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1.
Am J Hum Genet ; 108(2): 357-367, 2021 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-33508234

RESUMEN

Focal segmental glomerulosclerosis (FSGS) is the main pathology underlying steroid-resistant nephrotic syndrome (SRNS) and a leading cause of chronic kidney disease. Monogenic forms of pediatric SRNS are predominantly caused by recessive mutations, while the contribution of de novo variants (DNVs) to this trait is poorly understood. Using exome sequencing (ES) in a proband with FSGS/SRNS, developmental delay, and epilepsy, we discovered a nonsense DNV in TRIM8, which encodes the E3 ubiquitin ligase tripartite motif containing 8. To establish whether TRIM8 variants represent a cause of FSGS, we aggregated exome/genome-sequencing data for 2,501 pediatric FSGS/SRNS-affected individuals and 48,556 control subjects, detecting eight heterozygous TRIM8 truncating variants in affected subjects but none in control subjects (p = 3.28 × 10-11). In all six cases with available parental DNA, we demonstrated de novo inheritance (p = 2.21 × 10-15). Reverse phenotyping revealed neurodevelopmental disease in all eight families. We next analyzed ES from 9,067 individuals with epilepsy, yielding three additional families with truncating TRIM8 variants. Clinical review revealed FSGS in all. All TRIM8 variants cause protein truncation clustering within the last exon between residues 390 and 487 of the 551 amino acid protein, indicating a correlation between this syndrome and loss of the TRIM8 C-terminal region. Wild-type TRIM8 overexpressed in immortalized human podocytes and neuronal cells localized to nuclear bodies, while constructs harboring patient-specific variants mislocalized diffusely to the nucleoplasm. Co-localization studies demonstrated that Gemini and Cajal bodies frequently abut a TRIM8 nuclear body. Truncating TRIM8 DNVs cause a neuro-renal syndrome via aberrant TRIM8 localization, implicating nuclear bodies in FSGS and developmental brain disease.


Asunto(s)
Proteínas Portadoras/genética , Discapacidades del Desarrollo/genética , Epilepsia/genética , Glomeruloesclerosis Focal y Segmentaria/genética , Espacio Intranuclear/metabolismo , Síndrome Nefrótico/genética , Síndrome Nefrótico/metabolismo , Proteínas del Tejido Nervioso/genética , Adulto , Animales , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Línea Celular , Niño , Preescolar , Codón sin Sentido , Discapacidades del Desarrollo/metabolismo , Epilepsia/metabolismo , Femenino , Glomeruloesclerosis Focal y Segmentaria/metabolismo , Humanos , Riñón/metabolismo , Masculino , Ratones , Mutación , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/metabolismo , Fenotipo , Podocitos/metabolismo , Secuenciación del Exoma
2.
Genet Med ; 26(4): 101057, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38158856

RESUMEN

PURPOSE: We established the genetic etiology of a syndromic neurodevelopmental condition characterized by variable cognitive impairment, recognizable facial dysmorphism, and a constellation of extra-neurological manifestations. METHODS: We performed phenotypic characterization of 6 participants from 4 unrelated families presenting with a neurodevelopmental syndrome and used exome sequencing to investigate the underlying genetic cause. To probe relevance to the neurodevelopmental phenotype and craniofacial dysmorphism, we established two- and three-dimensional human stem cell-derived neural models and generated a stable cachd1 zebrafish mutant on a transgenic cartilage reporter line. RESULTS: Affected individuals showed mild cognitive impairment, dysmorphism featuring oculo-auriculo abnormalities, and developmental defects involving genitourinary and digestive tracts. Exome sequencing revealed biallelic putative loss-of-function variants in CACHD1 segregating with disease in all pedigrees. RNA sequencing in CACHD1-depleted neural progenitors revealed abnormal expression of genes with key roles in Wnt signaling, neurodevelopment, and organ morphogenesis. CACHD1 depletion in neural progenitors resulted in reduced percentages of post-mitotic neurons and enlargement of 3D neurospheres. Homozygous cachd1 mutant larvae showed mandibular patterning defects mimicking human facial dysmorphism. CONCLUSION: Our findings support the role of loss-of-function variants in CACHD1 as the cause of a rare neurodevelopmental syndrome with facial dysmorphism and multisystem abnormalities.


