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1.
J Clin Invest ; 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33465056

RESUMO

Leber's hereditary optic neuropathy (LHON) is the most frequent mitochondrial disease and was the first to be genetically defined by a point mutation in the mitochondrial DNA (mtDNA). A molecular diagnosis is reached in up to 95%, the vast majority of which are accounted for by three mutations within mitochondrial complex I (CI) subunit encoding genes in the mtDNA (mtLHON). Here, we resolve the enigma of LHON in the absence of pathogenic mtDNA mutations. We describe biallelic mutations in a nuclear encoded gene, DNAJC30, in 33 unsolved patients from 29 families and establish an autosomal recessive mode of inheritance for LHON (arLHON), which to date has been a prime example of a maternally inherited disorder. Remarkably, all hallmarks of mtLHON are recapitulated, including incomplete penetrance, male predominance, and significant idebenone responsivity. Moreover, by tracking protein turnover in patient-derived cell lines and a DNAJC30-knock-out cellular model, we measure reduced turnover of specific CI N-module subunits and a resultant impairment of CI function. This demonstrates DNAJC30 is to be a chaperone protein needed for the efficient exchange of CI subunits exposed to reactive oxygen species and integral to a mitochondrial CI repair mechanism, thereby providing the first example of a disease resulting from impaired exchange of assembled respiratory chain subunits.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33448213

RESUMO

A new syndrome of diabetes, short stature, microcephaly and intellectual disability has been described in association with mutations in the tRNA methyltransferase 10 homologue A (TRMT10A) gene. We report a patient who presented with fasting hyperglycemia, a raised HbA1C and positive islet cell autoantibodies. Additional clinical features included intellectual disability, hypoplastic kidneys and short stature. In view of syndromic features alongside diabetes, genetic evaluation was carried out revealing a homozygous mutation in the TRMT10A gene (c.616G>A, p.G206R). The case highlights the importance of genetic evaluation of patients with diabetes with atypical features that can further progress our understanding of the pathophysiology of the rarer subtypes of diabetes.

3.
J Exp Med ; 218(3)2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33231617

RESUMO

The T cell receptor (TCR) signaling pathway is an ensemble of numerous proteins that are crucial for an adequate immune response. Disruption of any protein involved in this pathway leads to severe immunodeficiency and unfavorable clinical outcomes. Here, we describe an infant with severe immunodeficiency who was found to have novel biallelic mutations in SLP76. SLP76 is a key protein involved in TCR signaling and in other hematopoietic pathways. Previous studies of this protein were performed using Jurkat-derived human leukemic T cell lines and SLP76-deficient mice. Our current study links this gene, for the first time, to a human immunodeficiency characterized by early-onset life-threatening infections, combined T and B cell immunodeficiency, severe neutrophil defects, and impaired platelet aggregation. Hereby, we characterized aspects of the patient's immune phenotype, modeled them with an SLP76-deficient Jurkat-derived T cell line, and rescued some consequences using ectopic expression of wild-type SLP76. Understanding human diseases due to SLP76 deficiency is helpful in explaining the mixed T cell and neutrophil defects, providing a guide for exploring human SLP76 biology.

4.
Am J Hum Genet ; 108(1): 115-133, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33308444

RESUMO

Signal peptide-CUB-EGF domain-containing protein 3 (SCUBE3) is a member of a small family of multifunctional cell surface-anchored glycoproteins functioning as co-receptors for a variety of growth factors. Here we report that bi-allelic inactivating variants in SCUBE3 have pleiotropic consequences on development and cause a previously unrecognized syndromic disorder. Eighteen affected individuals from nine unrelated families showed a consistent phenotype characterized by reduced growth, skeletal features, distinctive craniofacial appearance, and dental anomalies. In vitro functional validation studies demonstrated a variable impact of disease-causing variants on transcript processing, protein secretion and function, and their dysregulating effect on bone morphogenetic protein (BMP) signaling. We show that SCUBE3 acts as a BMP2/BMP4 co-receptor, recruits the BMP receptor complexes into raft microdomains, and positively modulates signaling possibly by augmenting the specific interactions between BMPs and BMP type I receptors. Scube3-/- mice showed craniofacial and dental defects, reduced body size, and defective endochondral bone growth due to impaired BMP-mediated chondrogenesis and osteogenesis, recapitulating the human disorder. Our findings identify a human disease caused by defective function of a member of the SCUBE family, and link SCUBE3 to processes controlling growth, morphogenesis, and bone and teeth development through modulation of BMP signaling.

