Analysis of IQSEC2 gene variant in a child with X-linked mental retardation / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical phenotype and genetic variants of a child with X-linked mental retardation caused by IQSEC2 gene mutation, and provide reference for the diagnosis of the disease.@*METHODS@#The child was subjected to next generation sequencing (NGS), and the diagnosis was made by taking consideration of her clinical characteristics.@*RESULTS@#The child has presented with global developmental delay, particularly in fine motor skill and language development, in addition with intellectual disability. Genetic testing revealed that she has harbored a heterozygous c.1861dup variant of the IQSEC2 gene, which was not detected in either parent.@*CONCLUSION@#The de novo c.186ldup variant of the IQSEC2 gene probably underlay the X-linked mental retardation in this child. Above finding has, expanded the spectrum of IQSEC2 gene mutations and provide a basis for the diagnosis of similar cases.

PREX2 gene's expression in gastric antral epithelial cells of patients with H. pylori infection / Expressão do gene PREX2 em células epiteliais antrais gástricas em pacientes com infecção por H. pylori

ABSTRACT BACKGROUND: The Prex2 protein is a member of the Rac family proteins that belongs to small G proteins with a critical role in cell migration, cell proliferation, and apoptosis through its effects on PI3K cell signaling pathway and phosphatase activity of PTEN protein. The effect of PREX2 gene expression has been shown in some cancer cells. A survey of PREX2 gene expression in gastric antral epithelial cells of gastric cancer patients with Helicobacter pylori various genotypes infection can conduct to better understanding H. pylori infection's carcinogenesis. METHODS: In a case-control study, PREX2 gene expression was evaluated in gastric antral biopsy samples on four groups of patients referred to Sanandaj hospitals, including gastritis with (n=23) and without (n=27) H. pylori infection and gastric cancer with (n=21) and without (n=32) H. pylori infection. Each gastric biopsy sample's total RNA was extracted and cDNA synthesized by using Kits (Takara Company). The PREX2 gene expression was measured using the relative quantitative real-time RT-PCR method and ΔΔCt formula. RESULTS: The PREX2 gene expression increased in gastric antral biopsy samples of gastritis and gastric cancer patients with H. pylori infection (case groups) than patients without H. pylori infection (control groups) 2.38 and 2.27 times, respectively. The patients with H. pylori vacA s1m1 and sabB genotypes infection showed a significant increase of PREX2 gene expression in gastric cancer antral epithelial cells. CONCLUSION: H. pylori vacA s1m1 and sabB genotypes have the positive correlations with PREX2 gene expression in gastric antral epithelial cells of gastritis and gastric cancer patients.

RESUMO CONTEXTO: A proteína Prex2 é membro das proteínas da família Rac que pertencem a pequenas proteínas G com um papel crítico na migração celular, na proliferação celular e na apoptose através de seus efeitos na via de sinalização celular PI3K e atividade fosfatase da proteína PTEN. O efeito da expressão genética PREX2 tem sido mostrada em algumas células cancerosas. Um levantamento da expressão genética PREX2 em células epiteliais antrais gástricas de pacientes infectados com vários genótipos de Helicobacter pylori pode conduzir a um melhor entendimento da carcinogênese da infecção por H. pylori. MÉTODOS: Em estudo de caso-controle, a expressão genética PREX2 foi avaliada em amostras de biópsia antral gástrica em quatro grupos de pacientes encaminhados aos hospitais de Sanandaj, incluindo gastrite com (n=23) e sem (n=27) infecção por H. pylori e de câncer gástrico com (n=21) e sem (n=32) infecção por H. pylori. O RNA total de cada amostra de biópsia gástrica foi extraído e cDNA sintetizado por meio de kits (Takara Company). A expressão genética PREX2 foi medida utilizando-se o método RT-PCR em tempo real quantitativo relativo e a fórmula ΔΔCt. RESULTADOS: A expressão genética PREX2 aumentou em amostras de biópsia antral gástrica de pacientes com gastrite e câncer gástrico com infecção por H. pylori (grupos de casos) em relação aos sem infecção por H. pylori (grupos de controle) 2,38 e 2,27 vezes, respectivamente. Os pacientes com infecção por genótipos H. pylori vacA s1m1 e sabB apresentaram um aumento significativo da expressão genética PREX2 em células epiteliais antrais de câncer gástrico. CONCLUSÃO: Os genótipos H. pylori vacA s1m1 e sabB têm correlações positivas com a expressão genética PREX2 em células epiteliais antrais gástricas de pacientes com câncer gástrico e gastrites.