Asunto(s)
Anomalías Múltiples , Anomalías Craneofaciales , Anomalías Musculoesqueléticas , Trastornos del Neurodesarrollo , Animales , Humanos , Anomalías Múltiples/genética , Anomalías Craneofaciales/genética , Discapacidad Intelectual/genética , Anomalías Musculoesqueléticas/genética , Trastornos del Neurodesarrollo/genética , Fenotipo , Síndrome , Pez Cebra/genética
3.
Kidney Int ; 101(3): 473-484, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34780871

RESUMEN

Advances in clinical diagnostics and molecular tools have improved our understanding of the genetically heterogeneous causes underlying congenital anomalies of kidney and urinary tract (CAKUT). However, despite a sharp incline of CAKUT reports in the literature within the past 2 decades, there remains a plateau in the genetic diagnostic yield that is disproportionate to the accelerated ability to generate robust genome-wide data. Explanations for this observation include (i) diverse inheritance patterns with incomplete penetrance and variable expressivity, (ii) rarity of single-gene drivers such that large sample sizes are required to meet the burden of proof, and (iii) multigene interactions that might produce either intra- (e.g., copy number variants) or inter- (e.g., effects in trans) locus effects. These challenges present an opportunity for the community to implement innovative genetic and molecular avenues to explain the missing heritability and to better elucidate the mechanisms that underscore CAKUT. Here, we review recent multidisciplinary approaches at the intersection of genetics, genomics, in vivo modeling, and in vitro systems toward refining a blueprint for overcoming the diagnostic hurdles that are pervasive in urinary tract malformation cohorts. These approaches will not only benefit clinical management by reducing age at molecular diagnosis and prompting early evaluation for comorbid features but will also serve as a springboard for therapeutic development.


Asunto(s)
Sistema Urinario , Anomalías Urogenitales , Variaciones en el Número de Copia de ADN , Genómica , Humanos , Riñón/anomalías , Anomalías Urogenitales/diagnóstico , Anomalías Urogenitales/genética
4.
Hum Mol Genet ; 29(14): 2435-2450, 2020 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-32620954

RESUMEN

Dysfunction of the gonadotropin-releasing hormone (GnRH) axis causes a range of reproductive phenotypes resulting from defects in the specification, migration and/or function of GnRH neurons. To identify additional molecular components of this system, we initiated a systematic genetic interrogation of families with isolated GnRH deficiency (IGD). Here, we report 13 families (12 autosomal dominant and one autosomal recessive) with an anosmic form of IGD (Kallmann syndrome) with loss-of-function mutations in TCF12, a locus also known to cause syndromic and non-syndromic craniosynostosis. We show that loss of tcf12 in zebrafish larvae perturbs GnRH neuronal patterning with concomitant attenuation of the orthologous expression of tcf3a/b, encoding a binding partner of TCF12, and stub1, a gene that is both mutated in other syndromic forms of IGD and maps to a TCF12 affinity network. Finally, we report that restored STUB1 mRNA rescues loss of tcf12 in vivo. Our data extend the mutational landscape of IGD, highlight the genetic links between craniofacial patterning and GnRH dysfunction and begin to assemble the functional network that regulates the development of the GnRH axis.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Hormona Liberadora de Gonadotropina/genética , Síndrome de Kallmann/genética , Ubiquitina-Proteína Ligasas/genética , Proteínas de Pez Cebra/genética , Adulto , Anciano , Animales , Modelos Animales de Enfermedad , Femenino , Genes Dominantes/genética , Hormona Liberadora de Gonadotropina/deficiencia , Haploinsuficiencia/genética , Humanos , Síndrome de Kallmann/patología , Masculino , Persona de Mediana Edad , Mutación/genética , Neuronas/metabolismo , Neuronas/patología , Fenotipo , Pez Cebra/genética
5.
Am J Hum Genet ; 104(1): 94-111, 2019 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-30609410