5.
Eur J Med Genet ; 64(2): 104124, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33359164

RESUMO

The combination of congenital heart defects and vertebral anomalies with or without additional abnormalities has been reported in many genetic disorders. We describe a family in which four consecutive pregnancies were characterized by the combination of fetal congenital heart malformations and vertebral anomalies. In addition, preaxial polydactyly was detected in one of the fetuses. Reanalysis of the non-diagnostic clinical exome data revealed compound heterozygous variants c.350del, p.(Gly117AlafsTer90) and c.757G > T, p.(Asp253Tyr) in ETV2 which have previously not been known to be associated with a phenotype in humans. In mice, Etv2 encodes an obligatory transcription factor involved in the generation of hematopoietic and endothelial cells. Its homozygous disruption results in embryonic lethality due to severe blood and vessel defects. The Etv2 promoter may be bound by Nkx2-5, a key transcription factor in heart development. Pathogenic variants in the NKx2-5 homolog in humans (NKX2-5) are related to congenital heart defects. The identification of additional fetuses or live-born individuals with biallelic pathogenic variants in ETV2 will shed further light on this presumably novel gene-phenotype association and on the full phenotypic spectrum.

6.
Front Immunol ; 11: 1775, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33013830

RESUMO

Background: More than 50 different monogenic disorders have been identified as directly causing inflammatory bowel diseases, typically manifesting in the first years of life. We present the clinical course and immunological work-up of an adult patient who presented in adolescent years with an atypical gastrointestinal phenotype and was diagnosed more than two decades later with a monogenic disorder with important therapeutic implications. Methods: Whole exome sequencing was performed in a 37-years-old patient with a history of diarrhea since adolescence. Sanger sequencing was used to validate the suspected variant. Mass cytometry (CyTOF) and flow cytometry were conducted on peripheral blood mononuclear cells for deep immunophenotyping. Next-generation sequencing of the TCRB and IgH was performed for global immune repertoire analysis of circulating lymphocytes. Results: We identified a novel deleterious c.1455C>A (p.Y485X) mutation in LRBA. CyTOF studies demonstrated significant changes in immune landscape in the LRBA-deficient patient, including an increase in myeloid derived suppressor cells and double-negative T cells, decreased B cells, low ratio of naïve:memory T cells, and reduced capacity of T cells to secrete various cytokines following stimulation, including tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). In addition, this patient exhibited low frequency of regulatory T cells, with a reduction in their CTLA4 expression and interleukin (IL)-10 secretion. Finally, we show marked oligoclonal expansion of specific B- and T-cell clones in the peripheral blood of the LRBA-deficient patient. Conclusions: LRBA deficiency is characterized by marked immunological changes in innate and adaptive immune cells. This case highlights the importance of advanced genetic studies in patients with a unique phenotype, regardless of their age at presentation.

7.
Mol Genet Metab Rep ; 25: 100631, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32904102

RESUMO

Introduction: Peroxisomal D-bifunctional protein (DBP) deficiency is an autosomal recessive disorder historically described as a Zellweger-like syndrome comprising neonatal seizures, retinopathy, hearing loss, dysmorphic features, and other complications. The HSD17B4 gene encodes DBP which is essential for oxidation of peroxisomal substrates. We describe 4 patients - 2 unrelated female girls and 2 monozygotic twin sisters - with DBP deficiency and phenotypic diversity. Patient reports: Patient 1 presented neonatally with hypotonia and seizures, and later on developed global developmental delay and regression, sensorineural hearing loss, nystagmus and cortical blindness. The brain MRI demonstrated bilateral peri-sylvian polymicrogyria. Whole exome sequencing revealed 2 mutations in the HSD17B4 gene (c.752G>A, p.(Arg251Gln); c.868 + 1delG).Patient 2 presented with hypotonia, motor delay, and sensorineural hearing loss in infancy, considerable developmental regression during her fourth year, nystagmus, and peripheral neuropathy. Brain MRI demonstrated cerebellar atrophy and abnormal basal ganglia and white matter signal, which appeared after the age of two years. Whole exome sequencing revealed 2 mutations in the HSD17B4 gene (c.14 T>G, p.(Leu5Arg); c.752G>A, p.(Arg251Gln)).Patients 3 and 4, two female monozygotic twins, presented with hypotonia, developmental delay, and macrocephaly from birth, and later on also sensorineural hearing loss, infantile spasms and hypsarrhythmia, and adrenal insufficiency. Brain MRI demonstrated delayed myelination, and an assay of peroxisomal beta oxidation suggested DBP deficiency. Sequencing of the HSD17B4 gene revealed the same 2 mutations as in patient 1. Discussion: We describe 4 patients with variable and diverse clinical picture of DBP deficiency and particularly emphasize the clinical, biochemical, and neuroimaging characteristics. Interestingly, the clinical phenotype varied even between patients with the exact two mutations in the HSD17B4 gene. In addition, in two of the three patients in whom levels of VLCFA including phytanic acid were measured, the levels were within normal limits. This is expanding further the clinical spectrum of this disorder, which should be considered in the differential diagnosis of every patient with hypotonia and developmental delay especially if accompanied by polymicrogyria, seizures, sensorineural hearing loss, or adrenal insufficiency regardless of their VLCFA profile.

