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1.
Eur J Med Genet ; 64(1): 104123, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33338668

RESUMO

PPP2R5D-related neurodevelopmental disorder (NDD) is a rare autosomal-dominant disease with developmental delay and mild to severe intellectual disability. So far, fewer than 30 affected individuals with mostly recurrent, de novo missense variants in PPP2R5D were reported. Recently, parkinsonism with an onset between 20 and 40 years was reported in four adult individuals with the same p.(Glu200Lys) variant in PPP2R5D. By trio exome sequencing we now identified the variant p.(Glu198Lys) in a 29 year old woman presenting with typical clinical manifestations of PPP2R5D-related neurodevelopmental disorder and additionally with motor decline and levodopa responsive, early-onset parkinsonism from her mid-twenties on. Accordingly, a clear reduction of dopamine transporter in the striatum on both sides was revealed by brain scintigraphy. Our findings further expand the molecular and clinical spectrum of PPP2R5D-related NDD and confirm the association with parkinsonism in early adulthood. This has marked implications for prognosis of PPP2R5D-related NDDs and for the therapeutic management of motor decline and parkinson-like symptoms in affected individuals.

2.
Am J Med Genet A ; 182(11): 2761-2764, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32902107

RESUMO

Bi-allelic loss-of-function variants in LAMC3, encoding extracellular matrix protein laminin gamma 3, represent a rare cause of occipital polymicrogyria with epilepsy, developmental delay and cognitive impairment. So far, only five families have been reported. We now identified a novel, homozygous splice variant in LAMC3 in an individual with an unusual manifestation of cortical malformation. She presented with polymicrogyria in the frontal but not the occipital lobes, with adult-onset seizures and normal psychomotor development and cognition. Additionally, ictal asystole, requiring implantation of a pacemaker, and nonepileptic seizures occurred. This case expands the spectrum of LAMC3-associated cortical malformation phenotypes to frontal only polymicrogyria and adult-onset of epilepsy.

3.
Am J Hum Genet ; 107(3): 527-538, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32758447

RESUMO

Generalized pustular psoriasis (GPP) is a severe multi-systemic inflammatory disease characterized by neutrophilic pustulosis and triggered by pro-inflammatory IL-36 cytokines in skin. While 19%-41% of affected individuals harbor bi-allelic mutations in IL36RN, the genetic cause is not known in most cases. To identify and characterize new pathways involved in the pathogenesis of GPP, we performed whole-exome sequencing in 31 individuals with GPP and demonstrated effects of mutations in MPO encoding the neutrophilic enzyme myeloperoxidase (MPO). We discovered eight MPO mutations resulting in MPO -deficiency in neutrophils and monocytes. MPO mutations, primarily those resulting in complete MPO deficiency, cumulatively associated with GPP (p = 1.85E-08; OR = 6.47). The number of mutant MPO alleles significantly differed between 82 affected individuals and >4,900 control subjects (p = 1.04E-09); this effect was stronger when including IL36RN mutations (1.48E-13) and correlated with a younger age of onset (p = 0.0018). The activity of four proteases, previously implicated as activating enzymes of IL-36 precursors, correlated with MPO deficiency. Phorbol-myristate-acetate-induced formation of neutrophil extracellular traps (NETs) was reduced in affected cells (p = 0.015), and phagocytosis assays in MPO-deficient mice and human cells revealed altered neutrophil function and impaired clearance of neutrophils by monocytes (efferocytosis) allowing prolonged neutrophil persistence in inflammatory skin. MPO mutations contribute significantly to GPP's pathogenesis. We implicate MPO as an inflammatory modulator in humans that regulates protease activity and NET formation and modifies efferocytosis. Our findings indicate possible implications for the application of MPO inhibitors in cardiovascular diseases. MPO and affected pathways represent attractive targets for inducing resolution of inflammation in neutrophil-mediated skin diseases.