RESUMEN

The use of whole-exome and whole-genome sequencing has been a catalyst for a genotype-first approach to diagnostics. Under this paradigm, we have implemented systematic sequencing of neonates and young children with a suspected genetic disorder. Here, we report on two families with recessive mutations in NCAPG2 and overlapping clinical phenotypes that include severe neurodevelopmental defects, failure to thrive, ocular abnormalities, and defects in urogenital and limb morphogenesis. NCAPG2 encodes a member of the condensin II complex, necessary for the condensation of chromosomes prior to cell division. Consistent with a causal role for NCAPG2, we found abnormal chromosome condensation, augmented anaphase chromatin-bridge formation, and micronuclei in daughter cells of proband skin fibroblasts. To test the functional relevance of the discovered variants, we generated an ncapg2 zebrafish model. Morphants displayed clinically relevant phenotypes, such as renal anomalies, microcephaly, and concomitant increases in apoptosis and altered mitotic progression. These could be rescued by wild-type but not mutant human NCAPG2 mRNA and were recapitulated in CRISPR-Cas9 F0 mutants. Finally, we noted that the individual with a complex urogenital defect also harbored a heterozygous NPHP1 deletion, a common contributor to nephronophthisis. To test whether sensitization at the NPHP1 locus might contribute to a more severe renal phenotype, we co-suppressed nphp1 and ncapg2, which resulted in significantly more dysplastic renal tubules in zebrafish larvae. Together, our data suggest that impaired function of NCAPG2 results in a severe condensinopathy, and they highlight the potential utility of examining candidate pathogenic lesions beyond the primary disease locus.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas de Unión al ADN/metabolismo , Complejos Multiproteicos/metabolismo , Mutación , Trastornos del Neurodesarrollo/genética , Trastornos del Neurodesarrollo/patología , Fenotipo , Anomalías Múltiples/genética , Anomalías Múltiples/patología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Niño , Preescolar , Proteínas del Citoesqueleto , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Proteínas de la Membrana/genética , Linaje , Síndrome , Pez Cebra/genética , Pez Cebra/crecimiento & desarrollo , Proteínas de Pez Cebra/genética
6.
Am J Med Genet A ; 188(2): 498-508, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34697879

RESUMEN

Autosomal recessive limb-girdle muscular dystrophy-1 (LGMDR1) is an autosomal recessive disorder characterized by progressive weakness of the proximal limb and girdle muscles. Biallelic mutations in CAPN3 are reported frequently to cause LGMDR1. Here, we describe 11 individuals from three unrelated consanguineous families that present with typical features of LGMDR1 that include proximal muscle wasting, weakness of the upper and lower limbs, and elevated serum creatine kinase. Whole-exome sequencing identified a rare homozygous CAPN3 variant near the exon 2 splice donor site that segregates with disease in all three families. mRNA splicing studies showed partial retention of intronic sequence and subsequent introduction of a premature stop codon (NM_000070.3: c.379 + 3A>G; p.Asp128Glyfs*15). Furthermore, we observe reduced CAPN3 expression in primary dermal fibroblasts derived from an affected individual, suggesting instability and/or nonsense-mediated decay of mutation-bearing mRNA. Genome-wide homozygosity mapping and single-nucleotide polymorphism analysis identified a shared haplotype and supports a possible founder effect for the CAPN3 variant. Together, our data extend the mutational spectrum of LGMDR1 and have implications for improved diagnostics for individuals of Pakistani origin.


Asunto(s)
Calpaína , Distrofia Muscular de Cinturas , Calpaína/genética , Humanos , Proteínas Musculares/genética , Distrofia Muscular de Cinturas/diagnóstico , Distrofia Muscular de Cinturas/genética , Mutación , Pakistán , ARN Mensajero/genética
7.
Hum Genet ; 140(12): 1733-1751, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34647195

RESUMEN

Mitochondrial disorders are collectively common, genetically heterogeneous disorders in both pediatric and adult populations. They are caused by molecular defects in oxidative phosphorylation, failure of essential bioenergetic supply to mitochondria, and apoptosis. Here, we present three affected individuals from a consanguineous family of Pakistani origin with variable seizures and intellectual disability. Both females display primary ovarian insufficiency (POI), while the male shows abnormal sex hormone levels. We performed whole exome sequencing and identified a recessive missense variant c.694C > T, p.Arg232Cys in TFAM that segregates with disease. TFAM (mitochondrial transcription factor A) is a component of the mitochondrial replisome machinery that maintains mtDNA transcription and replication. In primary dermal fibroblasts, we show depletion of mtDNA and significantly altered mitochondrial function and morphology. Moreover, we observed reduced nucleoid numbers with significant changes in nucleoid size or shape in fibroblasts from an affected individual compared to controls. We also investigated the effect of tfam impairment in zebrafish; homozygous tfam mutants carrying an in-frame c.141_149 deletion recapitulate the mtDNA depletion and ovarian dysgenesis phenotypes observed in affected humans. Together, our genetic and functional data confirm that TFAM plays a pivotal role in gonad development and expands the repertoire of mitochondrial disease phenotypes.