Analysis of FGD1 gene variant in a child with Aarskog-Scott syndrome / 中华医学遗传学杂志

OBJECTIVE@#To detect pathogenic variant of the FGD1 gene in a boy with Aarskog-Scott syndrome.@*METHODS@#Genetic variant was detected by high-throughput sequencing. Suspected variant was verified by Sanger sequencing. The nature and impact of the candidate variant were predicted by bioinformatic analysis.@*RESULTS@#The child was found to harbor a novel c.1906C>T hemizygous variant of the FGD1 gene, which has led to conversion of Arginine to Tryptophane at codon 636(p.Arg636Trp). The same variant was found in his mother but not father. Based on the American College of Medical Genetics and Genomics guidelines, the c.1906C>T variant of FGD1 gene was predicted to be likely pathogenic(PM1+PM2+PM5+PP2+PP3+PP4).@*CONCLUSION@#The novel c.1906C>T variant of the FGD1 gene may underlay the Aarskog-Scott syndrome in this child. Above finding has enabled diagnosis for the boy.

Análise da relação da ocorrência de polimorfismo de nucleotídeo único do gene DOCK9 em ceratocone / Relation analysis of the occurrence of single nucleotide polymorphism of the DOCK9 gene in keratoconus

RESUMO Objetivo: Avaliar a ocorrência de mutação em locus gênico candidato e sua relação com ceratocone em pacientes atendidos no Brasil comparados a voluntários saudáveis, através da análise de polimorfismo de nucleotídeo único no gene DOCK9. Métodos: Neste estudo clínico foram avaliados 108 indivíduos, sendo 46 pacientes com ceratocone e 62 voluntários saudáveis (controles). Amostras de DNA foram obtidas do sangue coletado de pacientes com ceratocone e controles para a realização de análise de genotipagem. O genótipo do polimorfismo de nucleotídeo único rs7995432 no gene DOCK9 foi determinado através de reação em cadeia da polimerase em tempo real (qPCR). Resultados: A frequência do alelo mutante (C) foi de 4,8% para os pacientes e 7,6% para os controles. Para o alelo selvagem (T), as frequências foram de 95,2% para os pacientes e 92,4% para os controles. O genótipo heterozigótico esteve presente em 9,5% dos pacientes e 11% dos controles, enquanto o genótipo homozigótico para o alelo selvagem (TT) foi encontrado em 90,5% e 87% para os pacientes e controles, respectivamente. Conclusão: Não foram observadas diferenças significativas na frequência e discriminação dos alelos mutante e selvagem entre os pacientes com ceratocone e os controles. Portanto, não foi possível fazer uma associação destas mutações no gene DOCK9 com a ocorrência do ceratocone para esta população.

ABSTRACT Objective: To evaluate the occurrence of a mutation in candidate genetic loci and its relation with keratoconus in patients treated in Brazil compared to healthy volunteers, through analysis of single nucleotide polymorphism in the DOCK9 gene. Methods: In this clinical study, 108 participants were evaluated, including 46 keratoconus patients and 62 healthy volunteers (controls). DNA samples were extracted from collected blood from keratoconus patients and controls. The genotyping of the single nucleotide polymorphism rs7995432 in the DOCK9 gene was determined through a real-time polymerase chain reaction (qPCR). Results: The frequency of the mutant allele (C) was 4.8% in patients and 7.6% in controls. For the wild allele (T), the frequencies were 95.2% in patients and 92.4% in controls. The heterozygous genotype was present in 9.5% of patients and 11% of controls, while the homozygous genotype for the wild allele (TT) was found in 90.5% and 87% for patients and controls, respectively. Conclusion: There were no significant differences un the frequency and discrimination of the mutant and wild alleles between patients and controls. Therefore, these results confirm no association of these mutations in the DOCK9 gene and the occurrence of keratoconus for this population.