Assuntos
Inflamação/genética , Interleucinas/genética , Peroxidase/genética , Psoríase/genética , Dermatopatias/genética , Adulto , Animais , Citocinas/genética , Armadilhas Extracelulares/genética , Feminino , Humanos , Inflamação/patologia , Interleucina-1/genética , Interleucinas/metabolismo , Masculino , Camundongos , Mutação/genética , Neutrófilos/metabolismo , Psoríase/patologia , Doenças Raras/enzimologia , Doenças Raras/genética , Doenças Raras/patologia , Pele/enzimologia , Pele/patologia , Dermatopatias/patologia
4.
Eur J Med Genet ; 63(9): 103998, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32622959

RESUMO

Autosomal-recessive spinocerebellar ataxia type 18 (SCAR18) is a rare neurologic disorder. It is caused by bi-allelic aberrations in the GRID2 gene, encoding an ionotropic glutamate receptor. In total, 20 affected individuals with mainly homozygous/compound heterozygous intragenic deletions/duplications, two different missense variants and one nonsense variant in GRID2 have been reported, so far. SCAR18 is characterized by delayed psychomotor development, intellectual disability, severely impaired gait due to cerebellar ataxia, ocular movement abnormalities, and cerebellar atrophy in brain imaging. By trio exome sequencing, we now identified a novel homozygous nonsense variant (c.568C > T; p.Gln190*) in GRID2 in a four year old female from a consanguineous family who presented with a particularly severe manifestation of SCAR18. The girl was born after an uneventful pregnancy and showed early-onset, profoundly delayed psychomotor development with no achieved psychomotor milestones at age 4 years. Additionally, she presented with severe muscular hypotonia, progressive truncal and appendicular ataxia, binocular vertical nystagmus, central hearing loss and incomplete loss of sight. She was dystrophic, interacted only very little and had behavioral anomalies such as eating hair and bruxism. Brain imaging showed cerebellar hypoplasia, extended cerebrospinal fluid spaces and beginning reduction of cerebral volume. Our findings further delineate the mutational and clinical spectrum of GRID2-associated spinocerebellar ataxia type 18 and indicate that homozygous nonsense variants are possibly associated with the severe end of the SCAR18 phenotypic spectrum.

5.
Genet Med ; 22(3): 538-546, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31723249

RESUMO

PURPOSE: Intellectual disability (ID) and autism spectrum disorder (ASD) are genetically heterogeneous neurodevelopmental disorders. We sought to delineate the clinical, molecular, and neuroimaging spectrum of a novel neurodevelopmental disorder caused by variants in the zinc finger protein 292 gene (ZNF292). METHODS: We ascertained a cohort of 28 families with ID due to putatively pathogenic ZNF292 variants that were identified via targeted and exome sequencing. Available data were analyzed to characterize the canonical phenotype and examine genotype-phenotype relationships. RESULTS: Probands presented with ID as well as a spectrum of neurodevelopmental features including ASD, among others. All ZNF292 variants were de novo, except in one family with dominant inheritance. ZNF292 encodes a highly conserved zinc finger protein that acts as a transcription factor and is highly expressed in the developing human brain supporting its critical role in neurodevelopment. CONCLUSION: De novo and dominantly inherited variants in ZNF292 are associated with a range of neurodevelopmental features including ID and ASD. The clinical spectrum is broad, and most individuals present with mild to moderate ID with or without other syndromic features. Our results suggest that variants in ZNF292 are likely a recurrent cause of a neurodevelopmental disorder manifesting as ID with or without ASD.

6.
BMC Musculoskelet Disord ; 20(1): 553, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31747907

RESUMO

BACKGROUND: Camptocormia has been reported in a plethora of diseases comprising disorders of the central nervous system, the peripheral nervous system, and the neuromuscular junction as well as hereditary and acquired myopathies. In sporadic late onset nemaline myopathy concomitant axial myopathy is common, but reports about camptocormia as the only presenting symptom in this condition are very rare. Notably, sporadic late onset nemaline myopathy is a potentially treatable condition in particular when associated with monoclonal gammopathy of unknown significance, HIV or rheumatological disorders. CASE PRESENTATION: We report the case of a 62-year-old female patient, who presented with slowly progressive camptocormia. Comprehensive work-up including neurological work-up, laboratory tests, MR-imaging, muscle biopsy and genetic testing led to the diagnosis of sporadic late onset nemaline myopathy. CONCLUSIONS: Our case report highlights that sporadic late onset nemaline myopathy has to be considered in patients presenting with isolated camptocormia and comprehensive work-up of camptocormia is mandatory to ascertain the individual diagnosis, especially in consideration of treatable conditions.