Asunto(s)
ADN Mitocondrial , Proteínas de Unión al ADN/genética , Genes Recesivos , Pérdida Auditiva/genética , Discapacidad Intelectual/genética , Proteínas Mitocondriales/genética , Insuficiencia Ovárica Primaria/genética , Convulsiones/genética , Factores de Transcripción/genética , Animales , Células Cultivadas , Femenino , Gónadas/embriología , Humanos , Masculino , Linaje , Pez Cebra/genética
8.
Am J Hum Genet ; 101(5): 789-802, 2017 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-29100090

RESUMEN

Renal agenesis and hypodysplasia (RHD) are major causes of pediatric chronic kidney disease and are highly genetically heterogeneous. We conducted whole-exome sequencing in 202 case subjects with RHD and identified diagnostic mutations in genes known to be associated with RHD in 7/202 case subjects. In an additional affected individual with RHD and a congenital heart defect, we found a homozygous loss-of-function (LOF) variant in SLIT3, recapitulating phenotypes reported with Slit3 inactivation in the mouse. To identify genes associated with RHD, we performed an exome-wide association study with 195 unresolved case subjects and 6,905 control subjects. The top signal resided in GREB1L, a gene implicated previously in Hoxb1 and Shha signaling in zebrafish. The significance of the association, which was p = 2.0 × 10-5 for novel LOF, increased to p = 4.1 × 10-6 for LOF and deleterious missense variants combined, and augmented further after accounting for segregation and de novo inheritance of rare variants (joint p = 2.3 × 10-7). Finally, CRISPR/Cas9 disruption or knockdown of greb1l in zebrafish caused specific pronephric defects, which were rescued by wild-type human GREB1L mRNA, but not mRNA containing alleles identified in case subjects. Together, our study provides insight into the genetic landscape of kidney malformations in humans, presents multiple candidates, and identifies SLIT3 and GREB1L as genes implicated in the pathogenesis of RHD.


Asunto(s)
Anomalías Congénitas/genética , Exoma/genética , Enfermedades Renales/congénito , Riñón/anomalías , Mutación/genética , Proteínas de Neoplasias/genética , Alelos , Animales , Estudios de Casos y Controles , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Femenino , Heterogeneidad Genética , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Herencia/genética , Homocigoto , Humanos , Enfermedades Renales/genética , Masculino , Proteínas de la Membrana/genética , Ratones , Fenotipo , ARN Largo no Codificante/genética , Sistema Urinario/anomalías , Anomalías Urogenitales/genética , Pez Cebra
9.
Am J Hum Genet ; 100(2): 352-363, 2017 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-28132691

RESUMEN

Degradation of proteins by the ubiquitin-proteasome system (UPS) is an essential biological process in the development of eukaryotic organisms. Dysregulation of this mechanism leads to numerous human neurodegenerative or neurodevelopmental disorders. Through a multi-center collaboration, we identified six de novo genomic deletions and four de novo point mutations involving PSMD12, encoding the non-ATPase subunit PSMD12 (aka RPN5) of the 19S regulator of 26S proteasome complex, in unrelated individuals with intellectual disability, congenital malformations, ophthalmologic anomalies, feeding difficulties, deafness, and subtle dysmorphic facial features. We observed reduced PSMD12 levels and an accumulation of ubiquitinated proteins without any impairment of proteasome catalytic activity. Our PSMD12 loss-of-function zebrafish CRISPR/Cas9 model exhibited microcephaly, decreased convolution of the renal tubules, and abnormal craniofacial morphology. Our data support the biological importance of PSMD12 as a scaffolding subunit in proteasome function during development and neurogenesis in particular; they enable the definition of a neurodevelopmental disorder due to PSMD12 variants, expanding the phenotypic spectrum of UPS-dependent disorders.


