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1.
Sci Rep ; 9(1): 15739, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673062

RESUMO

Reticular dysgenesis is an autosomal recessive form of severe combined immunodeficiency (SCID) that usually manifests in newborns. It is a unique example of an immune deficiency that is linked to dysfunctional mitochondrial energy metabolism and caused by adenylate kinase 2 (AK2) deficiency. It is characterized by an early differentiation arrest in the myeloid lineage, impaired lymphoid maturation, and sensorineural hearing loss. In this study, a novel AK2 homozygous mutation, c.622 T > C [p.Ser208Pro], was identified in an Old Order Amish patient through whole exome sequencing. Functional studies showed that the patient's cells have no detectable AK2 protein, as well as low oxygen consumption rate (OCR), extracellular acidification rate (ECAR) and proton production rate (PPR). An increased production of reactive oxygen species, mitochondrial membrane permeability, and mitochondrial mass, and decreased ATP production, were also observed. The results confirm the pathogenicity of the AK2 mutation and demonstrate that reticular dysgenesis should be considered in Amish individuals presenting with immune deficiency. We also describe other pathophysiological aspects of AK2 deficiency not previously reported.

2.
Mol Autism ; 10: 35, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31649809

RESUMO

Background: PHF21A has been associated with intellectual disability and craniofacial anomalies based on its deletion in the Potocki-Shaffer syndrome region at 11p11.2 and its disruption in three patients with balanced translocations. In addition, three patients with de novo truncating mutations in PHF21A were reported recently. Here, we analyze genomic data from seven unrelated individuals with mutations in PHF21A and provide detailed clinical descriptions, further expanding the phenotype associated with PHF21A haploinsufficiency. Methods: Diagnostic trio whole exome sequencing, Sanger sequencing, use of GeneMatcher, targeted gene panel sequencing, and MiSeq sequencing techniques were used to identify and confirm variants. RT-qPCR was used to measure the normal expression pattern of PHF21A in multiple human tissues including 13 different brain tissues. Protein-DNA modeling was performed to substantiate the pathogenicity of the missense mutation. Results: We have identified seven heterozygous coding mutations, among which six are de novo (not maternal in one). Mutations include four frameshifts, one nonsense mutation in two patients, and one heterozygous missense mutation in the AT Hook domain, predicted to be deleterious and likely to cause loss of PHF21A function. We also found a new C-terminal domain composed of an intrinsically disordered region. This domain is truncated in six patients and thus likely to play an important role in the function of PHF21A, suggesting that haploinsufficiency is the likely underlying mechanism in the phenotype of seven patients. Our results extend the phenotypic spectrum of PHF21A mutations by adding autism spectrum disorder, epilepsy, hypotonia, and neurobehavioral problems. Furthermore, PHF21A is highly expressed in the human fetal brain, which is consistent with the neurodevelopmental phenotype. Conclusion: Deleterious nonsense, frameshift, and missense mutations disrupting the AT Hook domain and/or an intrinsically disordered region in PHF21A were found to be associated with autism spectrum disorder, epilepsy, hypotonia, neurobehavioral problems, tapering fingers, clinodactyly, and syndactyly, in addition to intellectual disability and craniofacial anomalies. This suggests that PHF21A is involved in autism spectrum disorder and intellectual disability, and its haploinsufficiency causes a diverse neurological phenotype.