Assuntos
Atrofia Muscular Espinal/diagnóstico por imagem , Atrofia Muscular Espinal/etiologia , Miopatias da Nemalina/complicações , Miopatias da Nemalina/diagnóstico por imagem , Curvaturas da Coluna Vertebral/diagnóstico por imagem , Curvaturas da Coluna Vertebral/etiologia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade
7.
Prenat Diagn ; 39(12): 1136-1147, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31498910

RESUMO

OBJECTIVE: 17q12 microdeletions containing HNF1B and intragenic variants within this gene are associated with variable developmental, endocrine, and renal anomalies, often already noted prenatally as hyperechogenic/cystic kidneys. Here, we describe prenatal and postnatal phenotypes of seven individuals with HNF1B aberrations and compare their clinical and genetic data to those of previous studies. METHODS: Prenatal sequencing and postnatal chromosomal microarray analysis were performed in seven individuals with renal and/or neurodevelopmental phenotypes. We evaluated HNF1B-related clinical features from 82 studies and reclassified 192 reported intragenic HNF1B variants. RESULTS: In a prenatal case, we identified a novel in-frame deletion p.(Gly239del) within the HNF1B DNA-binding domain, a mutational hot spot as demonstrated by spatial clustering analysis and high computational prediction scores. The six postnatally diagnosed individuals harbored 17q12 microdeletions. Literature screening revealed variable reporting of HNF1B-associated clinical traits. Overall, both mutation groups showed a high phenotypic heterogeneity. The reclassification of all previously reported intragenic HNF1B variants provided an up-to-date overview of the mutational spectrum. CONCLUSIONS: We highlight the value of prenatal HNF1B screening in renal developmental diseases. Standardized clinical reporting and systematic classification of HNF1B variants are necessary for a more accurate risk quantification of prenatal and postnatal clinical features, improving genetic counseling and prenatal decision making.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Fator 1-beta Nuclear de Hepatócito/genética , Doenças Renais Císticas/diagnóstico , Análise em Microsséries , Diagnóstico Pré-Natal/métodos , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Adulto , Criança , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Estudos de Coortes , Hibridização Genômica Comparativa/métodos , Análise Mutacional de DNA/métodos , Diagnóstico Diferencial , Feminino , Humanos , Recém-Nascido , Doenças Renais Císticas/genética , Masculino , Análise em Microsséries/métodos , Mutação , Gravidez , Síndrome
8.
PLoS Genet ; 15(4): e1008088, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31034465

RESUMO

PIK3C2A is a class II member of the phosphoinositide 3-kinase (PI3K) family that catalyzes the phosphorylation of phosphatidylinositol (PI) into PI(3)P and the phosphorylation of PI(4)P into PI(3,4)P2. At the cellular level, PIK3C2A is critical for the formation of cilia and for receptor mediated endocytosis, among other biological functions. We identified homozygous loss-of-function mutations in PIK3C2A in children from three independent consanguineous families with short stature, coarse facial features, cataracts with secondary glaucoma, multiple skeletal abnormalities, neurological manifestations, among other findings. Cellular studies of patient-derived fibroblasts found that they lacked PIK3C2A protein, had impaired cilia formation and function, and demonstrated reduced proliferative capacity. Collectively, the genetic and molecular data implicate mutations in PIK3C2A in a new Mendelian disorder of PI metabolism, thereby shedding light on the critical role of a class II PI3K in growth, vision, skeletal formation and neurological development. In particular, the considerable phenotypic overlap, yet distinct features, between this syndrome and Lowe's syndrome, which is caused by mutations in the PI-5-phosphatase OCRL, highlight the key role of PI metabolizing enzymes in specific developmental processes and demonstrate the unique non-redundant functions of each enzyme. This discovery expands what is known about disorders of PI metabolism and helps unravel the role of PIK3C2A and class II PI3Ks in health and disease.