Asunto(s)
Trastornos del Neurodesarrollo/genética , Complejo de la Endopetidasa Proteasomal/genética , Adolescente , Animales , Niño , Preescolar , Variaciones en el Número de Copia de ADN , Modelos Animales de Enfermedad , Regulación hacia Abajo , Femenino , Eliminación de Gen , Humanos , Lactante , Discapacidad Intelectual/genética , Masculino , Microcefalia/genética , Polimorfismo de Nucleótido Simple , Pez Cebra/genética
10.
Genet Med ; 21(11): 2532-2542, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31036918

RESUMEN

PURPOSE: The purpose of this study was to expand the genetic architecture of neurodevelopmental disorders, and to characterize the clinical features of a novel cohort of affected individuals with variants in ZNF142, a C2H2 domain-containing transcription factor. METHODS: Four independent research centers used exome sequencing to elucidate the genetic basis of neurodevelopmental phenotypes in four unrelated families. Following bioinformatic filtering, query of control data sets, and secondary variant confirmation, we aggregated findings using an online data sharing platform. We performed in-depth clinical phenotyping in all affected individuals. RESULTS: We identified seven affected females in four pedigrees with likely pathogenic variants in ZNF142 that segregate with recessive disease. Affected cases in three families harbor either nonsense or frameshifting likely pathogenic variants predicted to undergo nonsense mediated decay. One additional trio bears ultrarare missense variants in conserved regions of ZNF142 that are predicted to be damaging to protein function. We performed clinical comparisons across our cohort and noted consistent presence of intellectual disability and speech impairment, with variable manifestation of seizures, tremor, and dystonia. CONCLUSION: Our aggregate data support a role for ZNF142 in nervous system development and add to the emergent list of zinc finger proteins that contribute to neurocognitive disorders.


Asunto(s)
Discapacidades del Desarrollo/genética , Trastornos del Neurodesarrollo/genética , Transactivadores/genética , Adolescente , Adulto , Niño , Estudios de Cohortes , Biología Computacional/métodos , Distonía/genética , Familia , Femenino , Humanos , Discapacidad Intelectual/genética , Mutación , Mutación Missense , Linaje , Fenotipo , Convulsiones/genética , Trastornos del Habla/genética , Transactivadores/metabolismo , Secuenciación del Exoma
11.
Hum Genomics ; 12(1): 11, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29490693

RESUMEN

BACKGROUND: Intellectual disability (ID) is a common condition with a population prevalence frequency of 1-3% and an enrichment for males, driven in part by the contribution of mutant alleles on the X-chromosome. Among the more than 500 genes associated with ID, DDX3X represents an outlier in sex specificity. Nearly all reported pathogenic variants of DDX3X are de novo, affect mostly females, and appear to be loss of function variants, consistent with the hypothesis that haploinsufficiency at this locus on the X-chromosome is likely to be lethal in males. RESULTS: We evaluated two male siblings with syndromic features characterized by mild-to-moderate ID and progressive spasticity. Quad-based whole-exome sequencing revealed a maternally inherited missense variant encoding p.R79K in DDX3X in both siblings and no other apparent pathogenic variants. We assessed its possible relevance to their phenotype using an established functional assay for DDX3X activity in zebrafish embryos and found that this allele causes a partial loss of DDX3X function and thus represents a hypomorphic variant. CONCLUSIONS: Our genetic and functional data suggest that partial loss of function of DDX3X can cause syndromic ID. The p.R79K allele affects a region of the protein outside the critical RNA helicase domain, offering a credible explanation for the observed retention of partial function, viability in hemizygous males, and lack of pathology in females. These findings expand the gender spectrum of pathology of this locus and suggest that analysis for DDX3X variants should be considered relevant for both males and females.


Asunto(s)
ARN Helicasas DEAD-box/genética , Discapacidad Intelectual/genética , Enfermedades Neurodegenerativas/genética , Trastornos del Neurodesarrollo/genética , Adolescente , Adulto , Alelos , Cromosomas Humanos X/genética , Exoma/genética , Femenino , Humanos , Discapacidad Intelectual/fisiopatología , Masculino , Mutación , Enfermedades Neurodegenerativas/fisiopatología , Trastornos del Neurodesarrollo/fisiopatología , Linaje , Secuenciación del Exoma , Adulto Joven
12.
J Am Soc Nephrol ; 29(8): 2110-2122, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30002222

