associating Domains (TADs). We define a new 377 kb critical region (CR 1) in chr19: 3,116,922-3,494,377, GRCh37, different from the previously described critical region (CR 2). The new 377 kb CR 1 includes a TAD boundary and two enhancers whose common target is PIAS4. We hypothesize that duplications of CR 1 are responsible for tridimensional structural abnormalities by TAD disruption and misregulation of genes essentials for the control of head circumference during development, by breaking down the interactions between enhancers and the corresponding targeted gene.
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Anomalías Múltiples , Microcefalia , Humanos , Hibridación Genómica Comparativa , Anomalías Múltiples/genética , Microcefalia/genética , Síndrome , Estudios de Asociación GenéticaRESUMEN
BACKGROUND: Oculo-auriculo-vertebral spectrum (OAVS) is the second most common cause of head and neck malformations in children after orofacial clefts. OAVS is clinically heterogeneous and characterised by a broad range of clinical features including ear anomalies with or without hearing loss, hemifacial microsomia, orofacial clefts, ocular defects and vertebral abnormalities. Various genetic causes were associated with OAVS and copy number variations represent a recurrent cause of OAVS, but the responsible gene often remains elusive. METHODS: We described an international cohort of 17 patients, including 10 probands and 7 affected relatives, presenting with OAVS and carrying a 14q22.3 microduplication detected using chromosomal microarray analysis. For each patient, clinical data were collected using a detailed questionnaire addressed to the referring clinicians. We subsequently studied the effects of OTX2 overexpression in a zebrafish model. RESULTS: We defined a 272 kb minimal common region that only overlaps with the OTX2 gene. Head and face defects with a predominance of ear malformations were present in 100% of patients. The variability in expressivity was significant, ranging from simple chondromas to severe microtia, even between intrafamilial cases. Heterologous overexpression of OTX2 in zebrafish embryos showed significant effects on early development with alterations in craniofacial development. CONCLUSIONS: Our results indicate that proper OTX2 dosage seems to be critical for the normal development of the first and second branchial arches. Overall, we demonstrated that OTX2 genomic duplications are a recurrent cause of OAVS marked by auricular malformations of variable severity.
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Labio Leporino , Fisura del Paladar , Síndrome de Goldenhar , Humanos , Animales , Síndrome de Goldenhar/genética , Pez Cebra/genética , Variaciones en el Número de Copia de ADN/genética , Factores de Transcripción Otx/genéticaRESUMEN
Oculo-auriculo-vertebral spectrum (OAVS) or Goldenhar syndrome is due to an abnormal development of first and second branchial arches derivatives during embryogenesis and is characterised by hemifacial microsomia associated with auricular, ocular and vertebral malformations. The clinical and genetic heterogeneity of this spectrum with incomplete penetrance and variable expressivity, render its molecular diagnosis difficult. Only a few recurrent CNVs and genes have been identified as causatives in this complex disorder so far. Prenatal environmental causal factors have also been hypothesised. However, most of the patients remain without aetiology. In this review, we aim at updating clinical diagnostic criteria and describing genetic and non-genetic aetiologies, animal models as well as novel diagnostic tools and surgical management, in order to help and improve clinical care and genetic counselling of these patients and their families.
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Síndrome de Goldenhar , Animales , Región Branquial , Variaciones en el Número de Copia de ADN , Síndrome de Goldenhar/diagnóstico , Síndrome de Goldenhar/genética , HumanosRESUMEN
The vertebrate left-right axis is specified during embryogenesis by a transient organ: the left-right organizer (LRO). Species including fish, amphibians, rodents and humans deploy motile cilia in the LRO to break bilateral symmetry, while reptiles, birds, even-toed mammals and cetaceans are believed to have LROs without motile cilia. We searched for genes whose loss during vertebrate evolution follows this pattern and identified five genes encoding extracellular proteins, including a putative protease with hitherto unknown functions that we named ciliated left-right organizer metallopeptide (CIROP). Here, we show that CIROP is specifically expressed in ciliated LROs. In zebrafish and Xenopus, CIROP is required solely on the left side, downstream of the leftward flow, but upstream of DAND5, the first asymmetrically expressed gene. We further ascertained 21 human patients with loss-of-function CIROP mutations presenting with recessive situs anomalies. Our findings posit the existence of an ancestral genetic module that has twice disappeared during vertebrate evolution but remains essential for distinguishing left from right in humans.
