p.Gln318X and p.Val281Leu as the Major Variants of CYP21A2 Gene in Children with Idiopathic Premature Pubarche

Premature pubarche (PP) is the appearance of sexual hair in children before puberty. The PP phenotype may attribute to nonclassic congenital adrenal hyperplasia (NC-CAH). In this study, we investigated the role of CYP21A2 gene variants in patients with PP in the Iranian population. Forty patients (13 males and 27 females), clinically diagnosed with PP, were analyzed for molecular testing of CYP21A2 gene variants. Direct sequencing was performed for the samples. Also, gene dosage analysis was performed for the cases. Fourteen patients (35%) had a mutation of p.Gln318X and p.Val281Leu, out of which 10% had regulatory variants. Approximately 10% of the patients were homozygous (NC-CAH). 78.5% (11/14) of patients had trimodular RCCX of which 5 patients had two copies of CYP21A1P pseudogene. The prevalence of p.Val281Leu was higher than p.Gln318X in PP patients. In conclusion, CYP21A2 variant detection has implications in the genetic diagnosis of PP phenotype. The genetic characterization of the CYP21A2 gene is important for characterizing the variable phenotype of carriers and genetic counseling of PP and NC-CAH patients.

Download Full-text

Characterization of Caenorhabditis elegans Homologs of the Down Syndrome Candidate Gene DYRK1A

Genetics ◽

10.1093/genetics/163.2.571 ◽

2003 ◽

Vol 163 (2) ◽

pp. 571-580 ◽

Cited By ~ 1

Author(s):

William B Raich ◽

Celine Moorman ◽

Clay O Lacefield ◽

Jonah Lehrer ◽

Dusan Bartsch ◽

...

Keyword(s):

Down Syndrome ◽

Caenorhabditis Elegans ◽

Trisomy 21 ◽

Gene Dosage ◽

Inducible Promoters ◽

C Elegans ◽

Dual Specificity ◽

Specificity Protein

Abstract The pathology of trisomy 21/Down syndrome includes cognitive and memory deficits. Increased expression of the dual-specificity protein kinase DYRK1A kinase (DYRK1A) appears to play a significant role in the neuropathology of Down syndrome. To shed light on the cellular role of DYRK1A and related genes we identified three DYRK/minibrain-like genes in the genome sequence of Caenorhabditis elegans, termed mbk-1, mbk-2, and hpk-1. We found these genes to be widely expressed and to localize to distinct subcellular compartments. We isolated deletion alleles in all three genes and show that loss of mbk-1, the gene most closely related to DYRK1A, causes no obvious defects, while another gene, mbk-2, is essential for viability. The overexpression of DYRK1A in Down syndrome led us to examine the effects of overexpression of its C. elegans ortholog mbk-1. We found that animals containing additional copies of the mbk-1 gene display behavioral defects in chemotaxis toward volatile chemoattractants and that the extent of these defects correlates with mbk-1 gene dosage. Using tissue-specific and inducible promoters, we show that additional copies of mbk-1 can impair olfaction cell-autonomously in mature, fully differentiated neurons and that this impairment is reversible. Our results suggest that increased gene dosage of human DYRK1A in trisomy 21 may disrupt the function of fully differentiated neurons and that this disruption is reversible.

Download Full-text

Detection of Folliculin Gene Mutations in Two Chinese Families with Birt-Hogg-Dube Syndrome

BioMed Research International ◽

10.1155/2017/8751384 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Lv Liu ◽

Kai Yang ◽

Xiang Wang ◽

Zhihui Shi ◽

Yifeng Yang ◽

...

