Role Of Inheritance Research Articles

Public Health Genetics – Challenging “Public Health at the Crossroads”

Dear public health professionals, Honestly, isn’t it time to ask whether or not we are doing “the right things”in public health? Are our present public health strategies evidence-based? The public health agenda demands a vision that reaches beyond research to the application of public health and the determination of it’s impact. In this scenario what is the role of genomics? In the past twenty years, advances in genome research have revolutionised what is known about the role of inheritance in health and disease.[1] Nowadays,we know that our DNA determines not only the cause of single-gene disorders, but also determines our predisposition to common diseases.Whereas medicine is currently undergoing extraordinary developments from its morphological and phenotype orientation to a molecular and genotype orientation, promoting the importance of prognosis and prediction, public health practice has to date concerned itself with environmental determinants of health and disease and has paid scant attention to genetic variations within the population. The advances brought about by genomics is changing these perceptions.[2,3] Many predict, that this knowledge will enable health promotion messages and disease prevention programmes to be specifically directed at susceptible individuals or at subgroups of the population, based on their genetic profile.[4,5] The new technologies will allow researchers to examine genetic mutations at the functional genomic unit level, and to better understand the significance of environmental factors such as noxious agents, nutrition and personal behaviour in relation to the causation of diseases such as cardiovascular diseases, psychiatric disorders and infectious diseases.

Role of evolution by natural selection in population dynamics.

Using a Monte Carlo approach we study the role of inheritance and natural selection in the dynamics of populations. We show that a population subject to inheritance has a much better chance of survival in a given condition than a population where new generations do not inherit genomes of their parents. The dependence of the survival chance on such factors as selection pressure, fecundity, or carrying capacity of the system is much stronger when selection and inheritance are present. We demonstrate, in accordance with biological observations, that in certain conditions evolution can save a population which would perish without it.

Dietary sodium and blood pressure.

The importance of dietary sodium chloride in the regulation of blood pressure has received much attention over the past few years. This area of research and knowledge has been controversial for several reasons. The major reason for controversy is that the science of the relationship is difficult to ascertain. Population science is limited by the narrow range of dietary sodium intake by most populations and individuals and the multiple confounders in those populations at the extremes of intake. Results from clinical trials have been difficult to interpret because of the difficulty in maintaining a given level of sodium intake over a period of time sufficient for study. Furthermore, basic science studies have been challenged by identifying appropriate models that mimic salt-sensitive hypertension in humans. Moreover, a lack of a well-funded proponent in industry complicates the research challenges. Guyton’s concept that the role of the kidney in handling sodium is key to the long-term regulation of blood pressure is now generally accepted.1 However, the exact role that dietary sodium plays in this relationship remains controversial. The relationship between renal handling of sodium and blood pressure is apparently influenced by a complex combination of factors including nutritional, other environmental, genetic, neurohormonal, and metabolic factors. The skepticism of many regarding the role of dietary sodium in blood pressure regulation and control has been tempered by the results of the DASH sodium study.2 Most acknowledge that this study reliably confirmed the benefit of dietary sodium restriction in blood pressure management. The study showed a dose-dependent impact of dietary sodium restriction on blood pressure in older hypertensive and nonhypertensive subjects. For many interested in this area of research, the questions have shifted as a result of the DASH sodium study. Rather than questioning whether dietary sodium is important, many investigators have turned their …

New developments in the pathophysiology of gastro-oesophageal reflux disease (GERD): implications for patient management.

The spectrum of gastro-oesophageal reflux disease (GERD) has expanded; indeed the majority of individuals with symptomatic GERD do not have erosive reflux disease (ERD); this group has been referred to as nonerosive or negative-endoscopy reflux disease (NERD). There may be important differences between NERD and ERD in terms of pathophysiology and management. Thus, NERD patients appear relatively resistant to proton pump inhibitors and may not be good surgical candidates. The clinician caring for patients with GERD must therefore be aware of the full spectrum of GERD and of the pathophysiological and therapeutic implications of NERD. Recent twin studies have revealed that genetic factors play a role in GERD and form the basis for future studies on the role of inheritance in the various manifestations of GERD. Several recent investigations have reaffirmed the primacy of acid reflux in the pathogenesis of GERD and have also provided insights into the pathophysiology of postprandial heartburn. Transient lower oesophageal sphincter relaxations and hiatal hernias have emerged as major and interacting factors in the genesis of reflux events and in the potentiation of acid exposure; the former are attracting considerable attention as a potential therapeutic target. Nocturnal acid breakthrough, which has been implicated in the failure of some patients to respond to high doses of proton pump inhibitors, appears, on further examination, to be a gastric rather than an oesophageal phenomenon, and may not be of clinical or therapeutic importance.

