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1.
Am J Hum Genet ; 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38776926

RESUMEN

Detection of structural variants (SVs) is currently biased toward those that alter copy number. The relative contribution of inversions toward genetic disease is unclear. In this study, we analyzed genome sequencing data for 33,924 families with rare disease from the 100,000 Genomes Project. From a database hosting >500 million SVs, we focused on 351 genes where haploinsufficiency is a confirmed disease mechanism and identified 47 ultra-rare rearrangements that included an inversion (24 bp to 36.4 Mb, 20/47 de novo). Validation utilized a number of orthogonal approaches, including retrospective exome analysis. RNA-seq data supported the respective diagnoses for six participants. Phenotypic blending was apparent in four probands. Diagnostic odysseys were a common theme (>50 years for one individual), and targeted analysis for the specific gene had already been performed for 30% of these individuals but with no findings. We provide formal confirmation of a European founder origin for an intragenic MSH2 inversion. For two individuals with complex SVs involving the MECP2 mutational hotspot, ambiguous SV structures were resolved using long-read sequencing, influencing clinical interpretation. A de novo inversion of HOXD11-13 was uncovered in a family with Kantaputra-type mesomelic dysplasia. Lastly, a complex translocation disrupting APC and involving nine rearranged segments confirmed a clinical diagnosis for three family members and resolved a conundrum for a sibling with a single polyp. Overall, inversions play a small but notable role in rare disease, likely explaining the etiology in around 1/750 families across heterogeneous clinical cohorts.

2.
Front Immunol ; 14: 1287258, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38115997

RESUMEN

ISG15 deficiency is a rare disease caused by autosomal recessive variants in the ISG15 gene, which encodes the ISG15 protein. The ISG15 protein plays a dual role in both the type I and II interferon (IFN) immune pathways. Extracellularly, the ISG15 protein is essential for IFN-γ-dependent anti-mycobacterial immunity, while intracellularly, ISG15 is necessary for USP18-mediated downregulation of IFN-α/ß signalling. Due to this dual role, ISG15 deficiency can present with various clinical phenotypes, ranging from susceptibility to mycobacterial infection to autoinflammation characterised by necrotising skin lesions, intracerebral calcification, and pulmonary involvement. In this report, we describe novel variants found in two different families that result in complete ISG15 deficiency and severe skin ulceration. Whole exome sequencing identified a heterozygous missense p.Q16X ISG15 variant and a heterozygous multigene 1p36.33 deletion in the proband from the first family. In the second family, a homozygous total ISG15 gene deletion was detected in two siblings. We also conducted further analysis, including characterisation of cytokine dysregulation, interferon-stimulated gene expression, and p-STAT1 activation in lymphocytes and lesional tissue. Finally, we demonstrate the complete and rapid resolution of clinical symptoms associated with ISG15 deficiency in one sibling from the second family following treatment with the Janus kinase (JAK) inhibitor baricitinib.


Asunto(s)
Citocinas , Ubiquitinas , Humanos , Ubiquitinas/metabolismo , Citocinas/metabolismo , Interferones , Ubiquitina Tiolesterasa/genética , Ubiquitina Tiolesterasa/metabolismo
3.
Artículo en Inglés | MEDLINE | ID: mdl-38006337