RESUMEN

BACKGROUND: We previously reported that mutations in the anillin (ANLN) gene cause familial forms of FSGS. ANLN is an F-actin binding protein that modulates podocyte cell motility and interacts with the phosphoinositide 3-kinase (PI3K) pathway through the slit diaphragm adaptor protein CD2-associated protein (CD2AP). However, it is unclear how the ANLN mutations cause the FSGS phenotype. We hypothesized that the R431C mutation exerts its pathogenic effects by uncoupling ANLN from CD2AP. METHODS: We conducted in vivo complementation assays in zebrafish to determine the effect of the previously identified missense ANLN variants, ANLNR431C and ANLNG618C during development. We also performed in vitro functional assays using human podocyte cell lines stably expressing wild-type ANLN (ANLNWT ) or ANLNR431C . RESULTS: Experiments in anln-deficient zebrafish embryos showed a loss-of-function effect for each ANLN variant. In human podocyte lines, expression of ANLNR431C increased cell migration, proliferation, and apoptosis. Biochemical characterization of ANLNR431C -expressing podocytes revealed hyperactivation of the PI3K/AKT/mTOR/p70S6K/Rac1 signaling axis and activation of mTOR-driven endoplasmic reticulum stress in ANLNR431C -expressing podocytes. Inhibition of mTOR, GSK-3ß, Rac1, or calcineurin ameliorated the effects of ANLNR431C . Additionally, inhibition of the calcineurin/NFAT pathway reduced the expression of endogenous ANLN and mTOR. CONCLUSIONS: The ANLNR431C mutation causes multiple derangements in podocyte function through hyperactivation of PI3K/AKT/mTOR/p70S6K/Rac1 signaling. Our findings suggest that the benefits of calcineurin inhibition in FSGS may be due, in part, to the suppression of ANLN and mTOR. Moreover, these studies illustrate that rational therapeutic targets for familial FSGS can be identified through biochemical characterization of dysregulated podocyte phenotypes.


Asunto(s)
Glomeruloesclerosis Focal y Segmentaria/genética , Proteínas de Microfilamentos/genética , Fosfatidilinositol 3-Quinasas/genética , Proteínas Proto-Oncogénicas c-akt/genética , Serina-Treonina Quinasas TOR/metabolismo , Animales , Apoptosis/genética , Movimiento Celular/genética , Células Cultivadas , Regulación de la Expresión Génica , Glomeruloesclerosis Focal y Segmentaria/patología , Glomeruloesclerosis Focal y Segmentaria/fisiopatología , Humanos , Mutación Missense , Podocitos/metabolismo , Sensibilidad y Especificidad , Transducción de Señal , Pez Cebra , Proteína de Unión al GTP rac1/genética
13.
Ann Neurol ; 82(4): 562-577, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28892560

RESUMEN

OBJECTIVE: Autosomal recessive primary microcephaly (MCPH) is a rare condition characterized by a reduced cerebral cortex accompanied with intellectual disability. Mutations in 17 genes have been shown to cause this phenotype. Recently, mutations in CIT, encoding CRIK (citron rho-interacting kinase)-a component of the central spindle matrix-were added. We aimed at identifying novel MCPH-associated genes and exploring their functional role in pathogenesis. METHODS: Linkage analysis and whole exome sequencing were performed in consanguineous and nonconsanguineous MCPH families to identify disease-causing variants. Functional consequences were investigated by RNA studies and on the cellular level using immunofluorescence and microscopy. RESULTS: We identified homozygous mutations in KIF14 (NM_014875.2;c.263T>A;pLeu88*, c.2480_2482delTTG; p.Val827del, and c.4071G>A;p.Gln1357=) as the likely cause in 3 MCPH families. Furthermore, in a patient presenting with a severe form of primary microcephaly and short stature, we identified compound heterozygous missense mutations in KIF14 (NM_014875.2;c.2545C>G;p.His849Asp and c.3662G>T;p.Gly1221Val). Three of the 5 identified mutations impaired splicing, and 2 resulted in a truncated protein. Intriguingly, Kif14 knockout mice also showed primary microcephaly. Human kinesin-like protein KIF14, a microtubule motor protein, localizes at the midbody to finalize cytokinesis by interacting with CRIK. We found impaired localization of both KIF14 and CRIK at the midbody in patient-derived fibroblasts. Furthermore, we observed a large number of binucleated and apoptotic cells-signs of failed cytokinesis that we also observed in experimentally KIF14-depleted cells. INTERPRETATION: Our data corroborate the role of an impaired cytokinesis in the etiology of primary and syndromic microcephaly, as has been proposed by recent findings on CIT mutations. Ann Neurol 2017;82:562-577.


