Cytogenetics and molecular genetics

2011 ◽  
pp. 1375-1380
Author(s):  
Dieter Meschede ◽  
Frank Tüttelmann
Keyword(s):  
Clinical Skills ◽  
Single Gene ◽  
Molecular Genetic ◽  
Practical Importance ◽  
Cell Lineage ◽  
Diagnostic Process ◽  
Meiotic Pairing ◽  
Molecular Tests ◽  
Endocrine Disturbances ◽  
Diagnostic Work

Genetic aberrations are important causes of spermatogenic and endocrine testicular failure. Often, clinical skills are insufficient to demonstrate the primary genetic nature of a gonadal disorder, and cytogenetic and molecular tests should be considered for the diagnostic process (Table 9.5.3.1) (1–7). They are helpful, not only for establishing the basic aetiology of certain types of male endocrine disturbances, but also in that karyotyping and some DNA tests have attained a pivotal role in genetic risk counselling for severely infertile couples. Also, the diagnosis of a chromosomal abnormality or single gene mutation in an infertile man can have repercussions for other members of his family. They may carry the same type of genetic aberration, and thus be at increased risk for inadvertent reproductive outcomes. The most time-honoured method in male endocrinology is the analysis of banded metaphase chromosome preparations from blood lymphocytes, which remains of undiminished practical importance (8, 9). This technique allows for the direct visualization of the complete set of chromosomes in a somatic cell lineage and provides information on both chromosome number and structure. However, a regular karyotype in somatic cells, such as lymphocytes, does not necessarily translate into normal meiotic pairing and segregation of the chromosomes in the germ cell lineage. Meiotic cell preparations and ejaculated spermatozoa may thus be included in the diagnostic work-up of an infertile man. The place of these techniques is more in the realm of research than of daily clinical practice, as discussed below. In contrast, several molecular genetic tests are firmly established as valuable diagnostic tools. Details concerning the two most important tests, mutation analysis of the CFTR gene and screening for Y-chromosomal microdeletions, are given below.

scholarly journals Proteinuria—take a closer look!

2020 ◽  
Vol 35 (4) ◽  
pp. 533-541 ◽  
Author(s):  
Arend Bökenkamp
Keyword(s):  
Kidney Disease ◽  
Protein Content ◽  
Molecular Genetic ◽  
Diagnostic Process ◽  
Total Protein Content ◽  
Non Invasive ◽  
Knowing That ◽  
Protein Reabsorption ◽  
Diagnostic Work ◽  
Work Up

AbstractProteinuria is a hallmark of kidney disease. Therefore, measurement of urine protein content plays a central role in any diagnostic work-up for kidney disease. In many cases, proteinuria analysis is restricted to the measurement of total protein content knowing that very high levels of proteinuria (nephrotic proteinuria) are characteristic of glomerular disease. Still, proteinuria can also be a manifestation of impaired tubular protein reabsorption or even be physiological. This review will discuss the physiology of renal protein handling and give guidance on a more sophisticated analysis of proteinuria differentiating albumin, low-molecular weight proteins and immunoglobulins. These non-invasive tests are available in most routine clinical laboratories and may guide the clinician in the diagnostic process before ordering far more expensive (molecular genetic testing) and/or invasive (kidney biopsy) diagnostics.

GENETIC CERTIFICATION OF FODDER CROPS BREEDING ACHIEVEMENTS

1970 ◽  
pp. 40-46
Author(s):  
V. M. Kosolapov ◽  
N. N. Kozlov ◽  
I. А. Klimenko ◽  
V. N. Zolotarev
Keyword(s):  
Dna Analysis ◽  
Molecular Genetic ◽  
Practical Importance ◽  
Genetic Identification ◽  
Necessary Condition ◽  
Forage Crops ◽  
Fodder Crops ◽  
Long Time ◽  
Analytical Review ◽  
Prospects Of Application

The methods of genetic identification of forage crops varieties and forms have significant scientific and practical importance in breeding and seed multiplication, in protection of author’s rights. At the current moment molecular markers on the base of DNA-polymorphism have been applied widely for these aims. This analytical review examines the possibilities and the prospects of application the different DNA-analysis methods for assessment of forage crops genetic diversity and for development the molecular-genetic passports of breeding achievements. The objective estimation of varieties structure and presence impurities is a necessary condition for improving the methodical approaches in approbation of crops and for decision the problems of timely variety-seed renovation and its systematic replacement. The system of DNA markers that registered in genetic passport will enable to keep the initial genetic structure of variety and to maintain it in production process during long time without fluctuations of agronomic important characteristics and properties. This factor is especially valuable for development the primary seed multiplication.