RESUMEN

OBJECTIVE: Several monogenic autoinflammatory disorders and primary immunodeficiencies can present early in life with features that may be mistaken for Behçet's disease (BD). We aimed to develop a genetic analysis workflow to identify rare monogenic BD-like diseases and establish the contribution of HLA haplotype in a cohort of patients from the UK. METHODS: Patients with clinically suspected BD were recruited from four BD specialist care centres in the UK. All participants underwent whole exome sequencing (WES), and genetic analysis thereafter by 1. examining genes known to cause monogenic immunodeficiency, autoinflammation or vasculitis by virtual panel application; 2. scrutiny of variants prioritised by Exomiser using Human Phenotype Ontology (HPO); 3. identification of copy number variants using ExomeDepth; and 4. HLA-typing using OptiType. RESULTS: Thirty-one patients were recruited: median age 15 (4-52), and median disease onset age 5 (0-20). Nine/31 (29%) patients had monogenic disease mimicking BD: 5 cases of Haploinsufficiency of A20 with novel TNFAIP3 variants (p.T76I, p.M112Tfs*8, p.S548Dfs*128, p.C657Vfs*14, p.E661Nfs*36); 1 case of ISG15 deficiency with a novel nonsense variant (ISG15:p.Q16X) and 1p36.33 microdeletion; 1 case of Common variable immune deficiency (TNFRSF13B:p.A181E); and 2 cases of TNF receptor associated periodic syndrome (TNFRSF1A:p.R92Q). Of the remaining 22 patients, 8 (36%) were HLA-B*51 positive. CONCLUSION: We describe a novel genetic workflow for BD, which can efficiently detect known and potentially novel monogenic forms of BD, whilst additionally providing HLA-typing. Our results highlight the importance of genetic testing before BD diagnosis, since this has impact on choice of therapy, prognosis, and genetic counselling.

4.
Eur J Med Genet ; 66(8): 104788, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37295610

RESUMEN

Stüve-Wiedemann Syndrome (STWS) is an autosomal recessive condition caused by variants in the LIFR gene, presenting with respiratory failure, hyperthermia and skeletal dysplasia in the neonatal period. Historically identified as a lethal condition, more children are now managed holistically from early in life with multidisciplinary team involvement with improved outcomes. This stems from early diagnosis, supported by molecular testing in the pre and postnatal periods. This report includes five such cases with survival in childhood to 10 years old in the UK affected by skeletal abnormalities, hyperthermia, respiratory distress and their diagnostic odyssey. All cases have a molecular diagnosis; two patients (family 1) were found to be homozygous for a novel pathogenic LIFR variant NM_002310.5:c.704G > A, p.(Trp235Ter). One patient (family 2) is compound heterozygous with the previously reported LIFR variant NM_002310.5:c.756dup p.(Lys253Ter), and a second novel variant NM_002310.5:c.397+5G > A. Two patients (family 3) are homozygous for one of the same LIFR variants NM_002310.5:c.756dup p.(Lys253Ter) as in family 2. This report discusses genotypic and phenotypic data for five patients with STWS, as well as the need for multi-disciplinary, proactive management and genetic counselling.


Asunto(s)
Osteocondrodisplasias , Recién Nacido , Niño , Humanos , Lactante , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia/genética , Mutación , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genética , Reino Unido
5.
Eur J Med Genet ; 66(4): 104714, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36724812

RESUMEN

INTRODUCTION: Recurrent chromosome 16p13.11 microduplication has been characterised in the literature as a cause of developmental delay, learning difficulties and behavioural abnormalities. It is a neurosusceptibility locus and has incomplete penetrance and variable expression. Other clinical features, such as cardiac abnormalities have also been reported. The duplicated region contains the MYH11 gene, which encodes the protein myosin-11 and is a component of the myosin heavy chain in smooth muscle. Recent literature has suggested 16p13.11 microduplication as one of the possible risk factors for thoracic aortic aneurysms and dissection (TAAD). Therefore, we studied the detailed phenotype of cases of chromosome 16p13.11 microduplication from seven centres in the United Kingdom (UK) to expand the phenotype, focusing on the cardiac abnormalities. METHODS: All individuals with a chromosome 16p13.11 microduplication seen in Clinical Genetics prior to June 2017 in 6 centres (prior to 2018 in the seventh centre) were identified through the regional genetics laboratory databases. A Microsoft Excel® proforma was created and clinical data was collected retrospectively from clinical genetics databases from the seven genetics services in the UK. The data was collated and analysed collectively. RESULTS: The majority of the individuals presented with (72%) developmental delay and (62%) behavioural abnormalities, in keeping with the published literature. 27% had some dysmorphic features, 14% had visual impairment and 8% had congenital cardiac abnormalities. Echocardiograms were performed in 50% of patients, and only 3.8% patients had aortic dilatation and no one had aortic dissection. 9.7% of patients were found to have a second genetic/chromosomal diagnosis, especially where there were additional phenotypic features. CONCLUSION: 16p13.11 microduplication is a neurosusceptibility locus and is associated with variable expression. It may be helpful to refer children with 16p13.11 microduplication for a cardiac review for congenital cardiac abnormalities and also for ophthalmological assessment. Further prospective studies with cardiac assessments are recommended in this cohort of patients to determine whether ongoing aortic surveillance is indicated. Guidelines about the frequency of surveillance are indicated, especially in individuals with normal cardiac findings. We also highlight the importance of considering a second diagnosis if the phenotype is inconsistent with that reported.