3.
Biol Psychiatry ; 2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31443933

RESUMO

BACKGROUND: The X-chromosome gene USP9X encodes a deubiquitylating enzyme that has been associated with neurodevelopmental disorders primarily in female subjects. USP9X escapes X inactivation, and in female subjects de novo heterozygous copy number loss or truncating mutations cause haploinsufficiency culminating in a recognizable syndrome with intellectual disability and signature brain and congenital abnormalities. In contrast, the involvement of USP9X in male neurodevelopmental disorders remains tentative. METHODS: We used clinically recommended guidelines to collect and interrogate the pathogenicity of 44 USP9X variants associated with neurodevelopmental disorders in males. Functional studies in patient-derived cell lines and mice were used to determine mechanisms of pathology. RESULTS: Twelve missense variants showed strong evidence of pathogenicity. We define a characteristic phenotype of the central nervous system (white matter disturbances, thin corpus callosum, and widened ventricles); global delay with significant alteration of speech, language, and behavior; hypotonia; joint hypermobility; visual system defects; and other common congenital and dysmorphic features. Comparison of in silico and phenotypical features align additional variants of unknown significance with likely pathogenicity. In support of partial loss-of-function mechanisms, using patient-derived cell lines, we show loss of only specific USP9X substrates that regulate neurodevelopmental signaling pathways and a united defect in transforming growth factor ß signaling. In addition, we find correlates of the male phenotype in Usp9x brain-specific knockout mice, and further resolve loss of hippocampal-dependent learning and memory. CONCLUSIONS: Our data demonstrate the involvement of USP9X variants in a distinctive neurodevelopmental and behavioral syndrome in male subjects and identify plausible mechanisms of pathogenesis centered on disrupted transforming growth factor ß signaling and hippocampal function.

4.
Genet Med ; 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31263215

RESUMO

PURPOSE: Haploinsufficiency of DYRK1A causes a recognizable clinical syndrome. The goal of this paper is to investigate congenital anomalies of the kidney and urinary tract (CAKUT) and genital defects (GD) in patients with DYRK1A variants. METHODS: A large database of clinical exome sequencing (ES) was queried for de novo DYRK1A variants and CAKUT/GD phenotypes were characterized. Xenopus laevis (frog) was chosen as a model organism to assess Dyrk1a's role in renal development. RESULTS: Phenotypic details and variants of 19 patients were compiled after an initial observation that one patient with a de novo pathogenic variant in DYRK1A had GD. CAKUT/GD data were available from 15 patients, 11 of whom presented with CAKUT/GD. Studies in Xenopus embryos demonstrated that knockdown of Dyrk1a, which is expressed in forming nephrons, disrupts the development of segments of embryonic nephrons, which ultimately give rise to the entire genitourinary (GU) tract. These defects could be rescued by coinjecting wild-type human DYRK1A RNA, but not with DYRK1AR205* or DYRK1AL245R RNA. CONCLUSION: Evidence supports routine GU screening of all individuals with de novo DYRK1A pathogenic variants to ensure optimized clinical management. Collectively, the reported clinical data and loss-of-function studies in Xenopus substantiate a novel role for DYRK1A in GU development.

5.
Am J Hum Genet ; 104(1): 164-178, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30580808

RESUMO

SMARCC2 (BAF170) is one of the invariable core subunits of the ATP-dependent chromatin remodeling BAF (BRG1-associated factor) complex and plays a crucial role in embryogenesis and corticogenesis. Pathogenic variants in genes encoding other components of the BAF complex have been associated with intellectual disability syndromes. Despite its significant biological role, variants in SMARCC2 have not been directly associated with human disease previously. Using whole-exome sequencing and a web-based gene-matching program, we identified 15 individuals with variable degrees of neurodevelopmental delay and growth retardation harboring one of 13 heterozygous variants in SMARCC2, most of them novel and proven de novo. The clinical presentation overlaps with intellectual disability syndromes associated with other BAF subunits, such as Coffin-Siris and Nicolaides-Baraitser syndromes and includes prominent speech impairment, hypotonia, feeding difficulties, behavioral abnormalities, and dysmorphic features such as hypertrichosis, thick eyebrows, thin upper lip vermilion, and upturned nose. Nine out of the fifteen individuals harbor variants in the highly conserved SMARCC2 DNA-interacting domains (SANT and SWIRM) and present with a more severe phenotype. Two of these individuals present cardiac abnormalities. Transcriptomic analysis of fibroblasts from affected individuals highlights a group of differentially expressed genes with possible roles in regulation of neuronal development and function, namely H19, SCRG1, RELN, and CACNB4. Our findings suggest a novel SMARCC2-related syndrome that overlaps with neurodevelopmental disorders associated with variants in BAF-complex subunits.