Assuntos
Doenças do Desenvolvimento Ósseo/genética , Catarata/genética , Transtornos da Motilidade Ciliar/genética , Nanismo/genética , Mutação , Fosfatidilinositol 3-Quinases/genética , Adolescente , Adulto , Criança , Consanguinidade , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Linhagem , Fenótipo , Adulto Jovem
9.
Eur J Hum Genet ; 27(7): 1061-1071, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30809043

RESUMO

Height is a heritable and highly heterogeneous trait. Short stature affects 3% of the population and in most cases is genetic in origin. After excluding known causes, 67% of affected individuals remain without diagnosis. To identify novel candidate genes for short stature, we performed exome sequencing in 254 unrelated families with short stature of unknown cause and identified variants in 63 candidate genes in 92 (36%) independent families. Based on systematic characterization of variants and functional analysis including expression in chondrocytes, we classified 13 genes as strong candidates. Whereas variants in at least two families were detected for all 13 candidates, two genes had variants in 6 (UBR4) and 8 (LAMA5) families, respectively. To facilitate their characterization, we established a clustered network of 1025 known growth and short stature genes, which yielded 29 significantly enriched clusters, including skeletal system development, appendage development, metabolic processes, and ciliopathy. Eleven of the candidate genes mapped to 21 of these clusters, including CPZ, EDEM3, FBRS, IFT81, KCND1, PLXNA3, RASA3, SLC7A8, UBR4, USP45, and ZFHX3. Fifty additional growth-related candidates we identified await confirmation in other affected families. Our study identifies Mendelian forms of growth retardation as an important component of idiopathic short stature.


Assuntos
Nanismo/genética , Exoma , Herança Multifatorial , Criança , Pré-Escolar , Proteínas do Citoesqueleto/genética , Feminino , Humanos , Lactente , Masculino , Sequenciamento Completo do Exoma
10.
Epileptic Disord ; 21(1): 122-127, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30782583

RESUMO

Focal cortical dysplasia is a common cause of medically refractory epilepsy in infancy and childhood. We report a neonate with seizures occurring within the first day of life. Continuous video-EEG monitoring led to detection of left motor seizures and a right frontal EEG seizure pattern. Brain MRI revealed a lesion within the right frontal lobe without contrast enhancement. The patient was referred for epilepsy surgery due to drug resistance to vitamin B6 and four antiepileptic drugs. Lesionectomy was performed at the age of two and a half months, and histopathological evaluation confirmed the diagnosis of focal cortical dysplasia type IIb (FCD IIb). The patient is free of unprovoked seizures without medication (Engel Class I) and is normally developed at 36 months after surgery. The case study demonstrates that FCD IIb may cause seizures within the first day of life and that epilepsy surgery can be successfully performed in medically intractable patients with a clearly identifiable seizure onset zone within the first three months of life. Although radical surgery such as hemispherectomy and multi-lobar resections are over-represented in early infancy, this case also illustrates a favourable outcome with a more limited resection in this age group.


Assuntos
Epilepsia Resistente a Medicamentos/cirurgia , Malformações do Desenvolvimento Cortical do Grupo II/cirurgia , Pré-Escolar , Epilepsia Resistente a Medicamentos/diagnóstico , Epilepsia Resistente a Medicamentos/etiologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Eletroencefalografia , Feminino , Humanos , Imagem por Ressonância Magnética , Malformações do Desenvolvimento Cortical do Grupo II/complicações , Malformações do Desenvolvimento Cortical do Grupo II/diagnóstico
11.
Orphanet J Rare Dis ; 14(1): 38, 2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30744660