Inmunodeficiencia combinada con compromiso cutáneo asociada a mutación en DOCK8 / Combined immunodeficiency with cutaneous manifestations associated with DOCK8 mutation

Diferentes inmunodeficiencias primarias se caracterizan por niveles elevados de IgE e infecciones cutáneas de origen viral. Describimos el caso de un niño de 2 años y 8 meses de edad, con inmunodeficiencia combinada, dermatitis y molusco contagioso diseminado. El paciente presentaba niveles aumentados de IgE, eosinofilia y marcada linfopenia a predominio de TCD8. Se encontraron alteraciones en los ensayos funcionales por cultivo y en la respuesta a la vacunación. Resultados normales de la proteína ZAP-70, funcionalidad NK y niveles de HLA I, tendientes a verificar alteraciones cuantitativas y funcionales de las células citotóxicas, llevaron a la sospecha de deficiencia en el gen DOCK8. El resultado positivo del estudio molecular, junto con las características clínicas e inmunológicas del paciente, confirmaron el diagnóstico de esta nueva inmunodeficiencia, que, de acuerdo con nuestro conocimiento, sería el primer caso diagnosticado en un hospital pediátrico en nuestro país.

Different primary immunodeficiencies present increased levels of IgE and cutaneous infections of viral etiology. We report a case of a 2 y, 8 m old boy with combined immunodeficiency, dermatitis and disseminated molluscum contagiosum. The patient presented high titers of IgE, eosinophilia and pronounced TCD8 lymphopenia. Impaired proliferation assays and abnormal antibody response to vaccination were found. Normal results of ZAP-70 protein, NK function, and HLA I levels, to test quantitatives and functional defects of cytotoxic cells, lead us to suspect a mutation in DOCK8 gene. Positive result in molecular study together with clinical and immunology features in the patient confirmed the diagnosis of this new immunodeficiency, being to the authors ́ knowledge the first case recorded in a paediatric hospital in our country.

Increased p190RhoGEF expression in activated B cells correlates with the induction of the plasma cell differentiation

Previously, we demonstrated that the p190 Rho guanine nucleotide exchange factor (p190RhoGEF) was induced following CD40 stimulation of B cells. In this study, we examined whether p190RhoGEF and a downstream effector molecule RhoA are required for B cell differentiation. Expression of p190RhoGEF positively correlated with the expression of surface markers and transcriptional regulators that are characteristic of mature B cells with plasma cell (PC) phenotypes. Moreover, either the overexpression of p190RhoGEF or the expression of a constitutively active RhoA drove cellular differentiation toward PC phenotypes. B cell maturation was abrogated in cells that overexpressed p190RhoGEF and a dominant-negative form of RhoA simultaneously. CD40-mediated maturation events were also abrogated in cells that overexpressed either dominant-negative p190RhoGEF or RhoA. Together, these data provide evidence that p190RhoGEF signaling through RhoA in CD40-activated B cells drives the induction of the PC differentiation.

Inhibition of cytohesin-1 by siRNA leads to reduced IGFR signaling in prostate cancer

To explore how cytohesin-1 (CYTH-1) small interfering RNA (siRNA) influences the insulin-like growth factor receptor (IGFR)-associated signal transduction in prostate cancer, we transfected human prostate cancer PC-3 cell lines with liposome-encapsulatedCYTH-1 siRNA in serum-free medium and exposed the cells to 100 nM IGF-1. The mRNA and protein levels of the signal molecules involved in the IGFR signaling pathways were determined by real-time PCR and detected by Western blotting. The relative mRNA levels of CYTH-1, c-Myc, cyclinD1 and IGF-1R (CYTH-1 siRNA group vs scrambled siRNA group) were 0.26 vs 0.97, 0.34 vs 1.06, 0.10 vs 0.95, and 0.27 vs 0.41 (P < 0.05 for all), respectively. The relative protein levels of CYTH-1, pIGF-1R, pIRS1, pAkt1, pErk1, c-Myc, and cyclinD1 (CYTH-1 siRNA group vsscrambled siRNA group) were 0.10 vs 1.00 (30 min), 0.10 vs 0.98 (30 min), 0.04 vs 0.50 (30 min), 0.10 vs 1.00 (30 min), 0.10 vs 1.00 (30 min), 0.13 vs 0.85 (5 h), and 0.08 vs 0.80 (7 h), respectively. The tyrosine kinase activity of IGF-1R was associated with CYTH-1. The proliferative activity of PC-3 cells transfected with CYTH-1 siRNA was significantly lower than that of cells transfected with scrambled siRNA at 48 h (40.5 vs87.6 percent, P < 0.05) and at 72 h (34.5 vs 93.5 percent, P < 0.05). In conclusion, the interference of siRNA with cytohesin-1 leads to reduced IGFR signaling in prostate cancer; therefore, CYTH-1 might serve as a new molecular target for the treatment of prostate cancer.