Assuntos
Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/genética , Deficiência Intelectual/complicações , Deficiência Intelectual/genética , Mutação , Fatores de Transcrição/genética , Anormalidades Múltiplas/genética , Adolescente , Criança , Pré-Escolar , Face/anormalidades , Feminino , Deformidades Congênitas da Mão/genética , Humanos , Masculino , Micrognatismo/genética , Pescoço/anormalidades , Síndrome
6.
Genet Med ; 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30158690

RESUMO

PURPOSE: Defects in the cohesin pathway are associated with cohesinopathies, notably Cornelia de Lange syndrome (CdLS). We aimed to delineate pathogenic variants in known and candidate cohesinopathy genes from a clinical exome perspective. METHODS: We retrospectively studied patients referred for clinical exome sequencing (CES, N = 10,698). Patients with causative variants in novel or recently described cohesinopathy genes were enrolled for phenotypic characterization. RESULTS: Pathogenic or likely pathogenic single-nucleotide and insertion/deletion variants (SNVs/indels) were identified in established disease genes including NIPBL (N = 5), SMC1A (N = 14), SMC3 (N = 4), RAD21 (N = 2), and HDAC8 (N = 8). The phenotypes in this genetically defined cohort skew towards the mild end of CdLS spectrum as compared with phenotype-driven cohorts. Candidate or recently reported cohesinopathy genes were supported by de novo SNVs/indels in STAG1 (N = 3), STAG2 (N = 5), PDS5A (N = 1), and WAPL (N = 1), and one inherited SNV in PDS5A. We also identified copy-number deletions affecting STAG1 (two de novo, one of unknown inheritance) and STAG2 (one of unknown inheritance). Patients with STAG1 and STAG2 variants presented with overlapping features yet without characteristic facial features of CdLS. CONCLUSION: CES effectively identified disease-causing alleles at the mild end of the cohensinopathy spectrum and enabled characterization of candidate disease genes.

7.
Eur J Med Genet ; 2018 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30048823

RESUMO

Proper function of GABAergic synapses depends upon the postsynaptic compartment anchoring of neurotransmitter receptors to the membrane by gephyrin and collybistin (Cb). In humans, Cb is encoded by ARHGEF9 on Xq11.1. ARHGEF9 alterations, some inherited from unaffected mothers, have been reported in males with autism, seizures and severe neurodevelopmental abnormalities. In females, a spectrum of mild to moderate phenotype has been detected. We report two unrelated females with autism and mild intellectual disability. High resolution X-chromosome microarray analysis revealed de novo intragenic deletions in ARHGEF9 of 24 kb and 56 kb involving exons 5-8 and exons 3-8 and leading to truncated forms of collybistin. Peripheral blood samples revealed random X-chromosome inactivation in both patients. To explain phenotypic variability in female patients, we propose a model for disruption of collybistin and various irregular interactions in post-synaptic neurons based on X inactivation patterns. Our findings highlight the importance of ARHGEF9 integrity and suggest further research on its correlation with autism and neurobehavioral problems.