RESUMO

BACKGROUND: The TUBA1A-associated tubulinopathy is clinically heterogeneous with brain malformations, microcephaly, developmental delay and epilepsy being the main clinical features. It is an autosomal dominant disorder mostly caused by de novo variants in TUBA1A. RESULTS: In three individuals with developmental delay we identified heterozygous de novo missense variants in TUBA1A using exome sequencing. While the c.1307G > A, p.(Gly436Asp) variant was novel, the two variants c.518C > T, p.(Pro173Leu) and c.641G > A, p.(Arg214His) were previously described. We compared the variable phenotype observed in these individuals with a carefully conducted review of the current literature and identified 166 individuals, 146 born and 20 fetuses with a TUBA1A variant. In 107 cases with available clinical information we standardized the reported phenotypes according to the Human Phenotype Ontology. The most commonly reported features were developmental delay (98%), anomalies of the corpus callosum (96%), microcephaly (76%) and lissencephaly (agyria-pachygyria) (70%), although reporting was incomplete in the different studies. We identified a total of 121 specific variants, including 15 recurrent ones. Missense variants cluster in the C-terminal region around the most commonly affected amino acid position Arg402 (13.3%). In a three-dimensional protein model, 38.6% of all disease-causing variants including those in the C-terminal region are predicted to affect the binding of microtubule-associated proteins or motor proteins. Genotype-phenotype analysis for recurrent variants showed an overrepresentation of certain clinical features. However, individuals with these variants are often reported in the same publication. CONCLUSIONS: With 166 individuals, we present the most comprehensive phenotypic and genotypic standardized synopsis for clinical interpretation of TUBA1A variants. Despite this considerable number, a detailed genotype-phenotype characterization is limited by large inter-study variability in reporting.


Assuntos
Tubulina (Proteína)/genética , Adolescente , Criança , Corpo Caloso/metabolismo , Corpo Caloso/patologia , Feminino , Genótipo , Humanos , Lisencefalia/genética , Lisencefalia/patologia , Masculino , Microcefalia/genética , Microcefalia/patologia , Mutação de Sentido Incorreto/genética , Fenótipo
12.
Int J Cancer ; 145(4): 941-951, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30694527

RESUMO

Two percent of patients with Wilms tumors have a positive family history. In many of these cases the genetic cause remains unresolved. By applying germline exome sequencing in two families with two affected individuals with Wilms tumors, we identified truncating mutations in TRIM28. Subsequent mutational screening of germline and tumor DNA of 269 children affected by Wilms tumor was performed, and revealed seven additional individuals with germline truncating mutations, and one individual with a somatic truncating mutation in TRIM28. TRIM28 encodes a complex scaffold protein involved in many different processes, including gene silencing, DNA repair and maintenance of genomic integrity. Expression studies on mRNA and protein level showed reduction of TRIM28, confirming a loss-of-function effect of the mutations identified. The tumors showed an epithelial-type histology that stained negative for TRIM28 by immunohistochemistry. The tumors were bilateral in six patients, and 10/11 tumors are accompanied by perilobar nephrogenic rests. Exome sequencing on eight tumor DNA samples from six individuals showed loss-of-heterozygosity (LOH) of the TRIM28-locus by mitotic recombination in seven tumors, suggesting that TRIM28 functions as a tumor suppressor gene in Wilms tumor development. Additionally, the tumors showed very few mutations in known Wilms tumor driver genes, suggesting that loss of TRIM28 is the main driver of tumorigenesis. In conclusion, we identified heterozygous germline truncating mutations in TRIM28 in 11 children with mainly epithelial-type Wilms tumors, which become homozygous in tumor tissue. These data establish TRIM28 as a novel Wilms tumor predisposition gene, acting as a tumor suppressor gene by LOH.


Assuntos
Haploinsuficiência/genética , Proteína 28 com Motivo Tripartido/genética , Tumor de Wilms/genética , Carcinogênese/genética , Pré-Escolar , DNA de Neoplasias/genética , Feminino , Genes do Tumor de Wilms/fisiologia , Predisposição Genética para Doença/genética , Genótipo , Mutação em Linhagem Germinativa/genética , Heterozigoto , Humanos , Lactente , Neoplasias Renais/genética , Mutação com Perda de Função/genética , Perda de Heterozigosidade/genética , Masculino , Sequenciamento Completo do Exoma/métodos
13.
Am J Med Genet A ; 179(1): 50-56, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30548383