Asunto(s)
Duplicación Cromosómica , Cromosomas Humanos Par 11 , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Fenotipo
7.
Pediatr Rheumatol Online J ; 20(1): 49, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35840971

RESUMEN

BACKGROUND: We report a three-year-old girl with a potentially unique phenotype of perinatal onset and neurovascular features who was found to have PAMI syndrome. We also compare her case to those previously reported and review the differences between the PSTPIP1-associated inflammatory diseases (PAID) phenotypes and genotypes. CASE PRESENTATION: The patient was found to have a heterozygous pathogenic variant in PSTPIP1 (c.748G > A p.E250K). This variant was shown to be absent in both parents and therefore de novo in the patient. A literature review was carried out through multiple databases using the terms PSTPIP1, PAID, PAPA syndrome and PAMI syndrome. This information was collected and used to form comparisons between the current literature and our reported case. CONCLUSIONS: Our case contributes to the literature on PAMI syndrome whilst providing an example of a potentially unique clinical phenotype, giving insight into the pre-symptomatic phase of the condition. We highlight the importance of considering PAMI syndrome in the differential for early onset unexplained inflammation. In addition, we explore the possibility that perinatal neurovascular events could be an early feature of PAMI syndrome.


Asunto(s)
Acné Vulgar , Artritis Infecciosa , Piodermia Gangrenosa , Acné Vulgar/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Artritis Infecciosa/genética , Sistema Nervioso Central , Proteínas del Citoesqueleto/genética , Femenino , Humanos , Mutación , Fenotipo , Piodermia Gangrenosa/genética , Síndrome
8.
Brain Commun ; 3(1): fcab002, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33634263

RESUMEN

A subset of individuals diagnosed with cerebral palsy will have an underlying genetic diagnosis. Previously, a missense variant in GAD1 was described as a candidate mutation in a single family diagnosed with autosomal recessive spastic cerebral palsy-1 (CPSQ1; OMIM 603513). Following the ascertainment of a further branch of the CPSQ1 kindred, we found that the previously reported GAD1 variant did not segregate with the neurological disease phenotype in the recently ascertained branch of the kindred. Following genetic linkage studies to map autozygous regions and whole-exome sequencing, a missense variant (c.527 T > C; p. Leu176Pro, rs773333490) in the HPDL gene was detected and found to segregate with disease status in both branches of the kindred. HPDL encodes a 371-amino acid protein (4-Hydroxyphenylpyruvate Dioxygenase Like) that localizes to mitochondria but whose function is uncertain. Recently, biallelic loss of function variants and missense substitution-causing variants in HPDL were reported to cause a childhood onset progressive spastic movement disorder with a variable presentation. These findings suggest that HPDL-related neurological disease may mimic spastic cerebral palsy and that GAD1 should not be included in diagnostic gene panels for inherited cerebral palsy.