8.
Genes Immun ; 21(5): 326-334, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32921793

RESUMO

Mutations in the common gamma chain of the interleukin 2 receptor (IL2RG) or the associated downstream signaling enzyme Janus kinase 3 (JAK3) genes are typically characterized by a T cell-negative, B cell-positive, natural killer (NK) cell-negative (T-B+NK-) severe combined immunodeficiency (SCID) immune phenotype. We report clinical course, immunological, genetic and proteomic work-up of two patients with different novel mutations in the IL-2-JAK3 pathway with a rare atypical presentation of T-B+NK- SCID. Lymphocyte subpopulation revealed significant T cells lymphopenia, normal B cells, and NK cells counts (T-B+NK+SCID). Despite the presence of B cells, IgG levels were low and IgA and IgM levels were undetectable. T-cell proliferation in response to mitogens in patient 1 was very low and T-cell receptor V-beta chain repertoire in patient 2 was polyclonal. Whole-exome sequencing revealed novel mutations in both patients (patient 1-c.923delC frame-shift mutation in the IL2RG gene, patient 2-c.G172A a homozygous missense mutation in the JAK3 gene). Bioinformatic analysis of the JAK3 mutation indicated deleterious effect and 3D protein modeling located the mutation to a surface exposed alpha-helix structure. Our findings help to link between genotype and phenotype, which is a key factor for the diagnosis and treatment of SCID patients.

9.
Pediatr Blood Cancer ; 67(6): e28237, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32277798

RESUMO

BACKGROUND: The SRP54 (signal recognition protein 54) is a conserved component of the ribonucleoprotein complex that mediates cotranslational targeting and translocation of proteins to the endoplasmic reticulum. In 2017, mutations in the gene have been described as a cause of congenital neutropenia with or without pancreatic insufficiency, and since then, only limited cases were added to the literature. METHODS: Two patients with neutropenia underwent hematological, immunological, and genetic work-up, including lymphocyte phenotyping, immunoglobulins, and complement levels, antineutrophil and antinuclear antibodies, bone marrow FISH panel for myelodysplastic syndrome, whole-exome sequencing, and in silico proteomic analysis. RESULTS: Clinical findings in the two families revealed a wide spectrum of immunological and clinical manifestations, ranging from mild asymptomatic neutropenia during febrile illnesses to severe neutropenia and life-threatening infection requiring leg amputation. Immunological and hematological work-up showed isolated neutropenia with normal lymphocyte subpopulations, immunoglobulin and complement levels, and negative autoimmune tests. Bone marrow aspirations showed variability ranging from normal myelopoiesis to myeloid maturation arrest at the promyelocytic stage, with normal FISH panel for myelodysplastic syndrome. Genetic analysis identified a novel, de novo, in-frame deletion in the SRP54 gene, c.342-344delAAC, p.T115del. In silico proteomic analysis suggested impaired SRP54 protein function due to reduced GTP activity and stability. CONCLUSIONS: We describe congenital neutropenia with variable clinical presentation in novel mutation of the SRP54 gene.