Involvement of betaPIX in angiotensin II-induced migration of vascular smooth muscle cells

Angiotensin II (Ang II) stimulates migration of vascular smooth muscle cell (VSMC) in addition to its contribution to contraction and hypertrophy. It is well established that Rho GTPases regulate cellular contractility and migration by reorganizing the actin cytoskeleton. Ang II activates Rac1 GTPase, but its upstream guanine nucleotide exchange factor (GEF) remains elusive. Here, we show that Ang II-induced VSMC migration occurs in a betaPIX GEF-dependent manner. betaPIX-specific siRNA treatment significantly inhibited Ang II-induced VSMC migration. Ang II activated the catalytic activity of betaPIX towards Rac1 in dose- and time-dependent manners. Activity reached a peak at 10 min and declined close to a basal level by 30 min following stimulation. Pharmacological inhibition with specific kinase inhibitors revealed the participation of protein kinase C, Src family kinase, and phosphatidylinositol 3-kinase (PI3-K) upstream of betaPIX. Both p21-activated kinase and reactive oxygen species played key roles in cytoskeletal reorganization downstream of betaPIX-Rac1. Taken together, our results suggest that betaPIX is involved in Ang II-induced VSMC migration.

Female counterpart of shawl scrotum in aarskog-scott syndrome

Aarskog-Scott syndrome (ASS) is an X-linked disorder characterized by facial, skeletal and genital anomalies, including penoscrotal transposition in males. We report on a girl from a family with ASS who exhibits a transposition of the clitoris.

Expressão da proteína recombinante RasGEF1b: um novo fator de troca de nucleotídeos guanina associado à proteína Ras induzido pelo Trypanosoma cruzi / Expression of the recombinant protein RasGEF1b: a new factor of guanina exchange of nucleotídeos associate to induced the Ras protein for the Trypanosoma cruzi

RasGEF1b é um fator de troca de nucleotídeos guanina (GEF) hipotético e altamente conservado. Esse gene contém um domínio RASGEFN com um motivo zíper de leucina e um domínio RASGEF com três sítios de localização nuclear. A expressão do mRNA do RasGEF1b em macrófagos é induzida por diferentes agonistas de receptores do tipo Toll (TLRs), tais como LPS (TLR4), GPI-mucina (TLR2) e Poli I:C (TLR3). A fim de expressar a proteína recombinante, nós clonamos o cDNA do RasGEF1b no vetor pQE-30, utilizado para transformar bactérias E. coli (XL1-Blue). A His-RasGEF1b expressa em bactérias foi purificada utilizando tampão com alto conteúdo de uréia, seguido por cromatografia de afinidade utilizando resina carregada com níquel. A expressão da proteína foi confirmada em gel 2D, análise por espectometria de massa e Western blotting utilizando um anticorpo monoclonal anti-His. Além disso, o cDNA do RasGEF1b foi inserido em um plasmídeo que permite a fusão do epitopo FLAG (pFLAGCMV2) com a proteína RasGEF1b. O pFLAGCMV2 codificando o cDNA do RasGEF1b foi utilizado para transfectar células HEK293T e a expressão protéica foi avaliada com gel 2D gel e Western blotting utilizando um anticorpo monoclonal anti-FLAG. A proteína reconhecida pelo anti-FLAG mostrou um peso molecular aparente de 56 KDa e ponto isoelétrico de 7,25. Utilizando a técnica de centrifugação diferencial e anticorpos monoclonais para as proteínas específicas das diferentes frações subcelulares, nós demonstramos que a proteína FLAG-RasGEF1b estava presente principalmente nas frações de núcleo e de membranas pesadas. Através do alinhamento entre seqüências da RasGEF1b de diferentes espécies filogeneticamente distintas vimos que esta proteína é altamente conservada com similaridade de 57 por cento a 97 por cento em relação à RasGEF1b murina.