9.
Cell Death Differ ; 27(5): 1457-1474, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32231246

RESUMEN

Methionine-1 (M1)-linked polyubiquitin chains conjugated by the linear ubiquitin chain assembly complex (LUBAC) control NF-κB activation, immune homoeostasis, and prevents tumour necrosis factor (TNF)-induced cell death. The deubiquitinase OTULIN negatively regulates M1-linked polyubiquitin signalling by removing the chains conjugated by LUBAC, and OTULIN deficiency causes OTULIN-related autoinflammatory syndrome (ORAS) in humans. However, the cellular pathways and physiological functions controlled by OTULIN remain poorly understood. Here, we show that OTULIN prevents development of liver disease in mice and humans. In an ORAS patient, OTULIN deficiency caused spontaneous and progressive steatotic liver disease at 10-13 months of age. Similarly, liver-specific deletion of OTULIN in mice leads to neonatally onset steatosis and hepatitis, akin to the ORAS patient. OTULIN deficiency triggers metabolic alterations, apoptosis, and inflammation in the liver. In mice, steatosis progresses to steatohepatitis, fibrosis and pre-malignant tumour formation by 8 weeks of age, and by the age of 7-12 months the phenotype has advanced to malignant hepatocellular carcinoma. Surprisingly, the pathology in OTULIN-deficient livers is independent of TNFR1 signalling. Instead, we find that steatohepatitis in OTULIN-deficient livers is associated with aberrant mTOR activation, and inhibition of mTOR by rapamycin administration significantly reduces the liver pathology. Collectively, our results reveal that OTULIN is critical for maintaining liver homoeostasis and suggest that M1-linked polyubiquitin chains may play a role in regulation of mTOR signalling and metabolism in the liver.


Asunto(s)
Endopeptidasas/metabolismo , Inflamación/complicaciones , Cirrosis Hepática/complicaciones , Neoplasias Hepáticas/complicaciones , Hígado/patología , Animales , Animales Recién Nacidos , Carcinogénesis/metabolismo , Carcinogénesis/patología , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Muerte Celular , Proliferación Celular , Endopeptidasas/deficiencia , Hígado Graso/complicaciones , Femenino , Eliminación de Gen , Hematopoyesis , Humanos , Inflamación/patología , Hígado/efectos de los fármacos , Cirrosis Hepática/patología , Neoplasias Hepáticas/patología , Masculino , Ratones , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Transducción de Señal , Sirolimus , Serina-Treonina Quinasas TOR/metabolismo
10.
Am J Med Genet A ; 182(4): 713-720, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31926053

RESUMEN

Developmental and Epileptic encephalopathies (DEE) describe heterogeneous epilepsy syndromes, characterized by early-onset, refractory seizures and developmental delay (DD). Several DEE associated genes have been reported. With increased access to whole exome sequencing (WES), new candidate genes are being identified although there are fewer large cohort papers describing the clinical phenotype in such patients. We describe 6 unreported individuals and provide updated information on an additional previously reported individual with heterozygous de novo missense variants in YWHAG. We describe a syndromal phenotype, report 5 novel, and a recurrent p.Arg132Cys YWHAG variant and compare developmental trajectory and treatment strategies in this cohort. We provide further evidence of causality in YWHAG variants. WES was performed in five patients via Deciphering Developmental Disorders Study and the remaining two were identified via Genematcher and AnnEX databases. De novo variants identified from exome data were validated using Sanger sequencing. Seven out of seven patients in the cohort have de novo, heterozygous missense variants in YWHAG including 2/7 patients with a recurrent c.394C > T, p.Arg132Cys variant; 1/7 has a second, pathogenic variant in STAG1. Characteristic features included: early-onset seizures, predominantly generalized tonic-clonic and absence type (7/7) with good response to standard anti-epileptic medications; moderate DD; Intellectual Disability (ID) (5/7) and Autism Spectrum Disorder (3/7). De novo YWHAG missense variants cause EE, characterized by early-onset epilepsy, ID and DD, supporting the hypothesis that YWHAG loss-of-function causes a neurological phenotype. Although the exact mechanism of disease resulting from alterations in YWHAG is not fully known, it is possible that haploinsufficiency of YWHAG in developing cerebral cortex may lead to abnormal neuronal migration resulting in DEE.


Asunto(s)
Proteínas 14-3-3/genética , Síndromes Epilépticos/etiología , Estudios de Asociación Genética , Heterocigoto , Mutación Missense , Trastornos del Neurodesarrollo/etiología , Adolescente , Niño , Preescolar , Síndromes Epilépticos/patología , Femenino , Humanos , Masculino , Trastornos del Neurodesarrollo/patología
11.
Am J Hum Genet ; 104(4): 596-610, 2019 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-30879640