8.
Hum Genet ; 137(3): 257-264, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29556724

RESUMO

PRR12 encodes a proline-rich protein nuclear factor suspected to be involved in neural development. Its nuclear expression in fetal brains and in the vision system supports its role in brain and eye development more specifically. However, its function and potential role in human disease has not been determined. Recently, a de novo t(10;19) (q22.3;q13.33) translocation disrupting the PRR12 gene was detected in a girl with intellectual disability and neuropsychiatric alterations. Here we report on three unrelated patients with heterozygous de novo apparent loss-of-function mutations in PRR12 detected by clinical whole exome sequencing: c.1918G>T (p.Glu640*), c.4502_4505delTGCC (p.Leu1501Argfs*146) and c.903_909dup (p.Pro304Thrfs*46). All three patients had global developmental delay, intellectual disability, eye and vision abnormalities, dysmorphic features, and neuropsychiatric problems. Eye abnormalities were consistent among the three patients and consisted of stellate iris pattern and iris coloboma. Additional variable clinical features included hypotonia, skeletal abnormalities, sleeping problems, and behavioral issues such as autism and anxiety. In summary, we propose that haploinsufficiency of PRR12 is associated with this novel multisystem neurodevelopmental disorder.

9.
Am J Med Genet A ; 176(1): 187-193, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29160006

RESUMO

The "blepharophimosis-mental retardation" syndromes (BMRS) consist of a group of clinically and genetically heterogeneous congenital malformation syndromes, where short palpebral fissures and intellectual disability associate with a distinct set of other morphological features. Kaufman oculocerebrofacial syndrome represents a rare and recently reevaluated entity within the BMR syndromes and is caused by biallelic mutations of UBE3B. Affected individuals typically show microcephaly, impaired somatic growth, gastrointestinal and genitourinary problems, ectodermal anomalies and a characteristic face with short, upslanted palpebral fissures, depressed nasal bridge. and anteverted nares. Here we present four patients with five novel UBE3B mutations and propose the inclusion of clinical features to the characteristics of Kaufman oculocerebrofacial syndrome, including prominence of the cheeks and limb anomalies.


Assuntos
Anormalidades do Olho/diagnóstico , Anormalidades do Olho/genética , Estudos de Associação Genética , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Deformidades Congênitas dos Membros/diagnóstico , Deformidades Congênitas dos Membros/genética , Microcefalia/diagnóstico , Microcefalia/genética , Mutação , Fenótipo , Ubiquitina-Proteína Ligases/genética , Biomarcadores , Criança , Análise Mutacional de DNA , Diagnóstico por Imagem , Anormalidades do Olho/terapia , Facies , Feminino , Heterogeneidade Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Deficiência Intelectual/terapia , Deformidades Congênitas dos Membros/terapia , Microcefalia/terapia , Análise de Sequência de DNA
10.
Genome Med ; 9(1): 73, 2017 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-28807008

RESUMO

BACKGROUND: De novo missense variants in CDK13 have been described as the cause of syndromic congenital heart defects in seven individuals ascertained from a large congenital cardiovascular malformations cohort. We aimed to further define the phenotypic and molecular spectrum of this newly described disorder. METHODS: To minimise ascertainment bias, we recruited nine additional individuals with CDK13 pathogenic variants from clinical and research exome laboratory sequencing cohorts. Each individual underwent dysmorphology exam and comprehensive medical history review. RESULTS: We demonstrate greater than expected phenotypic heterogeneity, including 33% (3/9) of individuals without structural heart disease on echocardiogram. There was a high penetrance for a unique constellation of facial dysmorphism and global developmental delay, as well as less frequently seen renal and sacral anomalies. Two individuals had novel CDK13 variants (p.Asn842Asp, p.Lys734Glu), while the remaining seven unrelated individuals had a recurrent, previously published p.Asn842Ser variant. Summary of all variants published to date demonstrates apparent restriction of pathogenic variants to the protein kinase domain with clustering in the ATP and magnesium binding sites. CONCLUSIONS: Here we provide detailed phenotypic and molecular characterisation of individuals with pathogenic variants in CDK13 and propose management guidelines based upon the estimated prevalence of anomalies identified.