scholarly journals Stomatal Development in the Context of Epidermal Tissues

2021 ◽  
Author(s):  
Keiko U Torii
Keyword(s):  
Arabidopsis Thaliana ◽  
Molecular Genetic ◽  
Cell Lineage ◽  
Optimal Growth ◽  
Cell Types ◽  
State Transitions ◽  
Stomatal Development ◽  
Water Control ◽  
Pavement Cells ◽  
The Core

Abstract Background Stomata are adjustable pores on the surface of plant shoots for efficient gas exchange and water control. The presence of stomata is essential for plant growth and survival, and the evolution of stomata is considered as a key developmental innovation of the land plants, allowing colonization on land from aquatic environments some 450 million years ago. In the past two decades, molecular genetic studies using the model plant Arabidopsis thaliana identified key genes and signalling modules that regulate stomatal development: master-regulatory transcription factors that orchestrate cell-state transitions and peptide-receptor signal transduction pathways, which, together, enforce proper patterning of stomata within the epidermis. Studies in diverse plant species, ranging from bryophytes to angiosperm grasses, have begun to unravel the conservation and uniqueness of the core modules in stomatal development. Scope Here, I review the mechanisms of stomatal development in the context of epidermal tissue patterning. First, I introduce the core regulatory mechanisms of stomatal patterning and differentiation in the model species Arabidopsis thaliana. Subsequently, experimental evidence is presented supporting the idea that different cell types within the leaf epidermis, namely stomata, hydathodes pores, pavement cells, and trichomes, either share developmental origins or mutually influence each other’s gene regulatory circuits during development. Emphasis is taken on extrinsic and intrinsic signals regulating the balance between stomata and pavement cells, specifically by controlling the fate of Stomatal-Lineage Ground Cells (SLGCs) to remain within the stomatal-cell lineage or differentiate into pavement cells. Finally, I discuss the influence of inter-tissue-layer communication between the epidermis and underlying mesophyll/vascular tissues on stomatal differentiation. Understanding the dynamic behaviors of stomatal precursor cells and their differentiation in the broader context of tissue and organ development may help design plants tailored for optimal growth and productivity in specific agricultural applications and a changing environment.

scholarly journals Molecular genetics of bipolar disorder

2001 ◽  
Vol 178 (S41) ◽  
pp. s128-s133 ◽  
Author(s):  
Nick Craddock ◽  
Ian Jones
Keyword(s):  
Bipolar Disorder ◽  
Candidate Gene ◽  
Molecular Genetics ◽  
Ethical Issues ◽  
Association Studies ◽  
Single Gene ◽  
Molecular Genetic ◽  
Genetic Dissection ◽  
Adoption Studies ◽  
Candidate Gene Association

BackgroundA robust body of evidence from family, twin and adoption studies demonstrates the importance of genes in the pathogenesis of bipolar disorder. Recent advances in molecular genetics have made it possible to identify these susceptibility genes.AimsTo present an overview for clinical psychiatrists.MethodReview of current molecular genetics approaches and emerging findings.ResultsOccasional families may exist in which a single gene plays a major role in determining susceptibility, but the majority of bipolar disorder involves more complex genetic mechanisms such as the interaction of multiple genes and environmental factors. Molecular genetic positional and candidate gene approaches are being used for the genetic dissection of bipolar disorder. No gene has yet been identified but promising findings are emerging. Regions of interest include chromosomes 4p16, 12q23–q24, 16p13, 21q22, and Xq24–q26. Candidate gene association studies are in progress but no robust positive findings have yet emerged.ConclusionIt is almost certain that over the next few years the identification of bipolar susceptiblity genes will have a major impact on our understanding of disease pathophysiology. This is likely to lead to major improvements and treatment in patient care, but will also raise important ethical issues.

scholarly journals Recent Developments in Diagnosis and Care for Girls in Turner Syndrome

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Carolyn Bondy
Keyword(s):  
Turner Syndrome ◽  
Brain Size ◽  
Molecular Genetic ◽  
Oocyte Donation ◽  
Breath Holding ◽  
Chromosomal Anomalies ◽  
The Past ◽  
Molecular Tests ◽  
Effective Counseling ◽  
Recent Developments

The past decade produced important advances in molecular genetic techniques potentially supplanting the traditional cytogenetic diagnosis of Turner syndrome (TS). Rapidly evolving genomic technology is used to screen 1st trimester pregnancies for sex chromosomal anomalies including TS, and genomic approaches are suggested for the postnatal diagnosis of TS. Understanding the interpretation and limitations of new molecular tests is essential for clinicians to provide effective counseling to parents or patients impacted by these tests. Recent studies have advanced the concept that X chromosome genomic imprinting influences expression of the Turner phenotype and contributes to gender differences in brain size and coronary disease. Progress in cardiovascular MRI over the past decade has dramatically changed our view of the scope and criticality of congenital heart disease in TS. Cardiac MRI is far more effective than transthoracic echocardiography in detecting aortic valve abnormalities, descending aortic aneurysm, and partial anomalous pulmonary venous return; recent technical advances allow adequate imaging in girls as young as seven without breath holding or sedation. Finally, important developments in the area of gynecological management of girls and young women with TS are reviewed, including prognostic factors that predict spontaneous puberty and potential fertility and recent practice guidelines aimed at reducing cardiovascular risk for oocyte donation pregnancies in TS.