RESUMEN

Mutations in several genes encoding components of the SWI/SNF chromatin remodeling complex cause neurodevelopmental disorders (NDDs). Here, we report on five individuals with mutations in SMARCD1; the individuals present with developmental delay, intellectual disability, hypotonia, feeding difficulties, and small hands and feet. Trio exome sequencing proved the mutations to be de novo in four of the five individuals. Mutations in other SWI/SNF components cause Coffin-Siris syndrome, Nicolaides-Baraitser syndrome, or other syndromic and non-syndromic NDDs. Although the individuals presented here have dysmorphisms and some clinical overlap with these syndromes, they lack their typical facial dysmorphisms. To gain insight into the function of SMARCD1 in neurons, we investigated the Drosophila ortholog Bap60 in postmitotic memory-forming neurons of the adult Drosophila mushroom body (MB). Targeted knockdown of Bap60 in the MB of adult flies causes defects in long-term memory. Mushroom-body-specific transcriptome analysis revealed that Bap60 is required for context-dependent expression of genes involved in neuron function and development in juvenile flies when synaptic connections are actively being formed in response to experience. Taken together, we identify an NDD caused by SMARCD1 mutations and establish a role for the SMARCD1 ortholog Bap60 in the regulation of neurodevelopmental genes during a critical time window of juvenile adult brain development when neuronal circuits that are required for learning and memory are formed.


Asunto(s)
Proteínas Cromosómicas no Histona/genética , Memoria , Trastornos del Neurodesarrollo/genética , Neuronas/metabolismo , Animales , Niño , Preescolar , Discapacidades del Desarrollo/genética , Modelos Animales de Enfermedad , Proteínas de Drosophila/genética , Drosophila melanogaster , Femenino , Regulación de la Expresión Génica , Humanos , Discapacidad Intelectual/genética , Aprendizaje , Masculino , Mitosis , Hipotonía Muscular/genética , Cuerpos Pedunculados , Mutación , Síndrome , Factores de Transcripción/genética
12.
Hum Mutat ; 39(9): 1246-1261, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29924900

RESUMEN

Adams-Oliver syndrome (AOS) is a rare developmental disorder, characterized by scalp aplasia cutis congenita (ACC) and transverse terminal limb defects (TTLD). Autosomal dominant forms of AOS are linked to mutations in ARHGAP31, DLL4, NOTCH1 or RBPJ, while DOCK6 and EOGT underlie autosomal recessive inheritance. Data on the frequency and distribution of mutations in large cohorts are currently limited. The purpose of this study was therefore to comprehensively examine the genetic architecture of AOS in an extensive cohort. Molecular diagnostic screening of 194 AOS/ACC/TTLD probands/families was conducted using next-generation and/or capillary sequencing analyses. In total, we identified 63 (likely) pathogenic mutations, comprising 56 distinct and 22 novel mutations, providing a molecular diagnosis in 30% of patients. Taken together with previous reports, these findings bring the total number of reported disease variants to 63, with a diagnostic yield of 36% in familial cases. NOTCH1 is the major contributor, underlying 10% of AOS/ACC/TTLD cases, with DLL4 (6%), DOCK6 (6%), ARHGAP31 (3%), EOGT (3%), and RBPJ (2%) representing additional causality in this cohort. We confirm the relevance of genetic screening across the AOS/ACC/TTLD spectrum, highlighting preliminary but important genotype-phenotype correlations. This cohort offers potential for further gene identification to address missing heritability.


Asunto(s)
Displasia Ectodérmica/genética , Deformidades Congénitas de las Extremidades/genética , Dermatosis del Cuero Cabelludo/congénito , Proteínas de Unión al GTP rho/genética , Displasia Ectodérmica/fisiopatología , Extremidades/fisiopatología , Femenino , Estudios de Asociación Genética , Humanos , Deformidades Congénitas de las Extremidades/fisiopatología , Masculino , Mutación , Linaje , Receptores Notch/genética , Cuero Cabelludo/fisiopatología , Dermatosis del Cuero Cabelludo/genética , Dermatosis del Cuero Cabelludo/fisiopatología
13.
Hum Mutat ; 39(6): 822-826, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29573052