Assuntos
Proteína Quinase CDC2/genética , Face/anormalidades , Cardiopatias Congênitas/metabolismo , Deficiência Intelectual/metabolismo , Mutação , Fenótipo , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Cardiopatias Congênitas/genética , Humanos , Lactente , Deficiência Intelectual/genética , Masculino , Síndrome
11.
AJP Rep ; 7(3): e163-e166, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28765793

RESUMO

Background Though botulism is a rare disease overall, all infants younger than 1 year of age are at risk of contracting infant botulism, the most prevalent form reported in the United States. Nonetheless, infant botulism is frequently omitted from the differential diagnosis of the very young neonate exclusively due to age, and the diagnosis is often only considered secondarily after a costly and prolonged work up is undertaken. Delayed diagnosis can lead not only to unnecessary testing but also to prolonged hospital stay and increased morbidity. Case This case series highlights three critically ill neonates, all younger than 30 days, who presented to our neonatal intensive care unit and were eventually diagnosed with infant botulism. The initial diagnostic dilemma is described for each of these patients and highlights the importance of early recognition of the main symptoms, in addition to consideration of important potential coinciding conditions.

12.
Mol Cytogenet ; 10: 24, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28649281

RESUMO

BACKGROUND: Duplications or deletions in the 12q13.13 region are rare. Only scattered cases with duplications and/or deletions in this region have been reported in the literature or in online databases. Owing to the limited number of patients with genomic alteration within this region and lack of systematic analysis of these patients, the common clinical manifestation of these patients has remained elusive. CASE PRESENTATION: Here we report an 802 kb duplication in the 12q13.13q13.13 region in a 14 year-old male who presented with dysmorphic features, developmental delay (DD), mild intellectual disability (ID) and mild deformity of digits. Comparing the phenotype of our patient with those of reported patients, we find that patients with the 12q13.13 duplication or the deletion share similar phenotypes, including dysmorphic facies, abnormal nails, intellectual disability, and deformity of digits or limbs. However, patients with the deletion appear to have more severe deformity of digits or limbs. CONCLUSIONS: Deletion and duplication of the 12q13.13 region may represent novel contiguous gene alteration syndromes. All seven reported 12q13.13 deletions and three of four duplications are de novo and vary in size. Therefore, these genomic alterations are not due to non-allelic homologous recombination.

14.
Am J Med Genet A ; 2017 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-28464518

RESUMO

Congenital heart defects (CHD) are the most frequent type of congenital anomaly and are often associated with genetic and chromosomal syndromes. Haploinsufficiency of TAB2 (TGF-beta activated kinase 1/MAP3K7 binding protein 2) has been proposed to cause valvular and cardiac outflow tract structural abnormalities. In this study, we describe 13 newly identified individuals with microdeletions of chromosome 6q25.1 that involve TAB2. One of the patients in our study cohort has the smallest deletion yet reported, affecting only TAB2. These were compared to 27 other patients reported in the published literature or DECIPHER to have similar microdeletions, for a total study group of 40 patients. Our study shows that individuals with TAB2 deletions are predisposed to developing a primary cardiomyopathy with reduced systolic function, even in the absence of CHD. Our study cohort also shares a number of non-cardiac phenotypic findings: characteristic dysmorphic facial features, intrauterine growth restriction and/or postnatal proportionate short stature, hypotonia, developmental delay and/or intellectual disability, and connective tissue abnormalities. We conclude that a microdeletion of 6q25.1 that includes TAB2 causes a distinctive, multi-systemic syndrome. The 6q25.1 microdeletion syndrome should be considered in a patient with cardiomyopathy or a CHD, especially valve and/or atrial or ventricular septal abnormalities, and with phenotypic features described in this study. We recommend that patients with a TAB2 deletion be screened longitudinally for systolic heart failure, even if an initial echocardiogram is normal.