Asunto(s)
Citocinesis/genética , Regulación de la Expresión Génica/genética , Cinesinas/genética , Microcefalia/genética , Mutación/genética , Proteínas Oncogénicas/genética , Caspasa 7/metabolismo , Movimiento Celular/genética , Células Cultivadas , Niño , Preescolar , Salud de la Familia , Femenino , Fibroblastos/fisiología , Estudio de Asociación del Genoma Completo , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Masculino , Microcefalia/diagnóstico por imagen , Microcefalia/patología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Tubulina (Proteína)/metabolismo
16.
PLoS One ; 19(2): e0296921, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38359051

RESUMEN

The decreasing status of on IUCN of Koklass pheasant (Pucrasia macrolopha) belongs to the family Phasianidae and the order Galliform needs the attention of researchers. The species with habitats as low as 6,000 feet and as high as 11,000 feet certainly cover a broad variety of habitats, such a wide altitude range embraces a diverse range of habitats. Insufficient research has been conducted on the suitability of moist temperate forests as a potential habitat for the Koklass pheasant. Therefore, this study was carried out to explore habitat suitability in 15 different sites which were located in the 4 districts of Hazara Division using GIS data science and environmental variables. A random sampling technique was used for laying out the transect. Overall, 45 line transects (Length 2-4 km, Width 10-30 m) were laid out in study sites. The size of sample plots for trees was 10x10m, for shrubs (4 x4m), and herbs and grasses 1x1m. The other habitat parameters like elevation, slope, cover, and frequency of plant at each point were also considered. We found the uneven distribution of Koklass pheasant in the Hazara Division. There were 59 occurrence points identified and highlighted the distribution of Koklass pheasant in the study area. Although all environmental variables were preferred by Koklass pheasant in its habitat statistical analysis proved that slope, level of disturbance, tree and shrub frequency of habitat contributed mostly to the presence of Koklass in each study site except the contribution of soil and herbs. The potential suitable habitat of Koklass pheasant was estimated to be 439.6 km2 areas starting from Abbottabad to Mansehra in the Hazara division. Awareness and enforcing legal protection are recommended for the conservation of Koklass Pheasant in Moist temperate forest.


Asunto(s)
Ecosistema , Bosques , Animales , Codorniz , Árboles , Altitud
17.
Endocrinology ; 165(10)2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39254333

RESUMEN

There has been an alarming trend toward earlier puberty in girls, suggesting the influence of an environmental factor(s). As the reactivation of the reproductive axis during puberty is thought to be mediated by the hypothalamic neuropeptides kisspeptin and gonadotropin-releasing hormone (GnRH), we asked whether an environmental compound might activate the kisspeptin (KISS1R) or GnRH receptor (GnRHR). We used GnRHR or KISS1R-expressing HEK293 cells to screen the Tox21 10K compound library, a compendium of pharmaceuticals and environmental compounds, for GnRHR and KISS1R activation. Agonists were identified using Ca2+ flux and phosphorylated extracellularly regulated kinase (p-ERK) detection assays. Follow-up studies included measurement of genes known to be upregulated upon receptor activation using relevant murine or human cell lines and molecular docking simulation. Musk ambrette was identified as a KISS1R agonist, and treatment with musk ambrette led to increased expression of Gnrh1 in murine and human hypothalamic cells and expansion of GnRH neuronal area in developing zebrafish larvae. Molecular docking demonstrated that musk ambrette interacts with the His309, Gln122, and Gln123 residues of the KISS1R. A group of cholinergic agonists with structures similar to methacholine was identified as GnRHR agonists. When applied to murine gonadotrope cells, these agonists upregulated Fos, Jun, and/or Egr1. Molecular docking revealed a potential interaction between GnRHR and 5 agonists, with Asn305 constituting the most conservative GnRHR binding site. In summary, using a Tox21 10K compound library screen combined with cellular, molecular, and structural biology techniques, we have identified novel environmental agents that may activate the human KISS1R or GnRHR.