RESUMEN

Defective glycosylphosphatidylinositol (GPI)-anchor biogenesis can cause a spectrum of predominantly neurological problems. For eight genes critical to this biological process, disease associations are not yet reported. Scanning exomes from 7,833 parent-child trios and 1,792 singletons from the DDD study for biallelic variants in this gene-set uncovered a rare PIGH variant in a boy with epilepsy, microcephaly, and behavioral difficulties. Although only 2/2 reads harbored this c.1A > T transversion, the presence of ∼25 Mb autozygosity at this locus implied homozygosity, which was confirmed using Sanger sequencing. A similarly-affected sister was also homozygous. FACS analysis of PIGH-deficient CHO cells indicated that cDNAs with c.1A > T could not efficiently restore expression of GPI-APs. Truncation of PIGH protein was consistent with the utilization of an in-frame start-site at codon 63. In summary, we describe siblings harboring a homozygous c.1A > T variant resulting in defective GPI-anchor biogenesis and highlight the importance of exploring low-coverage variants within autozygous regions.


Asunto(s)
Discapacidades del Desarrollo/genética , Epilepsia/genética , Proteínas de la Membrana/genética , Microcefalia/genética , Adolescente , Animales , Niño , Preescolar , Codón Iniciador/genética , Cricetinae , Discapacidades del Desarrollo/fisiopatología , Epilepsia/fisiopatología , Exoma/genética , Femenino , Glicosilfosfatidilinositoles/genética , Humanos , Masculino , Microcefalia/fisiopatología , Mutación , Linaje
14.
Elife ; 62017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28414270

RESUMEN

MFN2 encodes mitofusin 2, a membrane-bound mediator of mitochondrial membrane fusion and inter-organelle communication. MFN2 mutations cause axonal neuropathy, with associated lipodystrophy only occasionally noted, however homozygosity for the p.Arg707Trp mutation was recently associated with upper body adipose overgrowth. We describe similar massive adipose overgrowth with suppressed leptin expression in four further patients with biallelic MFN2 mutations and at least one p.Arg707Trp allele. Overgrown tissue was composed of normal-sized, UCP1-negative unilocular adipocytes, with mitochondrial network fragmentation, disorganised cristae, and increased autophagosomes. There was strong transcriptional evidence of mitochondrial stress signalling, increased protein synthesis, and suppression of signatures of cell death in affected tissue, whereas mitochondrial morphology and gene expression were normal in skin fibroblasts. These findings suggest that specific MFN2 mutations cause tissue-selective mitochondrial dysfunction with increased adipocyte proliferation and survival, confirm a novel form of excess adiposity with paradoxical suppression of leptin expression, and suggest potential targeted therapies.


Asunto(s)
Tejido Adiposo/fisiopatología , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Hiperplasia/fisiopatología , Leptina/biosíntesis , Mitocondrias/metabolismo , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Mutación , Cuerpo Humano , Humanos
15.
J Clin Endocrinol Metab ; 102(6): 2019-2028, 2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28323974

RESUMEN

Context: Recessive mutations in TMEM38B cause type XIV osteogenesis imperfecta (OI) by dysregulating intracellular calcium flux. Objectives: Clinical and bone material phenotype description and osteoblast differentiation studies. Design and Setting: Natural history study in pediatric research centers. Patients: Eight patients with type XIV OI. Main Outcome Measures: Clinical examinations included bone mineral density, radiographs, echocardiography, and muscle biopsy. Bone biopsy samples (n = 3) were analyzed using histomorphometry, quantitative backscattered electron microscopy, and Raman microspectroscopy. Cellular differentiation studies were performed on proband and control osteoblasts and normal murine osteoclasts. Results: Type XIV OI clinical phenotype ranges from asymptomatic to severe. Previously unreported features include vertebral fractures, periosteal cloaking, coxa vara, and extraskeletal features (muscular hypotonia, cardiac abnormalities). Proband lumbar spine bone density z score was reduced [median -3.3 (range -4.77 to +0.1; n = 7)] and increased by +1.7 (1.17 to 3.0; n = 3) following bisphosphonate therapy. TMEM38B mutant bone has reduced trabecular bone volume, osteoblast, and particularly osteoclast numbers, with >80% reduction in bone resorption. Bone matrix mineralization is normal and nanoporosity low. We demonstrate a complex osteoblast differentiation defect with decreased expression of early markers and increased expression of late and mineralization-related markers. Predominance of trimeric intracellular cation channel type B over type A expression in murine osteoclasts supports an intrinsic osteoclast defect underlying low bone turnover. Conclusions: OI type XIV has a bone histology, matrix mineralization, and osteoblast differentiation pattern that is distinct from OI with collagen defects. Probands are responsive to bisphosphonates and some show muscular and cardiovascular features possibly related to intracellular calcium flux abnormalities.