Assuntos
Mutação , Neutropenia/congênito , Neutropenia/patologia , Partícula de Reconhecimento de Sinal/genética , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Neutropenia/genética , Neutropenia/metabolismo , Linhagem , Prognóstico , Proteômica , Sequenciamento Completo do Exoma
10.
Clin Immunol ; 214: 108376, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32135276

RESUMO

Primary immunodeficiencies (PIDs) are a heterogeneous group of monogenic inborn errors of immunity. The genetic causes of these diseases can be identified using whole exome sequencing (WES). Here, DNA samples from 106 patients with a clinical suspicion of PID were subjected to WES in order to test the diagnostic yield of this test in a highly consanguineous community. A likely genetic diagnosis was achieved in 70% of patients. Several factors were considered to possibly influence the diagnostic rate of WES among our cohort including early age, presence of consanguinity, family history suggestive of PID, the number of family members who underwent WES and the clinical phenotype of the patient. The highest diagnostic rate was in patients with combined immunodeficiency or with a syndrome. Notably, WES findings altered the clinical management in 39% (41/106) of patients in our cohort. Our findings support the use of WES as an important diagnostic tool in patients with suspected PID, especially in highly consanguineous communities.


Assuntos
Mutação , Doenças da Imunodeficiência Primária/diagnóstico , Sequenciamento Completo do Exoma , Adolescente , Adulto , Doenças Autoimunes/epidemiologia , Doenças Autoimunes/genética , Criança , Pré-Escolar , Tomada de Decisão Clínica , Consanguinidade , Gerenciamento Clínico , Feminino , Genótipo , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Recém-Nascido , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/genética , Israel/epidemiologia , Masculino , Doenças da Imunodeficiência Primária/epidemiologia , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/terapia , Adulto Jovem
11.
Artigo em Inglês | MEDLINE | ID: mdl-32144877

RESUMO

The genetic basis of congenital heart malformations associated with disruption of left-right (L-R) asymmetry is broad and heterogenous, with variants in over 25 genes implicated thus far. Of these, deleterious variants in the Growth/Differentiation Factor 1 (GDF1) gene have been shown to cause heterotaxy with varied complex heart malformations of left-right patterning, in 23 individuals reported to date, either in monoallelic or biallelic state. We report three unrelated individuals exhibiting right isomerism with congenital heart defects, each originating from a consanguineous kindred of Arab-Muslim descent. Using whole exome sequencing, a shared novel homozygous truncating c.608G > A (p.W203*) variant in the GDF1 gene was revealed as the molecular basis of their disease. Subsequently, targeted sequencing of this variant showed full segregation with the disease in these families, with a total of over 15 reportedly affected individuals, enabling genetic counseling, prenatal diagnosis, and planning of future pregnancies. Our findings further confirm the association of biallelic GDF1 variants, heterotaxy and congenital heart defects of left-right patterning, and expand the previously described phenotypic spectrum and mutational profile. Moreover, we suggest targeted screening for the p.W203* variant in relevant clinical circumstances.

12.
Am J Hum Genet ; 106(2): 246-255, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32004447

RESUMO

Ral (Ras-like) GTPases play an important role in the control of cell migration and have been implicated in Ras-mediated tumorigenicity. Recently, variants in RALA were also described as a cause of intellectual disability and developmental delay, indicating the relevance of this pathway to neuropediatric diseases. Here, we report the identification of bi-allelic variants in RALGAPA1 (encoding Ral GTPase activating protein catalytic alpha subunit 1) in four unrelated individuals with profound neurodevelopmental disability, muscular hypotonia, feeding abnormalities, recurrent fever episodes, and infantile spasms . Dysplasia of corpus callosum with focal thinning of the posterior part and characteristic facial features appeared to be unifying findings. RalGAPA1 was absent in the fibroblasts derived from two affected individuals suggesting a loss-of-function effect of the RALGAPA1 variants. Consequently, RalA activity was increased in these cell lines, which is in keeping with the idea that RalGAPA1 deficiency causes a constitutive activation of RalA. Additionally, levels of RalGAPB, a scaffolding subunit of the RalGAP complex, were dramatically reduced, indicating a dysfunctional RalGAP complex. Moreover, RalGAPA1 deficiency clearly increased cell-surface levels of lipid raft components in detached fibroblasts, which might indicate that anchorage-dependence of cell growth signaling is disturbed. Our findings indicate that the dysregulation of the RalA pathway has an important impact on neuronal function and brain development. In light of the partially overlapping phenotype between RALA- and RALGAPA1-associated diseases, it appears likely that dysregulation of the RalA signaling pathway leads to a distinct group of genetic syndromes that we suggest could be named RALopathies.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos/etiologia , Proteínas Ativadoras de GTPase/genética , Hipotonia Muscular/etiologia , Mutação , Proteínas do Tecido Nervoso/genética , Transtornos do Neurodesenvolvimento/etiologia , Espasmos Infantis/etiologia , Alelos , Movimento Celular , Proliferação de Células , Pré-Escolar , Família , Transtornos da Alimentação e da Ingestão de Alimentos/patologia , Feminino , Humanos , Lactente , Masculino , Hipotonia Muscular/patologia , Transtornos do Neurodesenvolvimento/patologia , Fenótipo , Espasmos Infantis/patologia
13.
Hum Mutat ; 41(2): 476-486, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31692205