RESUMO

Biallelic variants in the AEBP1 gene cause a novel autosomal-recessive connective tissue disorder (CTD) reminiscent of Ehlers-Danlos Syndrome (EDS). The four previously reported individuals show considerable clinical variability. Unbiased high-throughput sequencing enables the rapid identification of additional cases for such rare entities. We identified the homozygous nonsense variant c.917dup, p.Tyr306* in AEBP1 using clinical exome sequencing in a female individual with previously unsolved CTD. Segregation testing confirmed homozygosity in the clinically affected brother and heterozygous carrier status in the healthy mother. Chromosomal microarray showed that the variant lies in a run of homozygosity, suggesting a common origin of this genomic segment. RT-PCR analysis in the mother revealed a monoallelic expression of the normal transcript supporting a nonsense-mediated mRNA decay and functional nullizygosity as disease mechanism. We describe two individuals from a fourth family with AEBP1-associated CTD. Our results further verify that autosomal-recessive inherited LOF variants in the AEBP1 gene cause clinical features of different EDS subtypes, but also of the marfanoid spectrum. As identification of further individuals is necessary to inform the clinical characterization, we stress the added value of exome sequencing for such rare diseases.


Assuntos
Carboxipeptidases/genética , Doenças do Tecido Conjuntivo/genética , Síndrome de Ehlers-Danlos/genética , Predisposição Genética para Doença , Proteínas Repressoras/genética , Adulto , Códon sem Sentido/genética , Tecido Conjuntivo/metabolismo , Tecido Conjuntivo/patologia , Doenças do Tecido Conjuntivo/fisiopatologia , Síndrome de Ehlers-Danlos/fisiopatologia , Exoma/genética , Feminino , Genes Recessivos , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Mutação com Perda de Função/genética , Masculino , Linhagem , Fenótipo , Irmãos
14.
Am J Med Genet A ; 176(12): 2872-2876, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30450806

RESUMO

Mutations in BCOR cause X-linked dominant and X-linked recessive forms of syndromic microphthalmia. By exome sequencing, we identified the recurrent BCOR mutation p.Pro85Leu in two brothers and their unaffected mother. While the older brother's phenotype completely fits the described phenotypic spectrum of X-linked recessive BCOR-associated Lenz microphthalmia syndrome, the younger brother showed developmental delay, microcephaly, and skeletal anomalies, but not the key feature of microphthalmia. In contrast to the previously published families, our findings demonstrate a large variability of BCOR-associated, syndromic phenotypes, indicating incomplete penetrance of p.Pro85Leu with regards to microphthalmia in males.


Assuntos
Substituição de Aminoácidos , Anoftalmia/diagnóstico , Anoftalmia/genética , Microftalmia/diagnóstico , Microftalmia/genética , Mutação , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Análise Mutacional de DNA , Diagnóstico Diferencial , Feminino , Genes Ligados ao Cromossomo X , Humanos , Imagem por Ressonância Magnética , Masculino , Linhagem , Penetrância , Fenótipo
15.
BMC Cancer ; 18(1): 926, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30257646

RESUMO

BACKGROUND: Breast cancer is the most common cancer in women. 12-15% of all tumors are triple-negative breast cancers (TNBC). So far, TNBC has been mainly associated with mutations in BRCA1. The presence of other predisposing genes seems likely since DNA damage repair is a complex process that involves several genes. Therefore we investigated if mutations in other genes are involved in cancer development and whether TNBC is an additional indicator of mutational status besides family history and age of onset. METHODS: We performed a germline panel-based screening of 10 high and low-moderate penetrance breast cancer susceptibility genes (BRCA1, BRCA2, ATM, CDH1, CHEK2, NBN, PALB2, RAD51C, RAD51D and TP53) in 229 consecutive individuals affected with TNBC unselected for age, family history or bilateral disease. Within this cohort we compared the number of mutation carriers fulfilling clinical selection criteria with the total number of carriers identified. RESULTS: Age at diagnosis ranged from 23 to 80 years with an average age of 50.2 years. In 57 women (24.9%) we detected a pathogenic mutation, with a higher frequency (29.7%) in the group manifesting cancer before 60 years. Deleterious BRCA1 mutations occurred in 14.8% of TNBC patients. These were predominantly recurrent frameshift mutations (24/34, 70.6%). Deleterious BRCA2 mutations occurred in 5.7% of patients, all but one (c.1813dupA) being unique. While no mutations were found in CDH1 and TP53, 10 mutations were detected in one of the six other predisposition genes. Remarkably, neither of the ATM, RAD51D, CHEK2 and PALB2 mutation carriers had a family history. Furthermore, patients with non-BRCA1/2 mutations were not significantly younger than mutation negative women (p = 0.3341). Most importantly, among the 57 mutation carriers, ten (17.5%) would be missed using current clinical testing criteria including five (8%) with BRCA1/2 mutations. CONCLUSIONS: In summary, our data confirm and expand previous studies of a high frequency of germline mutations in genes associated with ineffective repair of DNA damage in women with TNBCs. Neither age of onset, contralateral disease nor family history were able to discern all mutation positive individuals. Therefore, TNBC should be considered as an additional criterion for panel based genetic testing.


