China
Africa
Explore chapters and articles related to this topic
Epidemiology
Published in Lloyd N. Friedman, Martin Dedicoat, Peter D. O. Davies, Clinical Tuberculosis, 2020
Grant Theron, Ted Cohen, Christopher Dye
Besides environmental factors and concomitant illness, infection and the progression to active TB are also under human genetic control. That TB runs in families is well known but this observation confounds genes and possible transmission due to close contact. Among the genes associated with susceptibility to TB (e.g., twin studies, case−control studies) are those encoding the vitamin D receptor, natural resistance associated macrophage protein (NRAMP1), HLA, mannose binding lectin (MBL), ASAP1 actin and membrane remodeling protein, and the Toll-like receptors.91–100 Associations between human genetic polymorphisms and disease risk, clinical presentation, or outcome are typically determined by the interactions between genes and their environment.101,102 Investigations of genetic determinants have thus not yielded consistent results, as illustrated by studies of vitamin D receptor polymorphisms97,103 and clinical trials evaluating vitamin D supplementation describing an overall lack of impact on TB treatment outcomes.104
Single nucleotide polymorphisms and pregnancy complications
Published in Moshe Hod, Vincenzo Berghella, Mary E. D'Alton, Gian Carlo Di Renzo, Eduard Gratacós, Vassilios Fanos, New Technologies and Perinatal Medicine, 2019
Federica Tarquini, Giuliana Coata, Elena Picchiassi, Gian Carlo Di Renzo
Genetic polymorphism is an existence of two or more different alleles in one locus in DNA, more often than it is expected, according to mutation frequency in a population. Both the mutation and polymorphism are a qualitative and/or quantitative change in the genetic material. SNPs are point mutations, like insertion, deletion, or substitution of one of the nucleotides in a coding or uncoding DNA sequence. These are single-letter nucleotide changes that occur in 1% or more of the population. There are 12–15 million of such variants that have been meticulously catalogued by the human genome project in the publicly available database called dbSNP (http://www.ncbi.nlm.nih.gov/projects/SNP). A wide range of methods of finding polymorphisms is now available, like a genome-wide association study (GWAS) or genome-wide linkage study (GWLS). One study reported the results of the GWAS in which, as the first, a risk locus for preeclampsia on chromosome 2q14, near the inhibin ß B (INHBB) gene was identified. In that study, researchers had successfully genotyped 648,175 SNPs in 538 preeclampsia cases and 540 normal pregnancy controls with the usage of the Illumina OmniExpress-12 BeadChip (5).
Pharmacokinetics
Published in Sarah Armstrong, Barry Clifton, Lionel Davis, Primary FRCA in a Box, 2019
Sarah Armstrong, Barry Clifton, Lionel Davis
Genetic polymorphism Slow and fast acetylators (e.g. hydralazine)Suxamethonium apnoea (genetic abnormalities of plasma cholinesterase)
The impact of leptin and its receptor polymorphisms on type 1 diabetes in a population of northwest Iran
Published in Annals of Human Biology, 2022
Parviz Azimnasab-sorkhabi, Maryam Soltani-asl, José Roberto Kfoury, Petra Algenstaedt, Hakan Farzin Mehmetzade, Yashar Hashemi Aghdam
Genetic polymorphisms have the potential to support or even cause phenotypic diversities among people such as disease risk and medication responses. Characterisation of genetic polymorphisms that regulate gene expression and protein function may assist in the recognition of various variants (Jin et al. 2018). Several studies have revealed associations between polymorphisms and diabetes in different populations including the Iranian population. For instance, recently, it has been shown that in the Iranian population NeuroD1 Ala45Thr polymorphism is significantly associated with T1D (Soltani Asl et al., 2020). Importantly, leptin (LEP) and leptin receptor (LEPR) genes are potential candidates to contribute to the pathophysiology of diabetes, obesity, metabolic syndrome, and cancer (Nesrine et al. 2018; Cheng et al. 2020). The LEP is an adipocyte-derived peptide hormone and plays several important roles in human physiology (Hussain et al. 2015; Yan et al. 2016). Therefore, the LEP G2548A and LEPR Q223R polymorphisms are potential targets to further studies at the genetic level to expand our knowledge regarding involved mechanisms in diabetes.
A clinical approach to treatment resistance in depressed patients: What to do when the usual treatments don’t work well enough?
Published in The World Journal of Biological Psychiatry, 2021
Seetal Dodd, Michael Bauer, Andre F. Carvalho, Harris Eyre, Maurizio Fava, Siegfried Kasper, Sidney H. Kennedy, Jon-Paul Khoo, Carlos Lopez Jaramillo, Gin S. Malhi, Roger S. McIntyre, Philip B. Mitchell, Angela Marianne Paredes Castro, Aswin Ratheesh, Emanuel Severus, Trisha Suppes, Madhukar H. Trivedi, Michael E. Thase, Lakshmi N. Yatham, Allan H. Young, Michael Berk
The Deconstructing Depression approach does not provide simple or easily operationalised criteria that can be substituted for current TRD criteria in a research protocol. Because there have not been any head to head comparisons of different approaches to TRD to assess their clinical utility and prognostic value, this should be a research priority. The approach described in this paper assumes that non-remission to antidepressant treatment is attributable to many possible variables that need to be considered on a case by case basis, with biological factors, such as metaboliser status, only accounting for a small proportion of cases. However, this approach may underestimate the importance of biological variables, where metaboliser status may be only one of several biological variables that contribute towards antidepressant treatment failure. A study by the European Group for the Study of Resistant Depression identified several genetic variables associated with TRD, but interestingly found no association between CYP gene polymorphisms and TRD, suggesting that the significance of metaboliser status may be less important than other genetic polymorphisms (Bartova et al. 2019). In addition, the prevalence of different variables will vary geographically, ethnographically, and between different health services and health service models.
Genetic polymorphisms for BDNF, COMT, and APOE do not affect gait or ankle motor control in chronic stroke: A preliminary cross-sectional study
Published in Topics in Stroke Rehabilitation, 2021
Rehab Aljuhni, Brice T. Cleland, Stephen Roth, Sangeetha Madhavan
There is much inter-individual variability in functional recovery after stroke.5,6 For example, motor recovery can vary from minimal to full recovery, making it difficult to predict with biomarkers. Genetic polymorphisms, frequently termed single nucleotide polymorphisms (SNP), are variations involving a change of nucleic acids in DNA sequence at one or more positions that may affect the function and expression of the gene. In other words, SNPs are DNA variations that (depending on the location) may affect gene expression, protein production, and bodily function. Many SNPs have no discernible effects, but others may explain interindividual differences in bodily functions, including functional recovery after stroke. Previous studies have suggested that polymorphisms of genes that encode brain-derived neurotrophic factor (BDNF), apolipoprotein E (APOE), and catechol-O-methyltransferase (COMT) influence functional recovery, cognitive and motor learning, and capacity for neuroplasticity in individuals with and without neurological impairment.7,8 It is unclear whether these polymorphisms influence recovery of walking and ankle motor control in chronic stroke.