Epigenetics and Applied Anthropology

2021 ◽  
Author(s):  
Charles H. Klein
Keyword(s):  
Social Inequalities ◽  
Homo Sapiens ◽  
Single Gene ◽  
Molecular Genetic ◽  
Healthcare Providers ◽  
Basic Research ◽  
Sufficient Information ◽  
Theoretical Frameworks ◽  
Noncoding Dna ◽  
Wide Range

Since Francis Crick and James D. Watson’s discovery of DNA in 1953, researchers, policymakers, and the general public have sought to understand the ways in which genetics shapes human lives. A milestone in these efforts was the completion of the Human Genome Project’s (HGP) sequencing of Homo sapiens’ nearly three million base pairs in 2003. Yet, despite the excitement surrounding the HGP and the discovery of the structural genetic underpinnings of several debilitating diseases, the vast majority of human health outcomes have not been linked to a single gene. Moreover, even when genes have been associated with particular diseases (e.g., breast and colon cancer), it is not well understood why certain genetically predisposed individuals become ill and others do not. Nor has the HGP’s map provided sufficient information to understand the actual functioning of the human genetic code, including the role of noncoding DNA (“junk DNA”) in regulating molecular genetic processes. In response, a growing number of scientists have shifted their attention from structural genetics to epigenetics, the study of how genes express themselves in particular situations and environments. Anthropologists play roles in these applications of epigenetics to real-world settings. Their new theoretical frameworks unsettle the nature-versus-nurture binary and support biocultural anthropological research demonstrating how race becomes biology and embodies social inequalities and health disparities across generations. Ethnographically grounded case studies further highlight the diverse epigenetic logics held by healthcare providers, researchers, and patient communities and how these translations of scientific knowledge shape medical practice and basic research. The growing field of environmental epigenetics also offers a wide range of options for students and practitioners interested in applying the anthropological toolkit in epigenetics-related work.

scholarly journals DIFFERENTIAL DIAGNOSTICS OF INHERITED METABOLIC DISORDERS IN NEWBORNS

2020 ◽  
Vol 73 (6) ◽  
pp. 1211-1216
Author(s):  
Tetiana K. Znamenska ◽  
Olga V. Vorobiova ◽  
Тetiana V. Holota ◽  
Vera V. Kryvosheieva ◽  
Valeriy I. Pokhylko
Keyword(s):  
Metabolic Diseases ◽  
Differential Diagnostics ◽  
Inborn Errors ◽  
Molecular Tests ◽  
Inherited Metabolic Disorders ◽  
Expanded Newborn Screening ◽  
Confirmatory Tests ◽  
Pathogenetic Therapy ◽  
Diagnostic Work

The aim: To compose an applicable diagnostic checklist for neonatologists, pediatricians, and general practitioners who refer newborns with certain inherited metabolic diseases (IMDs) suspicion to confirmatory testing laboratories. Materials and methods: Analyzed international and generally, known national clinical guides and recommendations devoted to IMDs diagnostics, treatment and follow up. Results: Considering integral character of the diagnostic work-up of inborn errors of metabolism, authors of this article composed an applicable checklist that comprises set of data necessary for interpretation the positive results of expanded newborn screening and making decision of appropriate biochemical and molecular tests are required for confirmatory follow-up testing to establish the diagnosis and prescribe pathogenetic therapy. Conclusions: Properly filled checklist allow metabolic professionals to select appropriate confirmatory tests and interpret results obtained. Early IMDs diagnosis and prompt treatment initiation are crucial for positive outcomes and proved to be an effective tool to decrease levels of child disability and infant mortality.