Asunto(s)
Coxa Vara/fisiopatología , Canales Iónicos/genética , Osteoblastos/fisiología , Osteoclastos/fisiología , Osteogénesis Imperfecta/fisiopatología , Fracturas de la Columna Vertebral/fisiopatología , Adolescente , Adulto , Animales , Densidad Ósea , Calcio/metabolismo , Hueso Esponjoso/diagnóstico por imagen , Hueso Esponjoso/patología , Estudios de Casos y Controles , Recuento de Células , Diferenciación Celular , Niño , Preescolar , Coxa Vara/etiología , Ecocardiografía , Femenino , Perfilación de la Expresión Génica , Genotipo , Cardiopatías/diagnóstico por imagen , Cardiopatías/etiología , Cardiopatías/fisiopatología , Heterocigoto , Humanos , Lactante , Recién Nacido , Canales Iónicos/metabolismo , Vértebras Lumbares/diagnóstico por imagen , Masculino , Ratones , Microscopía Electrónica , Hipotonía Muscular/etiología , Hipotonía Muscular/fisiopatología , Mutación , Tamaño de los Órganos , Osteoblastos/citología , Osteoclastos/citología , Osteogénesis Imperfecta/complicaciones , Osteogénesis Imperfecta/diagnóstico por imagen , Osteogénesis Imperfecta/genética , Fenotipo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Índice de Severidad de la Enfermedad , Espectrometría Raman , Fracturas de la Columna Vertebral/etiología , Adulto Joven
16.
Cell ; 166(5): 1215-1230.e20, 2016 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-27523608

RESUMEN

Methionine-1 (M1)-linked ubiquitin chains regulate the activity of NF-κB, immune homeostasis, and responses to infection. The importance of negative regulators of M1-linked chains in vivo remains poorly understood. Here, we show that the M1-specific deubiquitinase OTULIN is essential for preventing TNF-associated systemic inflammation in humans and mice. A homozygous hypomorphic mutation in human OTULIN causes a potentially fatal autoinflammatory condition termed OTULIN-related autoinflammatory syndrome (ORAS). Four independent OTULIN mouse models reveal that OTULIN deficiency in immune cells results in cell-type-specific effects, ranging from over-production of inflammatory cytokines and autoimmunity due to accumulation of M1-linked polyubiquitin and spontaneous NF-κB activation in myeloid cells to downregulation of M1-polyubiquitin signaling by degradation of LUBAC in B and T cells. Remarkably, treatment with anti-TNF neutralizing antibodies ameliorates inflammation in ORAS patients and rescues mouse phenotypes. Hence, OTULIN is critical for restraining life-threatening spontaneous inflammation and maintaining immune homeostasis.


Asunto(s)
Enfermedades Autoinmunes/genética , Autoinmunidad/genética , Enzimas Desubicuitinizantes/metabolismo , Endopeptidasas/metabolismo , Inflamación/genética , Animales , Anticuerpos Neutralizantes/uso terapéutico , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/terapia , Linfocitos B/inmunología , Citocinas/metabolismo , Enzimas Desubicuitinizantes/genética , Modelos Animales de Enfermedad , Endopeptidasas/genética , Mutación de Línea Germinal , Humanos , Inflamación/inmunología , Inflamación/terapia , Infliximab/uso terapéutico , Metionina/metabolismo , Ratones , Ratones Mutantes , Células Mieloides/inmunología , Poliubiquitina/metabolismo , Eliminación de Secuencia , Síndrome , Linfocitos T/inmunología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
17.
Clin Dysmorphol ; 24(1): 13-6, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25325185

RESUMEN

Branchio-oculo-facial syndrome (BOFS) is a rare autosomal dominant condition with variable expressivity, caused by mutations in the TFAP2A gene. We report a three generational family with four affected individuals. The consultand has typical features of BOFS including infra-auricular skin nodules, coloboma, lacrimal duct atresia, cleft lip, conductive hearing loss and typical facial appearance. She also exhibited a rare feature of preaxial polydactyly. Her brother had a lethal phenotype with multiorgan failure. We also report a novel variant in TFAP2A gene. This family highlights the variable severity of BOFS and, therefore, the importance of informed genetic counselling in families with BOFS.