Keyword(s):

Direct Sequencing ◽

Mrna Level ◽

Genetic Diagnosis ◽

Gene Mutations ◽

Renal Cysts ◽

Insertion Mutation ◽

Chinese Families ◽

Increased Risk ◽

Pulmonary Cysts

Birt-Hogg-Dube syndrome (BHD, OMIM#135150) is a rare disease in clinic; it is characterized by skin fibrofolliculomas, pulmonary cysts with an increased risk of recurrent pneumothorax, renal cysts, and renal neoplasms. Previous studies have demonstrated that variants in folliculin (FLCN, NM_144997) are mainly responsible for this disease. In this research, we enrolled two BHD families and applied direct sequencing of FLCN to explore the genetic lesions in them. Two FLCN mutations were identified: one is a novel deletion variant (c.668delA/p.N223TfsX19), while the other is a previously reported insertion mutation (c.1579_1580insA/p.R527QfsX75). And the pathogenicity of both variants was confirmed by cosegregation assay. Bioinformatics analysis showed that c.668delA may lead to functional haploinsufficiency of FLCN because mRNA carrying this mutation exhibits a faster degradation rate comparing to the wild type. Real-time qPCR also confirmed that the mRNA level of FLCN expression in the proband was decreased significantly compared with the controls, which may disrupt the mTOR pathway and lead to BHD. The insertion mutation (c.1579_1580insA) was predicted to cause a prolonged amino acid sequence of FLCN. The present identification of two mutations not only further supports the important role of tumor suppressor FLCN in BHD and primary spontaneous pneumothorax, but also expands the spectrum of FLCN mutations and will provide insight into genetic diagnosis and counseling of families with BHD.

Download Full-text

“Single-nucleus RNA-seq2 reveals a functional crosstalk between liver zonation and ploidy”

10.1101/2020.07.11.193458 ◽

2020 ◽

Author(s):

M. L. Richter ◽

I.K. Deligiannis ◽

A. Danese ◽

E. Lleshi ◽

P. Coupland ◽

...

Keyword(s):

Gene Expression ◽

Gene Dosage ◽

Cellular Heterogeneity ◽

Cell Populations ◽

Rna Seq ◽

Liver Zonation ◽

Single Nucleus ◽

Different Levels

AbstractSingle-cell RNA-seq reveals the role of pathogenic cell populations in development and progression of chronic diseases. In order to expand our knowledge on cellular heterogeneity we have developed a single-nucleus RNA-seq2 method that allows deep characterization of nuclei isolated from frozen archived tissues. We have used this approach to characterize the transcriptional profile of individual hepatocytes with different levels of ploidy, and have discovered that gene expression in tetraploid mononucleated hepatocytes is conditioned by their position within the hepatic lobe. Our work has revealed a remarkable crosstalk between gene dosage and spatial distribution of hepatocytes.

Download Full-text

Detection and characterization of clustered regularly interspaced short palindromic repeat-associated endoribonuclease gene variants in Vibrio parahaemolyticus isolated from seafoods and environment

Veterinary World ◽

10.14202/vetworld.2019.689-695 ◽

2019 ◽

Vol 12 (5) ◽

pp. 689-695

Author(s):

Pallavi Baliga ◽

Malathi Shekar ◽

Moleyur Nagarajappa Venugopal

Keyword(s):