RESUMO

We describe the underlying genetic cause of a novel Rett-like phenotype accompanied by areflexia in three methyl-CpG-binding protein 2-negative individuals from two unrelated families. Discovery analysis was performed using whole-exome sequencing followed by Sanger sequencing for validation and segregation. Functional studies using short-hairpin RNA for targeted gene knockdown were implemented by the transfection of mouse cultured primary hippocampal neurons and in vivo by in utero electroporation. All patients shared a common homozygous frameshift mutation (chr9:135073515, c.376dupT, p.(Ser126PhefsTer241)) in netrin-G2 (NTNG2, NM_032536.3) with predicted nonsense-mediated decay. The mutation fully segregated with the disease in both families. The knockdown of either NTNG2 or the related netrin-G family member NTNG1 resulted in severe neurodevelopmental defects of neuronal morphology and migration. While NTNG1 has previously been linked to a Rett syndrome (RTT)-like phenotype, this is the first description of a RTT-like phenotype caused by NTNG2 mutation. Netrin-G proteins have been shown to be required for proper axonal guidance during early brain development and involved in N-methyl- d-aspartate-mediated synaptic transmission. Our results demonstrating that knockdown of murine NTNG2 causes severe impairments of neuronal morphology and cortical migration are consistent with those of RTT animal models and the shared neurodevelopmental phenotypes between the individuals described here and typical RTT patients.

14.
Muscle Nerve ; 61(3): 395-400, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31837156

RESUMO

BACKGROUND: Adult-onset hereditary motor neuropathies are caused by mutations in multiple genes. Mutations within the vaccinia-related kinase 1 (VRK1) gene were associated with a wide spectrum of recessively inherited motor neuropathies, characterized by childhood to early adulthood age of onset and an occasionally non-lower motor neuron involvement. METHODS: We describe two patients with adult-onset (aged 48 and 40 years) length-dependent motor neuropathy from unrelated consanguineous families of Moroccan Jewish descent. One also demonstrated mild nocturnal respiratory difficulty and sensory symptoms. Whole-exome sequencing (WES) was performed. RESULTS: A homozygous mutation in VRK1 (c.1160G>A (p.Arg387His)), shared by both patients, was identified. This rare mutation segregated with the disease in the two families, and was absent in 120 controls of Jewish Moroccan origin. CONCLUSIONS: Our findings support VRK1 as a causative gene for adult-onset distal hereditary motor neuropathy, and indicate its relevance for evaluation of individuals with similar motor impairment.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Atrofia Muscular Espinal/genética , Proteínas Serina-Treonina Quinases/genética , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Linhagem
15.
Front Genet ; 10: 425, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428121

RESUMO

Prenatal ultrasound (US) abnormalities often pose a clinical dilemma and necessitate facilitated investigations in the search of diagnosis. The strategy of pursuing fetal whole-exome sequencing (WES) for pregnancies complicated by abnormal US findings is gaining attention, but the reported diagnostic yield is variable. In this study, we describe a tertiary center's experience with fetal WES from both terminated and ongoing pregnancies, and examine the clinical factors affecting the diagnostic rate. A total of 45 consecutive families of Jewish descent were included in the analysis, for which clinical fetal WES was performed under either single (fetus only), trio (fetus and parents) or quatro (two fetuses and parents) design. Except one, all families were non-consanguineous. In 41 of the 45 families, WES was sought following abnormal fetal US findings, and 18 of them had positive relevant family history (two or more fetuses with US abnormalities, or single fetus with US abnormalities and an affected parent). The overall diagnostic yield was 28.9% (13/45 families), and 31.7% among families with fetal US abnormalities (13/41). It was significantly higher in families with prenatal US abnormalities and relevant family history (10/18, 55.6%), compared to families with prenatal US abnormal findings and lack of such history (3/23, 13%) (p = 0.004). WES yield was relatively high (42.9-60%) among families with involvement of brain, renal or musculoskeletal US findings. Taken together, our results in a real-world setting of genetic counseling demonstrates that fetal WES is especially indicated in families with positive family history, as well as in fetuses with specific types of congenital malformation.