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Evolución Biológica , Tipificación del Cuerpo , Redes Reguladoras de Genes , Metaloproteasas , Animales , Humanos , Tipificación del Cuerpo/genética , Tipificación del Cuerpo/fisiología , Cilios/genética , Mutación con Pérdida de Función , Metaloproteasas/genética , Metaloproteasas/fisiología , Proteínas/genética , Proteínas/fisiología , Vertebrados/genéticaRESUMEN
The stable insertion of the retroviral genome into the host chromosomes requires the association between integration complexes and cellular chromatin via the interaction between retroviral integrase and the nucleosomal target DNA. This final association may involve the chromatin-binding properties of both the retroviral integrase and its cellular cofactor LEDGF/p75. To investigate this and better understand the LEDGF/p75-mediated chromatin tethering of HIV-1 integrase, we used a combination of biochemical and chromosome-binding assays. Our study revealed that retroviral integrase has an intrinsic ability to bind and recognize specific chromatin regions in metaphase even in the absence of its cofactor. Furthermore, this integrase chromatin-binding property was modulated by the interaction with its cofactor LEDGF/p75, which redirected the enzyme to alternative chromosome regions. We also better determined the chromatin features recognized by each partner alone or within the functional intasome, as well as the chronology of efficient LEDGF/p75-mediated targeting of HIV-1 integrase to chromatin. Our data support a new chromatin-binding function of integrase acting in concert with LEDGF/p75 for the optimal association with the nucleosomal substrate. This work also provides additional information about the behavior of retroviral integration complexes in metaphase chromatin and the mechanism of action of LEDGF/p75 in this specific context.
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Proteínas Adaptadoras Transductoras de Señales/genética , Cromatina/metabolismo , Integrasa de VIH/genética , Histonas/genética , Interacciones Huésped-Patógeno/genética , Factores de Transcripción/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Cromatina/química , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Regulación de la Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Integrasa de VIH/metabolismo , Histonas/metabolismo , Humanos , Células K562 , Cultivo Primario de Células , Unión Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transducción de Señal , Linfocitos T/metabolismo , Linfocitos T/virología , Factores de Transcripción/metabolismoRESUMEN
Hereditary spastic paraplegias (HSP) are heterogeneous disorders, with more than 70 causative genes. Variants in SPAST are the most frequent genetic etiology and are responsible for spastic paraplegia type 4 (SPG4). Age at onset can vary, even between patients from the same family, and incomplete penetrance is described. Somatic mosaicism is extremely rare with only three patients reported in the literature. We report here SPAST mosaic variants in four unrelated patients. We confirm that mosaicism in SPAST is a very rare event with only four identified cases on more than 300 patients with a SPAST variant previously described by our clinical diagnostic laboratory.
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Heterocigoto , Mosaicismo , Mutación , Paraplejía Espástica Hereditaria/diagnóstico , Paraplejía Espástica Hereditaria/genética , Espastina/genética , Alelos , Niño , Hibridación Genómica Comparativa , Femenino , Francia , Frecuencia de los Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Linaje , FenotipoRESUMEN
Goldenhar syndrome or oculo-auriculo-vertebral spectrum (OAVS) is a complex developmental disorder characterized by asymmetric ear anomalies, hemifacial microsomia, ocular and vertebral defects. We aimed at identifying and characterizing a new gene associated with OAVS. Two affected brothers with OAVS were analyzed by exome sequencing that revealed a missense variant (p.(Asn358Ser)) in the EYA3 gene. EYA3 screening was then performed in 122 OAVS patients that identified the same variant in one individual from an unrelated family. Segregation assessment in both families showed incomplete penetrance and variable expressivity. We investigated this variant in cellular models to determine its pathogenicity and demonstrated an increased half-life of the mutated protein without impact on its ability to dephosphorylate H2AFX following DNA repair pathway induction. Proteomics performed on this cellular model revealed four significantly predicted upstream regulators which are PPARGC1B, YAP1, NFE2L2 and MYC. Moreover, eya3 knocked-down zebrafish embryos developed specific craniofacial abnormalities corroborating previous animal models and supporting its involvement in the OAVS. Additionally, EYA3 gene expression was deregulated in vitro by retinoic acid exposure. EYA3 is the second recurrent gene identified to be associated with OAVS. Moreover, based on protein interactions and related diseases, we suggest the DNA repair as a key molecular pathway involved in craniofacial development.