Genetic epidemiology 2: molecular genetics

2003 ◽  
pp. 335-356
Author(s):  
David Collier ◽  
Tao Li
Keyword(s):  
Molecular Genetics ◽  
Single Gene ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Primary Objective ◽  
Great Success ◽  
Complex Disorder ◽  
Single Gene Disorders ◽  
Human Disorders ◽  
Rapid Pace

The previous chapter has focused on methods for identifying familial clustering of disorders or traits, and on methods for distinguishing between shared genetic and environmental influences. The primary objective for this chapter is to outline techniques for identifying specific genes responsible for an observed phenotype. The theoretical basis of complex and quantitative traits was established many decades ago. However practical methods for the efficient molecular analysis of the human genome have only recently emerged. Alongside these developments, the molecular genetic analysis of human disorders has moved at a rapid pace. Molecular genetics has focused on single gene disorders with great success, whereas for complex psychiatric disorders, few genetic risk factors have been identified. However the tools used by the complex disorder geneticist have evolved rapidly in the last few years and better strategies and statistical methods continue to appear. This chapter outlines some established and novel approaches to the analysis of the genetics of complex human disorders. A basic understanding of genetical statistics will be useful.

scholarly journals Mild Zellweger syndrome due to functionally confirmed novel PEX1 variants

2019 ◽  
Vol 61 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Patryk Lipiński ◽  
Piotr Stawiński ◽  
Małgorzata Rydzanicz ◽  
Maria Wypchło ◽  
Rafał Płoski ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Late Onset ◽  
Zellweger Syndrome ◽  
Diagnostic Process ◽  
Mr Images ◽  
Mild Phenotype ◽  
Autosomal Recessive Disorders ◽  
Branched Chain ◽  
Zellweger Spectrum Disorders ◽  
Diagnostic Work

Abstract Zellweger spectrum disorders (ZSD) constitute a group of rare autosomal recessive disorders characterized by a defect in peroxisome biogenesis due to mutations in one of 13 PEX genes. The broad clinical heterogeneity especially in late-onset presenting patients and a mild phenotype complicates and delays the diagnostic process. Here, we report a case of mild ZSD, due to novel PEX1 variants. The patient presented with an early hearing loss, bilateral cataracts, and leukodystrophy on magnetic resonance (MR) images. Normal results of serum very-long-chain fatty acids (VLCFA) and phytanic acid were found. Molecular diagnostics were performed to uncover the etiology of the clinical phenotype. Using whole exome sequencing, there have been found two variants in the PEX1 gene—c.3450T>A (p.Cys1150*) and c.1769T>C (p.Leu590Pro). VLCFA measurement in skin fibroblasts and C26:0-lysoPC in dried blood spot therefore was performed. Both results were in line with the diagnosis of ZSD. To conclude, normal results of routine serum VLCFA and branched-chain fatty acid measurement do not exclude mild forms of ZSD. The investigation of C26:0-lysoPC should be included in the diagnostic work-up in patients with cataract, hearing loss, and leukodystrophy on MR images suspected to suffer from ZSD.

scholarly journals Molecular Genetic Analysis of Nucleotide Polymorphisms Associated with Ethambutol Resistance in Human Isolates ofMycobacterium tuberculosis

2000 ◽  
Vol 44 (2) ◽  
pp. 326-336 ◽  
Author(s):  
Srinivas V. Ramaswamy ◽  
Amol G. Amin ◽  
Servet Göksel ◽  
Charles E. Stager ◽  
Shu-Jun Dou ◽  
...  
Keyword(s):  
Amino Acid ◽  
Single Gene ◽  
Molecular Genetic ◽  
Regulatory Region ◽  
Amino Acid Replacement ◽  
Molecular Genetic Analysis ◽  
Central Component ◽  
Nucleotide Polymorphisms ◽  
Molecular Change

ABSTRACT Ethambutol (EMB) is a central component of drug regimens used worldwide for the treatment of tuberculosis. To gain insight into the molecular genetic basis of EMB resistance, approximately 2 Mb of five chromosomal regions with 12 genes in 75 epidemiologically unassociated EMB-resistant and 33 EMB-susceptible Mycobacterium tuberculosis strains isolated from human patients were sequenced. Seventy-six percent of EMB-resistant organisms had an amino acid replacement or other molecular change not found in EMB-susceptible strains. Thirty-eight (51%) EMB-resistant isolates had a resistance-associated mutation in only 1 of the 12 genes sequenced. Nineteen EMB-resistant isolates had resistance-associated nucleotide changes that conferred amino acid replacements or upstream potential regulatory region mutations in two or more genes. Most isolates (68%) with resistance-associated mutations in a single gene had nucleotide changes in embB, a gene encoding an arabinosyltransferase involved in cell wall biosynthesis. The majority of these mutations resulted in amino acid replacements at position 306 or 406 of EmbB. Resistance-associated mutations were also identified in several genes recently shown to be upregulated in response to exposure of M. tuberculosis to EMB in vitro, including genes in theiniA operon. Approximately one-fourth of the organisms studied lacked mutations inferred to participate in EMB resistance, a result indicating that one or more genes that mediate resistance to this drug remain to be discovered. Taken together, the results indicate that there are multiple molecular pathways to the EMB resistance phenotype.

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