15.
J Hum Genet ; 62(6): 589-597, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28228639

RESUMO

N-methyl-d-aspartate receptors (NMDARs) play important roles in brain development and neurological disease. We report two individuals with similar dominant de novo GRIN1 mutations (c.1858 G>A and c.1858 G>C; both p.G620R). Both individuals presented at birth with developmental delay and hypotonia associated with behavioral abnormalities and stereotypical movements. Recombinant NMDARs containing the mutant GluN1-G620R together with either GluN2A or GluN2B were evaluated for changes in their trafficking to the plasma membrane and their electrophysiological properties. GluN1-G620R/GluN2A complexes showed a mild reduction in trafficking, a ~2-fold decrease in glutamate and glycine potency, a strong decrease in sensitivity to Mg2+ block, and a significant reduction of current responses to a maximal effective concentration of agonists. GluN1-G620R/GluN2B complexes showed significantly reduced delivery of protein to the cell surface associated with similarly altered electrophysiology. These results indicate these individuals may have suffered neurodevelopmental deficits as a result of the decreased presence of GluN1-G620R/GluN2B complexes on the neuronal surface during embryonic brain development and reduced current responses of GluN1-G620R-containing NMDARs after birth. These cases emphasize the importance of comprehensive functional characterization of de novo mutations and illustrates how a combination of several distinct features of NMDAR expression, trafficking and function can be present and influence phenotype.


Assuntos
Deficiência Intelectual/genética , Proteínas do Tecido Nervoso/genética , Receptores de N-Metil-D-Aspartato/genética , Adulto , Membrana Celular/genética , Membrana Celular/metabolismo , Criança , Feminino , Glicina/genética , Humanos , Deficiência Intelectual/patologia , Masculino , Mutação , Neurônios/metabolismo , Neurônios/patologia , Transporte Proteico/genética , Proteínas Recombinantes/genética
16.
Am J Med Genet A ; 173(1): 221-224, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27649277

RESUMO

Hand-Foot-Genital syndrome is a rare autosomal dominant condition characterized by distal limb anomalies and urogenital malformations. This disorder is associated with loss-of-function mutations in the HOXA13 gene. HOXA13 plays an important role in the development of distal limbs and lower genitourinary tract of the fetus. We report a novel familial 589 kb deletion in the 7p15.2 region identified in a male toddler and his mother. The proband had severe penoscrotal hypospadias, mild skeletal anomalies of the hands and feet, cardiac, renal, and gastrointestinal anomalies. His mother had a bicornuate uterus, cervical incompetence, and minor anomalies of her hands and feet. This family was found to have the smallest reported deletion of 7p15.2 to date, and presented with features typical of Hand-Foot-Genital syndrome in the mother, but much more severe phenotype in her son. This deletion included the entire HOXA cluster in addition to the SKAP2 and EVX1 genes. An RT-PCR analysis was performed to determine the expression of the HOXA genes in the proband and to explore a parent-of-origin effect. Our expression studies did not support the hypothesis of an imprinted status of the HOXA2, HOXA3, HOXA5, and HOXA11 genes in peripheral blood. To our knowledge, this is the first familial 7p15.2 deletion. This family raises possibility for sexual dimorphism as a mechanism for phenotypic variability in patients with the HOXA gene cluster deletions. © 2016 Wiley Periodicals, Inc.


Assuntos
Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Deformidades Congênitas do Pé/diagnóstico , Deformidades Congênitas do Pé/genética , Estudos de Associação Genética , Deformidades Congênitas da Mão/diagnóstico , Deformidades Congênitas da Mão/genética , Proteínas de Homeodomínio/genética , Fenótipo , Deleção de Sequência , Anormalidades Urogenitais/diagnóstico , Anormalidades Urogenitais/genética , Cromossomos Humanos Par 7 , Hibridização Genômica Comparativa , Humanos , Lactente , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Linhagem , Polimorfismo de Nucleotídeo Único
17.
Hum Genet ; 135(5): 569-86, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27071622