16.
Am J Med Genet A ; 179(10): 2112-2118, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31444901

RESUMO

Generalized arterial calcifications of infancy (GACI) is caused by mutations in ENPP1. Other ENPP1-related phenotypes include pseudoxanthoma elasticum, hypophosphatemic rickets, and Cole disease. We studied four children from two Bedouin consanguineous families who presented with severe clinical phenotype including thrombocytopenia, hypoglycemia, hepatic, and neurologic manifestations. Initial working diagnosis included congenital infection; however, patients remained without a definitive diagnosis despite extensive workup. Consequently, we investigated a potential genetic etiology. Whole exome sequencing (WES) was performed for affected children and their parents. Following the identification of a novel mutation in the ENPP1 gene, we characterized this novel multisystemic presentation and revised relevant imaging studies. Using WES, we identified a novel homozygous mutation (c.556G > C; p.Gly186Arg) in ENPP1 which affects a highly conserved protein domain (somatomedin B2). ENPP1-associated genetic diseases exhibit phenotypic heterogeneity depending on mutation type and location. Follow-up clinical characterization of these families allowed us to revise and detect new features of systemic calcifications, which established the diagnosis of GACI, expanding the phenotypic spectrum associated with ENPP1 mutations. Our findings demonstrate that this novel ENPP1 founder mutation can cause a fatal multisystemic phenotype, mimicking severe congenital infection. This also represents the first reported mutation affecting the SMB2 domain, associated with GACI.


Assuntos
Anormalidades Cardiovasculares/genética , Sistema Nervoso Central/anormalidades , Mutação/genética , Diester Fosfórico Hidrolases/genética , Pirofosfatases/genética , Trombocitopenia/genética , Calcificação Vascular/genética , Sequência de Bases , Anormalidades Cardiovasculares/complicações , Anormalidades Cardiovasculares/diagnóstico por imagem , Sistema Nervoso Central/diagnóstico por imagem , Evolução Fatal , Feminino , Predisposição Genética para Doença , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Linhagem , Fenótipo , Gravidez , Síndrome , Trombocitopenia/complicações , Calcificação Vascular/complicações , Calcificação Vascular/diagnóstico por imagem
17.
Front Immunol ; 10: 1672, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31379863

RESUMO

The alpha subunit of IL-7 receptor (IL7R7α) is critical for the differentiation of T cells, specifically for the development and maintenance of γδT cells. Mutations in IL7RA are associated with Severe Combined Immunodeficiency (SCID). Infants with IL7RA deficiency can be identified through newborn screening program. We aimed at defining the immunological and genetic parameters that are directly affected by the IL7RA mutation on the immune system of five unrelated patients which were identified by our newborn screening program for SCID. The patients were found to have a novel identical homozygote mutation in IL7RA (n.c.120 C>G; p.F40L). Both surface expression of IL7Rα and functionality of IL-7 signaling were impaired in patients compared to controls. Structural modeling demonstrated instability of the protein structure due to the mutation. Lastly the TRG immune repertoire of the patients showed reduced diversity, increased clonality and differential CDR3 characteristics. Interestingly, the patients displayed significant different clinical outcome with two displaying severe clinical picture of immunodeficiency and three had spontaneous recovery. Our data supports that the presented IL7RA mutation affects the IL-7 signaling and shaping of the TRG repertoire, reinforcing the role of IL7RA in the immune system, while non-genetic factors may exist that attribute to the ultimate clinical presentation and disease progression.