Assuntos
Análise Mutacional de DNA/métodos , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Neoplasias de Mama Triplo Negativas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Seleção de Pacientes , Penetrância , Análise de Sequência de DNA , Adulto Jovem
16.
J Cell Sci ; 131(16)2018 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-30054381

RESUMO

Pericentrin (Pcnt) is a multifunctional scaffold protein and mutations in the human PCNT gene are associated with several diseases, including ciliopathies. Pcnt plays a crucial role in ciliary development in olfactory receptor neurons, but its function in the photoreceptor-connecting cilium is unknown. We downregulated Pcnt in the retina ex vivo and in vivo via a virus-based RNA interference approach to study Pcnt function in photoreceptors. ShRNA-mediated knockdown of Pcnt impaired the development of the connecting cilium and the outer segment of photoreceptors, and caused a nuclear migration defect. In protein interaction screens, we found that the outer nuclear membrane protein Syne-2 (also known as Nesprin-2) is an interaction partner of Pcnt in photoreceptors. Syne-2 is important for positioning murine photoreceptor cell nuclei and for centrosomal migration during early ciliogenesis. CRISPR/Cas9-mediated knockout of Syne-2 in cell culture led to an overexpression and mislocalization of Pcnt and to ciliogenesis defects. Our findings suggest that the Pcnt-Syne-2 complex is important for ciliogenesis and outer segment formation during retinal development and plays a role in nuclear migration.


Assuntos
Antígenos/fisiologia , Cílios/fisiologia , Proteínas dos Microfilamentos/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Proteínas Nucleares/fisiologia , Organogênese/genética , Animais , Antígenos/genética , Sistemas CRISPR-Cas , Células Cultivadas , Cílios/genética , Feminino , Técnicas de Inativação de Genes , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas dos Microfilamentos/genética , Células NIH 3T3 , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Retina/embriologia , Retina/metabolismo
17.
Neurogenetics ; 19(4): 215-225, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30039206

RESUMO

Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family with axonal neuropathy and autosomal recessive pattern of inheritance (CMT2B2). We proposed a homozygous missense variant in the Mediator complex 25 (MED25) gene as causative of the disease. Nevertheless, the fact that no other CMT individuals with MED25 variants were reported to date led us to reevaluate the original family. Using exome sequencing, we now identified a homozygous nonsense variant (p.Gln517ter) in the last exon of an adjacent gene, the polynucleotide kinase 3'-phosphatase (PNKP) gene. It encodes a DNA repair protein recently associated with recessive ataxia with oculomotor apraxia type 4 (AOA4) and microcephaly, seizures, and developmental delay (MCSZ). Subsequently, five unrelated Costa Rican CMT2 subjects initially identified as being heterozygous for the same MED25 variant were found to be also compound heterozygote for PNKP. All were heterozygous for the same variant found homozygous in the large family and a second one previously associated with ataxia (p.Thr408del). Detailed clinical reassessment of the initial family and the new individuals revealed in all an adult-onset slowly progressive CMT2 associated with signs of cerebellar dysfunction such as slurred speech and oculomotor involvement, but neither microcephaly, seizures, nor developmental delay. We propose that PKNP variants are the major causative variant for the CMT2 phenotype in these individuals and that the milder clinical manifestation is due to an allelic effect.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Enzimas Reparadoras do DNA/genética , Complexo Mediador/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Adulto , Substituição de Aminoácidos/genética , Estudos de Casos e Controles , Consanguinidade , Costa Rica , Análise Mutacional de DNA , Enzimas Reparadoras do DNA/química , Família , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Mutação de Sentido Incorreto , Linhagem , Fosfotransferases (Aceptor do Grupo Álcool)/química , Polimorfismo de Nucleotídeo Único
18.
Eur J Hum Genet ; 26(8): 1113-1120, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29706635