RESUMO

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal lung developmental disorder caused by heterozygous point mutations or genomic deletion copy-number variants (CNVs) of FOXF1 or its upstream enhancer involving fetal lung-expressed long noncoding RNA genes LINC01081 and LINC01082. Using custom-designed array comparative genomic hybridization, Sanger sequencing, whole exome sequencing (WES), and bioinformatic analyses, we studied 22 new unrelated families (20 postnatal and two prenatal) with clinically diagnosed ACDMPV. We describe novel deletion CNVs at the FOXF1 locus in 13 unrelated ACDMPV patients. Together with the previously reported cases, all 31 genomic deletions in 16q24.1, pathogenic for ACDMPV, for which parental origin was determined, arose de novo with 30 of them occurring on the maternally inherited chromosome 16, strongly implicating genomic imprinting of the FOXF1 locus in human lungs. Surprisingly, we have also identified four ACDMPV families with the pathogenic variants in the FOXF1 locus that arose on paternal chromosome 16. Interestingly, a combination of the severe cardiac defects, including hypoplastic left heart, and single umbilical artery were observed only in children with deletion CNVs involving FOXF1 and its upstream enhancer. Our data demonstrate that genomic imprinting at 16q24.1 plays an important role in variable ACDMPV manifestation likely through long-range regulation of FOXF1 expression, and may be also responsible for key phenotypic features of maternal uniparental disomy 16. Moreover, in one family, WES revealed a de novo missense variant in ESRP1, potentially implicating FGF signaling in the etiology of ACDMPV.


Assuntos
Genoma Humano , Impressão Genômica , Síndrome da Persistência do Padrão de Circulação Fetal/patologia , Alvéolos Pulmonares/anormalidades , Veias Pulmonares/patologia , Cromossomos Humanos Par 16/genética , Hibridização Genômica Comparativa , Feminino , Fatores de Transcrição Forkhead/genética , Genes Letais , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Recém-Nascido , Masculino , Linhagem , Síndrome da Persistência do Padrão de Circulação Fetal/genética , Alvéolos Pulmonares/patologia , Deleção de Sequência
18.
Hum Mol Genet ; 24(14): 4024-36, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25882708

RESUMO

Mutations in the gene for the latent transforming growth factor beta binding protein 4 (LTBP4) cause autosomal recessive cutis laxa type 1C. To understand the molecular disease mechanisms of this disease, we investigated the impact of LTBP4 loss on transforming growth factor beta (TGFß) signaling. Despite elevated extracellular TGFß activity, downstream signaling molecules of the TGFß pathway, including pSMAD2 and pERK, were down-regulated in LTBP4 mutant human dermal fibroblasts. In addition, TGFß receptors 1 and 2 (TGFBR1 and TGFBR2) were reduced at the protein but not at the ribonucleic acid level. Treatment with exogenous TGFß1 led to an initially rapid increase in SMAD2 phosphorylation followed by a sustained depression of phosphorylation and receptor abundance. In mutant cells TGFBR1 was co-localized with lysosomes. Treatment with a TGFBR1 kinase inhibitor, endocytosis inhibitors or a lysosome inhibitor, normalized the levels of TGFBR1 and TGFBR2. Co-immunoprecipitation demonstrated a molecular interaction between LTBP4 and TGFBR2. Knockdown of LTBP4 reduced TGFß receptor abundance and signaling in normal cells and supplementation of recombinant LTBP4 enhanced these measures in mutant cells. In a mouse model of Ltbp4 deficiency, reduced TGFß signaling and receptor levels were normalized upon TGFBR1 kinase inhibitor treatment. Our results show that LTBP4 interacts with TGFBR2 and stabilizes TGFß receptors by preventing their endocytosis and lysosomal degradation in a ligand-dependent and receptor kinase activity-dependent manner. These findings identify LTBP4 as a key molecule required for the stability of the TGFß receptor complex, and a new mechanism by which the extracellular matrix regulates cytokine receptor signaling.


