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Genetics and exercise: an introduction
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Claude Bouchard, Henning Wackerhage
Other types of small DNA variants are variable number of repeat sequences. These are DNA variants where 2, 3 or more nucleotides are repeated multiple times. For instance, there is an abundance of CA dinucleotide repeats in the human genome. Some people may carry as few as 100 copies of the CA repeat at a given chromosomal site, whilst others may carry 10,000 or more copies of the repeat. Such repeat sequences are like a DNA fingerprint of an individual and are commonly used in forensic science to match DNA samples to an individual. One copy number variation occurs in the human AMY1 gene which encodes the starch-digesting enzyme, amylase. Humans have a large variation in the number of copies of the amylase gene, and people of agricultural societies that eat more starch have on average more copies than e.g. hunter-gatherers, who eat less starch (23).
Human Responses to Endotoxin: Role of the Genetic Background
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
The genomic structure of the IL-10 gene reveals nucleotide variations in the regulatory promoter region of the gene. Biallelic polymorphisms (Rsal and Maelll restriction sites) as well as dinucleotide repeats with 16 different alleles have been described. Associations between IL-10 genotype and the individual’s capacity of IL-10 secretion have been demonstrated. Innate low IL-10 secretion was correlated to a high rejection rate in organ transplant recipients. Another study reported a correlation between certain IL-10 microsatellite alleles and autoantibody production in lupus erythematosus. Data on secretory capacity of IL-10 in dependence of genomic variations of the IL-10 gene are still rare. Also, no data are available on allele frequencies and genotype distribution in sepsis. The importance of the IL-10 molecule in regulating inflammation deserves further investigation of the genetic background of IL-10 expression in human sepsis.
Molecular Genetics and Diagnostic Testing
Published in Merlin G. Butler, F. John Meaney, Genetics of Developmental Disabilities, 2019
One of the major factors in the development of techniques to analyze DNA was the discovery of proteins that cut DNA at specific base sequences called restriction enzymes. Each enzyme recognizes a different sequence and cuts the DNA into fragments of about 103-104 bases. For example, the enzyme EcoRI cuts at the sequence GAATTC, whereas HindIII cuts at AAGCTT. Variations in DNA sequence among individuals in a population that can be observed by digestion with restriction enzymes are termed restriction fragment length polymorphisms (RFLPs). RFLPs were very useful for early gene mapping studies but have been supplanted by microsatellite polymorphisms that are variations in small repeat sequences such as dinucleotide repeats, (CA)n.
Nutrigenomics in Parkinson’s disease: diversity of modulatory actions of polyphenols on epigenetic effects induced by toxins
Published in Nutritional Neuroscience, 2023
Moara Rodrigues-Costa, Matheus Santos de Sousa Fernandes, Gabriela Carvalho Jurema-Santos, Lílian Vanessa da Penha Gonçalves, Belmira Lara da Silveira Andrade-da-Costa
The genetic basis of PD began to be investigated after findings of a higher frequency of this disease in individuals with PD in their family history. It is now known that genetic mechanisms are also strongly involved in the pathogenesis of the disease in sporadic cases.19,20 Familial PD can be in autosomal dominant or autosomal recessive form, and usually occurs from structural mutations or variations in the number of genes involved in mitochondrial metabolism, oxidoreduction reactions and neuroinflammation.20,21 Sporadic PD represents more than 80% of the cases and may result from the combination of genetic susceptibility and exposure to environmental factors, such as air pollutants, pesticides, polychlorinated biphenyls, mycotoxins, organic solvents, heavy metals, inadequate diet or little physical activity.22 The genetic mechanisms behind sporadic PD may involve single nucleotide polymorphisms (SNPs) and dinucleotide repeat length and cumulative effects of rare mutations in PD-related genes on cellular pathways.22,23
Further Characterization of Hb Bronovo [α103(G10)His→Leu; HBA2: c.311A>T] and First Report of the Homozygous State
Published in Hemoglobin, 2020
Nikita Mehta, J. Martin Johnston, Molly Hein, Benjamin R. Kipp, Lea Coon, Michelle E. Savedra, James D. Hoyer, Rong He, Aruna Rangan, Min Shi, Jennifer L. Oliveira
Uniparental disomy (UPD) analysis of chromosomes 11 and 16 were also performed for the proband and his parents. Uniparental disomy studies were performed by a previously described technique [7,8]. In brief, samples were genotyped using PCR of chromosome-specific microsatellite markers (dinucleotide repeats). The markers used for chromosome 16 were D16S521, D16S418, D16S500, D16S3041, D16S3100, D16S3034, D16S3057, D16S503, D16S515, D16S516, D16S505 and D16S520; the markers used for chromosome 11 were D11S1363, D11S4046, D11S4146, D11S1760, D11S1338, D11S4116, D11S935, D11S987, D11S1314, D11S937, D11S901, D11S898, D11S4151, D11S1320 and D11S968. Diagnosis of UPD required that the proband carries at least two informative markers representing uniparental inheritance of chromosome 16, in addition to all informative markers for chromosome 11 showing biparental inheritance [9].
The effects of dopamine receptor genes on the trajectories of sport participation from adolescence through young adulthood
Published in Annals of Human Biology, 2020
Chung Gun Lee, Hyoyoul Moon, Seiyeong Park
For the DRD4 exon 3 variable number tandem repeat (VNTR; Van Tol et al. 1992) and the DRD5 dinucleotide repeat in the 5′ region (Sherrington et al. 1993), samples were analysed using polymerase chain reaction (PCR, ABI PRISM® 3130xl Genetic Analyzer). Since DRD4 short repeat alleles (i.e. 2–4 repeat alleles) show higher potency for dopamine-mediated coupling to adenylyl cyclase than the 7 repeat allele (Schoots and Van Tol 2003) and the DRD4 7 repeat allele has been linked to a decrease in postsynaptic inhibition (Oak et al. 2000), the number of DRD4 7 repeat alleles (0–2) is used to predict sport participation trajectories. The DRD5 148 bp allele is the most prevalent and has been related to decreased DRD5 expression levels, a predisposition to attention problems, poor inhibitory control and substance dependence (see Supplementary material). The number of DRD5 148 bp alleles (0–2) is, therefore, used to predict sport participation trajectories.