Assuntos
Subunidade alfa de Receptor de Interleucina-7/genética , Subunidade alfa de Receptor de Interleucina-7/imunologia , Mutação/genética , Mutação/imunologia , Feminino , Humanos , Sistema Imunitário/imunologia , Recém-Nascido , Masculino , Triagem Neonatal/métodos , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T
18.
Pediatr Rheumatol Online J ; 17(1): 52, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362757

RESUMO

BACKGROUND: Systemic lupus erythematosus (SLE) comprise a diverse range of clinical manifestations. To date, more than 30 single gene causes of lupus/lupus like syndromes in humans have been identified. In the clinical setting, identifying the underlying molecular diagnosis is challenging due to phenotypic and genetic heterogeneity. METHODS: We employed whole exome sequencing (WES) in patients presenting with childhood-onset lupus with severe and/or atypical presentations to identify cases that are explained by a single-gene (monogenic) cause. RESULTS: From January 2015 to June 2018 15 new cases of childhood-onset SLE were diagnosed in Edmond and Lily Safra Children's Hospital. By WES we identified causative mutations in four subjects in five different genes: C1QC, SLC7A7, MAN2B1, PTEN and STAT1. No molecular diagnoses were established on clinical grounds prior to genetic testing. CONCLUSIONS: We identified a significant fraction of monogenic SLE etiologies using WES and confirm the genetic locus heterogeneity in childhood-onset lupus. These results highlight the importance of establishing a genetic diagnosis for children with severe or atypical lupus by providing accurate and early etiology-based diagnoses and improving subsequent clinical management.


Assuntos
Lúpus Eritematoso Sistêmico/genética , Mutação/genética , Sequenciamento Completo do Exoma/métodos , Adolescente , Sistema y+L de Transporte de Aminoácidos/genética , Criança , Pré-Escolar , Complemento C1q/genética , Feminino , Mutação com Ganho de Função/genética , Predisposição Genética para Doença/genética , Humanos , Masculino , PTEN Fosfo-Hidrolase/genética , Fator de Transcrição STAT1/genética , alfa-Manosidase/genética
19.
Pediatr Dermatol ; 36(5): 732-734, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31215057

RESUMO

We describe a 4-week-old baby boy who presented with white firm cutaneous nodules and failure to thrive. He did not have dysmorphic features, and laboratory tests including serum calcium, phosphorous, thyroid function, and parathyroid hormone level were within normal ranges. Whole exome sequencing revealed an inactivating mutation in GNAS that was previously described as causing pseudohypoparathyroidism.


Assuntos
Doenças Ósseas Metabólicas/genética , Doenças Ósseas Metabólicas/patologia , Cromograninas/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Mutação/genética , Ossificação Heterotópica/genética , Ossificação Heterotópica/patologia , Dermatopatias Genéticas/genética , Dermatopatias Genéticas/patologia , Humanos , Recém-Nascido , Masculino
20.
J Clin Immunol ; 39(4): 401-413, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31037583

RESUMO

MALT1 (mucosa-associated lymphoid tissue lymphoma-translocation gene 1) is an intracellular signaling protein that activates NFκB and is crucial for both the adaptive and innate immune responses. Only 6 patients with immune deficiencies secondary to inherited mutations in the MALT1 gene have been described. PURPOSE: To provide clinical and immunological insights from 2 patients diagnosed with MALT1 immunodeficiency syndrome due to a novel MALT1 mutation. METHODS: Two cousins with suspected combined immunodeficiency underwent immunological and genetic work-up, including lymphocyte phenotyping, lymphocyte activation by mitogen stimulation, and next-generation sequencing (NGS) of T cell receptor gamma chain (TRG) repertoire. Whole exome sequencing was performed to identify the underlying genetic defect. RESULTS: Clinical findings included recurrent infections, failure to thrive, lymphadenopathy, dermatitis, and autoimmunity. Immune work-up revealed lymphocytosis, low to normal levels of immunoglobulins, absence of regulatory T cells, and low Th17 cells. A normal proliferative response was induced by phytohemagglutinin and IL-2 but was diminished with anti-CD3. TRG repertoire was diverse with a clonal expansion pattern. Genetic analysis identified a novel autosomal recessive homozygous c.1799T>A; p. I600N missense mutation in MALT1. MALT1 protein expression was markedly reduced, and in vitro IL-2 production and NFκB signaling pathway were significantly impaired. CONCLUSIONS: Two patients harboring a novel MALT1 mutation presented with signs of immune deficiency and dysregulation and were found to have an abnormal T cell receptor repertoire. These findings reinforce the link between MALT1 deficiency and combined immunodeficiency. Early diagnosis is crucial, and curative treatment by hematopoietic stem cell transplantation may be warranted.


Assuntos
Predisposição Genética para Doença , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/genética , Mutação , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Sequência de Aminoácidos , Biomarcadores , Consanguinidade , Citocinas/metabolismo , Feminino , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/metabolismo , Imunofenotipagem , Masculino , NF-kappa B/metabolismo , Linhagem , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
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