Polymerase Chain Reaction ◽

Vibrio Parahaemolyticus ◽

Genotypic Variation ◽

Gene Variants ◽

Chain Reaction ◽

Pcr Products ◽

Short Palindromic Repeat ◽

Polymerase Chain

Aim: In Vibrio parahaemolyticus, the clustered regularly interspaced short palindromic repeat (CRISPR)-associated cas6 endoribonuclease gene has been shown to exhibit sequence diversity and has been subtyped into four major types based on its length and composition. In this study, we aimed to detect and characterize the cas6 gene variants prevalent among V. parahaemolyticus strains isolated from seafoods and environment. Materials and Methods: Novel primers were designed for each of the cas6 subtypes to validate their identification in V. parahaemolyticus by polymerase chain reaction (PCR). In total, 38 V. parahaemolyticus strains isolated from seafoods and environment were screened for the presence of cas6 gene. Few representative PCR products were sequenced, and their phylogenetic relationship was established to available cas6 gene sequences in GenBank database. Results: Of the 38 V. parahaemolyticus isolates screened, only about 40% of strains harbored the cas6 endoribonuclease gene, among which 31.6% and 7.9% of the isolates were positive for the presence of the cas6-a and cas6-d subtypes of the gene, respectively. The subtypes cas6-b and cas6-c were absent in strains studied. Sequence and phylogenetic analysis also established the cas6 sequences in this study to match GenBank sequences for cas6-a and cas6-d subtypes. Conclusion: In V. parahaemolyticus, the Cas6 endoribonuclease is an associated protein of the CRISPR-cas system. CRISPR-positive strains exhibited genotypic variation for this gene. Primers designed in this study would aid in identifying the cas6 genotype and understanding the role of these genotypes in the CRISPR-cas immune system of the pathogen.

Download Full-text

Diagnosis of milder forms of phenylketonuria in the population of the Sverdlovsk region

Nauchno-prakticheskii zhurnal «Medicinskaia genetika» ◽

10.25557/2073-7998.2020.07.69-70 ◽

2020 ◽

pp. 69-70

Author(s):

С.С. Дерябина ◽

О.В. Лагутина ◽

Т.И. Беляева ◽

Н.В. Никитина ◽

В.К. Подолина ◽

...

Keyword(s):

Health Care ◽

Genetic Study ◽

Gold Standard ◽

Direct Sequencing ◽

Genetic Diagnosis ◽

Gene Variants ◽

New Approach ◽

Additional Testing ◽

Mother And Child ◽

Pah Gene

В работе представлены результаты расширенного генетического исследования 39 детей, наблюдавшихся в КДЦ «Охрана здоровья матери и ребенка» (г. Екатеринбург) с диагнозом «гиперфенилаланинемия». Анализ результатов обследования детей (у 13-ти пробандов наличие варианта R408W в гетерозиготном состоянии) показал, что поиск рекуррентных вариантов гена с использованием панели для ДНК-диагностики не дает ожидаемой верификации диагноза и требует дополнительного тестирования. Прямое секвенирование гена PAH позволило подтвердить диагноз «фенилкетонурия» (ФКУ) у 35 пробандов (89,8%) - у них обнаружено по 2 измененных аллеля. Еще у 4-х пациентов обнаружен только один патогенный вариант. Исследование ДНК родителей и сибсов указало на семейный вариант наследования всех выявленных мутаций. В результате проведенного исследования спектр патологии гена PAH, характерный для популяции Свердловской области, претерпел существенные изменения, что требует нового подхода к генодиагностике данной наследственной патологии в регионе. The paper presents the results of an extended genetic study of 39 children observed in the MC “Health Care of Mother and Child” (Ekaterinburg) with a «hyperphenylalaninemia». An analysis of the previously known results of the study in these patients (the p. R408W variant in the heterozygous in 13 probands) showed that the search for recurrent gene variants using the panel does not give the expected proving of the diagnosis and requires additional testing. Applying the «gold standard» of diagnosis - direct sequencing of the PAH gene, the diagnosis of phenylketonuria (PKU) was confirmed in 35 probands (89.8%) - 2 altered alleles were found in them, one pathogenic variant was found in 4 others. A study of the DNA of parents and siblings indicated a families’ variants of inheritance for all identified mutations. As a result of the study, the pathology spectrum of the PAH gene, currently in use for the population of the Sverdlovsk region, has undergone significant changes, which require a new approach to the genetic diagnosis of this hereditary pathology in the region.

Download Full-text

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104716 ◽

1988 ◽

Vol 46 ◽

pp. 530-531

Author(s):

L. T. Germinario

Keyword(s):

Background Radiation ◽

Metal Cluster ◽

Single Element ◽

Beam Diameter ◽

X Rays ◽

X Ray ◽

Major Interest ◽

Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Download Full-text