Asunto(s)
Síndrome Branquio Oto Renal/patología , Muerte Perinatal , Adolescente , Niño , Preescolar , Familia , Resultado Fatal , Femenino , Humanos , Recién Nacido , Masculino , Linaje , Fenotipo , Adulto Joven
18.
Eur J Hum Genet ; 23(2): 224-8, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24736733

RESUMEN

Shprintzen-Goldberg syndrome (SGS) is a rare, systemic connective tissue disorder characterized by craniofacial, skeletal, and cardiovascular manifestations that show a significant overlap with the features observed in the Marfan (MFS) and Loeys-Dietz syndrome (LDS). A distinguishing observation in SGS patients is the presence of intellectual disability, although not all patients in this series present this finding. Recently, SGS was shown to be due to mutations in the SKI gene, encoding the oncoprotein SKI, a repressor of TGFß activity. Here, we report eight recurrent and three novel SKI mutations in eleven SGS patients. All were heterozygous missense mutations located in the R-SMAD binding domain, except for one novel in-frame deletion affecting the DHD domain. Adding our new findings to the existing data clearly reveals a mutational hotspot, with 73% (24 out of 33) of the hitherto described unrelated patients having mutations in a stretch of five SKI residues (from p.(Ser31) to p.(Pro35)). This implicates that the initial molecular testing could be focused on mutation analysis of the first half of exon 1 of SKI. As the majority of the known mutations are located in the R-SMAD binding domain of SKI, our study further emphasizes the importance of TGFß signaling in the pathogenesis of SGS.


Asunto(s)
Aracnodactilia/genética , Craneosinostosis/genética , Proteínas de Unión al ADN/genética , Síndrome de Marfan/genética , Mutación Missense , Proteínas Proto-Oncogénicas/genética , Adolescente , Adulto , Aracnodactilia/diagnóstico , Sitios de Unión , Niño , Preescolar , Craneosinostosis/diagnóstico , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Exones , Femenino , Humanos , Masculino , Síndrome de Marfan/diagnóstico , Persona de Mediana Edad , Unión Proteica , Proteínas Proto-Oncogénicas/química , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Smad/metabolismo
19.
Am J Med Genet A ; 164A(7): 1695-701, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24715413

RESUMEN

Axenfeld-Rieger syndrome (ARS) is an autosomal dominant disorder with variable expressivity. It is characterized by dysgenesis of the anterior segment of the eye together with dental, cardiac, and umbilical anomalies. There is a high incidence of secondary high tension glaucoma. It is a genetically heterogeneous condition due to deletion or mutations of FOXC1 (6p25) or PITX2 (4q25). We report on four unrelated patients with overlapping microdeletions encompassing PITX2 at 4q25. We compare the genotypes and phenotypes of these newly described ARS patients and discuss the involvement of contiguous genes. Patients 1, 2, and 3 had mild learning difficulties, not typically seen in patients with ARS. We implicate the adjacent neuronally expressed genes; NEUROG2, UGT8, NDST3, and PRSS12 as potentially causal. Our findings support the use of microarray analysis in ARS patients for full prognostic information in infants presenting with ARS-like phenotypes.


Asunto(s)
Segmento Anterior del Ojo/anomalías , Deleción Cromosómica , Cromosomas Humanos Par 4 , Anomalías del Ojo/diagnóstico , Anomalías del Ojo/genética , Estudios de Asociación Genética , Adulto , Niño , Preescolar , Bandeo Cromosómico , Hibridación Genómica Comparativa , Enfermedades Hereditarias del Ojo , Facies , Femenino , Humanos , Hibridación Fluorescente in Situ , Masculino , Fenotipo
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