Assuntos
Cútis Laxa/genética , Proteínas de Ligação a TGF-beta Latente/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Animais , Estudos de Casos e Controles , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo , Endocitose/genética , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Imunoprecipitação , Proteínas de Ligação a TGF-beta Latente/genética , Masculino , Camundongos , Camundongos Knockout , Mutação , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Transdução de Sinais , Proteína Smad2/genética , Proteína Smad2/metabolismo
19.
Am J Med Genet A ; 167A(9): 2188-96, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25914204

RESUMO

Ciliopathies such as cranioectodermal dysplasia, Sensenbrenner syndrome, short-rib polydactyly, and Jeune syndrome are associated with respiratory complications arising from rib cage dysplasia. While such ciliopathies have been demonstrated to involve primary cilia defects, we show motile cilia dysfunction in the airway of a patient diagnosed with cranioectodermal dysplasia. While this patient had mild thoracic dystrophy not requiring surgical treatment, there was nevertheless newborn respiratory distress, restrictive airway disease with possible obstructive airway involvement, repeated respiratory infections, and atelectasis. High-resolution videomicroscopy of nasal epithelial biopsy showed immotile/dyskinetic cilia and nasal nitric oxide was reduced, both of which are characteristics of primary ciliary dyskinesia, a sinopulmonary disease associated with mucociliary clearance defects due to motile cilia dysfunction in the airway. Exome sequencing analysis of this patient identified compound heterozygous mutations in WDR35, but no mutations in any of the 30 known primary ciliary dyskinesia genes or other cilia-related genes. Given that WDR35 is only known to be required for primary cilia function, we carried out WDR35 siRNA knockdown in human respiratory epithelia to assess the role of WDR35 in motile cilia function. This showed WDR35 deficiency disrupted ciliogenesis in the airway, indicating WDR35 is also required for formation of motile cilia. Together, these findings suggest patients with WDR35 mutations have an airway mucociliary clearance defect masked by their restrictive airway disease.


Assuntos
Osso e Ossos/anormalidades , Cílios/genética , Craniossinostoses/genética , Displasia Ectodérmica/genética , Doenças Respiratórias/genética , Criança , Heterozigoto , Humanos , Masculino , Mutação/genética , Proteínas/genética
20.
Am J Med Genet A ; 167A(8): 1921-6, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25866352

RESUMO

A 7-year-old female with developmental delay (DD), autism spectrum disorder (ASD), intellectual disability (ID), attention deficit hyperactivity disorder (ADHD), and seizures was referred to our laboratory for oligomicroarray analysis. The analysis revealed a 540 kb microdeletion in the chromosome 8q24.3 region (143,610,058-144,150,241) encompassing multiple genes. Two siblings of the proband were also analyzed. The proband's older sister with DD, seizures, and ASD has a 438 kb intragenic microdeletion of the GPHN gene in the chromosome 14q23.3 region (67,105,512-67,543,291) containing multiple exons, while the proband's older brother with DD, ASD, ID, and ADHD has both the 8q24.3 and the 14q23.3 deletions. All three siblings have a normal karyotype at the 650 G-band level of resolution. Parental FISH analysis indicates that the mother is a carrier for the 8q24.3 deletion and the father is a carrier for the 14q23.3 deletion. The 8q24.3 deletion seen in our patients has not been reported in the literature, while the small deletions of the 14q23.3 region involving multiple exons of the GPHN gene have been reported in a handful of patients in a recent study. The size of the 8q24.3 deletion and its genomic content, as well as the maternal family history, strongly suggest the association between the deletion and the neurodevelopmental disorders. Our study also provides more evidence in support of the association between GPHN deletion and neurodevelopmental disorders.


Assuntos
Cromossomos Humanos Par 14 , Cromossomos Humanos Par 8 , Variações do Número de Cópias de DNA , Impressão Genômica , Transtornos do Neurodesenvolvimento/genética , Criança , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Gravidez
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