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Mendel's Laws (mendel + law)
Selected AbstractsThe construction of Mendel's lawsEVOLUTIONARY ANTHROPOLOGY, Issue 6 2008Article first published online: 22 DEC 200, Jonathan Marks Abstract While "Mendel's Laws" are generally taught as natural facts, they are actually pedagogical constructions, which originated in a series of lectures at Princeton in 1916. What accounts for their popularity? [source] Approaches to identify genes for complex human diseases: Lessons from Mendelian disorders,,HUMAN MUTATION, Issue 4 2003Michael Dean Abstract The focus of most molecular genetics research is the identification of genes involved in human disease. In the 20th century, genetics progressed from the rediscovery of Mendel's Laws to the identification of nearly every Mendelian genetic disease. At this pace, the genetic component of all complex human diseases could be identified by the end of the 21st century, and rational therapies could be developed. However, it is clear that no one approach will identify the genes for all diseases with a genetic component, because multiple mechanisms are involved in altering human phenotypes, including common alleles with small to moderate effects, rare alleles with moderate to large effects, complex gene,gene and gene,environment interactions, genomic alterations, and noninherited genetic effects. The knowledge gained from the study of Mendelian diseases may be applied to future research that combines linkage-based, association-based, and sequence-based approaches to detect most disease alleles. The technology to complete these studies is at hand and requires that modest improvements be applied on a wide scale. Improved analytical tools, phenotypic characterizations, and functional analyses will enable complete understanding of the genetic basis of complex diseases. Hum Mutat 22:261,274, 2003. Published © 2003 Wiley-Liss, Inc. [source] Mendelian randomization in nutritional epidemiologyNUTRITION REVIEWS, Issue 8 2009Lu Qi Nutritional epidemiology aims to identify dietary and lifestyle causes for human diseases. Causality inference in nutritional epidemiology is largely based on evidence from studies of observational design, and may be distorted by unmeasured or residual confounding and reverse causation. Mendelian randomization is a recently developed methodology that combines genetic and classical epidemiological analysis to infer causality for environmental exposures, based on the principle of Mendel's law of independent assortment. Mendelian randomization uses genetic variants as proxies for environmental exposures of interest. Associations derived from Mendelian randomization analysis are less likely to be affected by confounding and reverse causation. During the past 5 years, a body of studies examined the causal effects of diet/lifestyle factors and biomarkers on a variety of diseases. The Mendelian randomization approach also holds considerable promise in the study of intrauterine influences on offspring health outcomes. However, the application of Mendelian randomization in nutritional epidemiology has some limitations. [source] Replication of the tumor necrosis factor receptor,associated factor 1/complement component 5 region as a susceptibility locus for rheumatoid arthritis in a European family-based studyARTHRITIS & RHEUMATISM, Issue 9 2008F. A. S. Kurreeman Objective We recently showed, using a candidate gene approach in a case,control association study, that a 65-kb block encompassing tumor necrosis factor receptor,associated factor 1 (TRAF1) and C5 is strongly associated with rheumatoid arthritis (RA). Compared with case,control association studies, family-based studies have the added advantage of controlling potential differences in population structure and are not likely to be hampered by variation in population allele frequencies, as is seen for many genetic polymorphisms, including the TRAF1/C5 locus. The aim of this study was to confirm this association in populations of European origin by using a family-based approach. Methods A total of 1,356 western European white individuals from 452 "trio" families were genotyped for the rs10818488 polymorphism, using the TaqMan allelic discrimination assay. Results We observed evidence for association, demonstrating departure from Mendel's law, with an overtransmission of the rs10818488 A allele (A = 55%; P = 0.036). By taking into consideration parental phenotypes, we also observed an increased A allele frequency in affected versus unaffected parents (A = 64%; combined P = 0.015). Individuals carrying the A allele had a 1.2-fold increased risk of developing RA (allelic odds ratio 1.24, 95% confidence interval 1.04,1.50). Conclusion Using a family-based study that is robust against population stratification, we provide evidence for the association of the TRAF1/C5 rs10818488 A allele and RA in populations of European descent, further substantiating our previous findings. Future functional studies should yield insight into the biologic relevance of this locus to the pathways involved in RA. [source] The construction of Mendel's lawsEVOLUTIONARY ANTHROPOLOGY, Issue 6 2008Article first published online: 22 DEC 200, Jonathan Marks Abstract While "Mendel's Laws" are generally taught as natural facts, they are actually pedagogical constructions, which originated in a series of lectures at Princeton in 1916. What accounts for their popularity? [source] | |||||||||||||