Asunto(s)
Receptores de Kisspeptina-1 , Receptores LHRH , Humanos , Femenino , Animales , Receptores de Kisspeptina-1/metabolismo , Receptores de Kisspeptina-1/genética , Receptores LHRH/metabolismo , Receptores LHRH/genética , Ratones , Células HEK293 , Pez Cebra , Hormona Liberadora de Gonadotropina/metabolismo , Pubertad/efectos de los fármacos , Hipotálamo/metabolismo , Hipotálamo/efectos de los fármacos , Simulación del Acoplamiento Molecular , Maduración Sexual/efectos de los fármacos , Maduración Sexual/fisiología , Kisspeptinas/metabolismo , Kisspeptinas/genética , Contaminantes Ambientales/toxicidad , Contaminantes Ambientales/farmacología
18.
Insects ; 13(2)2022 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-35206762

RESUMEN

Bees play a very important role in pollination, especially western honey bees, which contribute upwards of billions of dollars concerning crop pollination. Hairiness plays an important role in pollination success by transporting pollen, and pollen intake, but there is a lack of detailed studies on the morphological mechanisms. The hairiness trait is barely discussed in pollinator trait analysis because of the lack of systematic techniques used to measure hairiness. This paper reports a novel method that is used to measure the hair length of different body parts of a western honey bee through a stereomicroscope equipped with live measurement module software. Scanning electron microscope (SEM) was used to update the knowledge regarding the hair structure of a western honey bee. We explained different types of hairs, hair branches, and their distributions on different body parts, which are discussed in detail. A positive correlation was found between hair length and the number of branches on all body parts. Five types of branches were observed, and these branches vary with different body parts. Our study provides sufficient details about the hair morphology of the western honey bee and a new methodology for measuring hair length. This methodology will improve the knowledge about understanding the pollination efficiency of the western honey bee.

19.
PLoS One ; 16(1): e0245279, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33450743

RESUMEN

Northern red muntjac (Muntiacus vaginalis; "barking deer") is a shy and small-sized cervid mammal, limited to the outer Himalayan foothill forests in Pakistan. Habitat characteristics were measured by locating direct and indirect signs. To quantify habitat utilization of barking deer, 80 field surveys were conducted in the study area along transects. 1200 Quadrats at 50 m intervals were deployed along these transect lines to determine microhabitat factors associated with seasonal distribution. The food composition of the barking deer was determined through fecal droppings analysis by micro-histological technique. Forty-five fecal samples of barking deer were collected from the study area (Murree-Kotli Sattian-Kahuta National Pak); summer (28) and winter (17). The micro-histological analysis revealed that more plant species are available in its habitat during the summer season (27) as compared to winter (19). Due to browsing nature barking deer mostly feed on trees in both seasons. While shrubs are slightly higher in winters. In summer barking deer consumed 10 Trees, 6 Shrubs, 5 Herbs, and 6 kinds of grass species. Dominant tree species were Phyllanthus emblica and Acacia modesta. Dominant shrub species were Ziziphus nummularia and Justicia adhatoda. In winter barking deer consumed 8 Trees, 7 Shrubs, 3 Herbs, and 1 Grass. Dominant tree species were Bauhinia variegata and Acacia modesta while shrubs included Ziziphus nummularia and Carissa opaca.


Asunto(s)
Alimentación Animal/análisis , Ecosistema , Animales , Dieta/veterinaria , Heces/química , Ciervo Muntjac , Pakistán , Estaciones del Año
20.
Eur J Med Genet ; 64(7): 104226, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33872773

RESUMEN

Different mutations in the Growth/Differentiation Factor 5 gene (GDF5) have been associated with varying types of skeletal dysplasia, including Grebe type chondrodysplasia (GTC), Hunter-Thompson syndrome, Du Pan Syndrome and Brachydactyly type C (BDC). Heterozygous pathogenic mutations exert milder effects, whereas homozygous mutations are known to manifest more severe phenotypes. In this study, we report a GDF5 frameshift mutation (c.404delC) segregating over six generations in an extended consanguineous Pakistani family. The family confirmed that both GTC and BDC are part of the GDF5 mutational spectrum, with severe GTC associated with homozygosity, and with a wide phenotypic variability among heterozygous carriers, ranging from unaffected non-penetrant carriers, to classical BDC and to novel unclassified types of brachydactylies.


Asunto(s)
Braquidactilia/genética , Factor 5 de Diferenciación de Crecimiento/genética , Anomalías Musculoesqueléticas/genética , Osteocondrodisplasias/genética , Braquidactilia/patología , Femenino , Mutación del Sistema de Lectura , Heterocigoto , Homocigoto , Humanos , Masculino , Anomalías Musculoesqueléticas/patología , Osteocondrodisplasias/patología , Linaje
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