RESUMO

Height is a complex quantitative trait with a high heritability. Short stature is diagnosed when height is significantly below the average of the general population for that person's age and sex. We have recently found that the retinoic acid degrading enzyme CYP26C1 modifies SHOX deficiency phenotypes toward more severe clinical manifestations. Here, we asked whether damaging variants in CYP26C1 alone could lead to short stature. We performed exome and Sanger sequencing to analyze 856 individuals with short stature where SHOX deficiency was previously excluded. Three different damaging missense variants and one splicing variant were identified in six independent individuals; the functional significance of the identified variants was tested in vitro or in vivo using zebrafish as a model. The genetic and functional data reported here indicate that CYP26C1 represents a novel gene underlying growth disorders and that damaging variants in the absence of SHOX variants can lead to short stature.


Assuntos
Família 26 do Citocromo P450/genética , Nanismo Hipofisário/genética , Mutação de Sentido Incorreto , Adolescente , Adulto , Animais , Linhagem Celular Tumoral , Criança , Família 26 do Citocromo P450/metabolismo , Nanismo Hipofisário/patologia , Exoma , Feminino , Humanos , Masculino , Processamento de RNA , Peixe-Zebra
19.
Genet Med ; 20(6): 630-638, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29758562

RESUMO

PurposeShort stature is a common condition of great concern to patients and their families. Mostly genetic in origin, the underlying cause often remains elusive due to clinical and genetic heterogeneity.MethodsWe systematically phenotyped 565 patients where common nongenetic causes of short stature were excluded, selected 200 representative patients for whole-exome sequencing, and analyzed the identified variants for pathogenicity and the affected genes regarding their functional relevance for growth.ResultsBy standard targeted diagnostic and phenotype assessment, we identified a known disease cause in only 13.6% of the 565 patients. Whole-exome sequencing in 200 patients identified additional mutations in known short-stature genes in 16.5% of these patients who manifested only part of the symptomatology. In 15.5% of the 200 patients our findings were of significant clinical relevance. Heterozygous carriers of recessive skeletal dysplasia alleles represented 3.5% of the cases.ConclusionA combined approach of systematic phenotyping, targeted genetic testing, and whole-exome sequencing allows the identification of the underlying cause of short stature in at least 33% of cases, enabling physicians to improve diagnosis, treatment, and genetic counseling. Exome sequencing significantly increases the diagnostic yield and consequently care in patients with short stature.


Assuntos
Estatura/genética , Feminino , Testes Genéticos , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mutação , Linhagem , Fenótipo , Análise de Sequência de DNA/métodos , Sequenciamento Completo do Exoma/métodos
20.
Eur J Med Genet ; 61(7): 363-368, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29407414

RESUMO

3MC syndrome is a rare autosomal recessive disorder with characteristic craniofacial dysmorphism and multiple anomalies. It is caused by biallelic mutations in one of three genes, MASP1, COLEC11 and COLEC10, all encoding factors of the lectin complement pathway. In MASP1, either truncating mutations or missense variants in exon 12 encoding the C-terminal serine protease domain specific for isoform MASP-3 are causative. By trio exome sequencing we now identified a novel, homozygous 2kb deletion, partially affecting exon 12 in an adult female with the typical facial gestalt of 3MC syndrome and hearing loss, but without the main feature cleft lip/palate, and without intellectual disability, or short stature. We therefore expand the MASP1 associated mutational and clinical spectrum and describe the development of her clinical presentation over a period of 21 years. As the homozygous deletion in our patient was only found by thorough and visual evaluation of the whole exome sequencing data, such deletions might escape detection in some routine diagnostic workflows and might explain a few of the so far molecularly unconfirmed cases of 3MC syndrome.


Assuntos
Anormalidades Múltiplas/genética , Anormalidades Craniofaciais/genética , Serina Proteases Associadas a Proteína de Ligação a Manose/genética , Adulto , Face/anormalidades , Feminino , Deleção de Genes , Humanos , Síndrome , Sequenciamento Completo do Exoma , Adulto Jovem
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