The role of inheritance in sporadic Parkinson's disease

The role of inheritance in sporadic Parkinson's disease

The role of inheritance in sporadic Parkinson's disease: evidence from a longitudinal study of dopaminergic function in twins.

Despite the major finding of a genetic defect being responsible for the Parkinson's disease (PD) phenotype in some kindreds with dominantly transmitted PD, the role of inheritance in the cause of the more widespread sporadic form of the disease is still unclear. Twin studies are a classic tool for assessing the influence of hereditary factors in diseases; however, the application of this approach to late-onset illnesses, like PD, poses some problems because of the identification of subclinical cases. In the present longitudinal study we have used [18F]dopa and positron emission tomography to study dopaminergic function in twin pairs at baseline clinically discordant for PD. At baseline, the concordance for subclinical striatal dopaminergic dysfunction was found to be significantly higher in 18 monozygotic than in 16 dizygotic twin pairs (55% vs 18%, respectively). The asymptomatic monozygotic cotwins all showed progressive loss of dopaminergic function over 7 years and 4 developed clinical PD. None of the dizygotic twin pairs became clinically concordant. At follow-up, the combined concordance levels for subclinical dopaminergic dysfunction and clinical PD were 75% in the 12 monozygotic and 22% in the 9 dizygotic twin pairs evaluated twice. Our findings suggest a substantial role for inheritance in sporadic PD.

Reproductive skew and the threat of eviction: a new perspective

Most recent models of the partitioning of reproduction attempt to explain patterns of skew on the assumption that dominant individuals have complete control over breeding opportunities within the group, but may nevertheless concede a share of direct reproduction to subordinates as an incentive to remain peacefully in the association. Although these models may be applicable to some animal societies, we argue that they fail to provide a comprehensive theory of skew. Instead, we suggest that subordinates may often be able to claim unsanctioned reproduction for themselves, but will be forced to exercise a degree of reproductive restraint lest they incite ejection by the dominant. Reproductive skew, in other words, may reflect the threat of ejection (inducing subordinate restraint) rather than the threat of subordinate departure (inducing reproductive concessions by dominants). We present a simple ESS model of reproductive skew under these circumstances, which demonstrates that a shift in emphasis from reproductive concessions by dominants to reproductive restraint on the part of subordinates, radically alters the predictions of skew models. High group productivity, high relatedness and (when group members are related) strong ecological constraints are all expected to lead to reduced skew (the opposite conclusions to those of previous, concession-based analyses). The reason is that these factors reduce the benefits (or increase the costs) of ejection to the dominant, who therefore does best to tolerate more subordinate reproduction.

Genetic studies in forensic psychiatry

Integration of biological variables in psychiatric research is essential. An example is the attempt to identify biological mechanisms which causes vulnerability to alcoholism. Another is the connection between serotonin metabolite [5-HIAA] concentration and impulsive behavior, including violent impulsive acts. Genetic analysis is an increasingly powerful tool due to methodological advances and is applicable to a wide range of behaviors in which a role for inheritance is indicated by studies in twins. We are attempting to identify genes for alcoholism—a psychiatric disease closely associated with impulsive and violent behaviors—by a combination of linkage and direct gene analysis approaches in the Finnish population. Finns represent a relative isolate where heterogeneities of gene and environment are reduced. Findings include our recently replicated association of a tryptophan hydroxylase to suicidality in impulsive alcoholics.

Genetic Testing for Cancer Risk Assessment: A Review

Both environmental factors and an inherited predisposition influence carcinogenesis. The direct role of inheritance in the development of cancer is evident in familial cancer syndromes. These syndromes predispose to cancer through the inheritance of a mutation in a single gene in affected carriers. While many inherited cancer syndromes are rare, an inherited predisposition is directly responsible for 5%-10% of all colon and breast cancers. Complex multigenic inheritance plays an important role in cancer predisposition for the population at large. The identification of genes responsible for an inherited predisposition to colon and breast cancer syndromes has directed public attention to genetic testing for susceptibility to cancer. Assays are currently available to determine individual susceptibility to specific cancers. Cancer genetic testing is currently a time-consuming and complex procedure which requires expertise in its application, interpretation, and follow-up strategic planning. This review discusses cancer genetics and its application to individual and family cancer risk assessment with particular emphasis on breast and colon cancer.

The Role of Family Help in the Housing Decisions of Young People

Recent debates about flows of help within the family have indicated considerable diversity according to the type of help (money, services), and ages and gender of those involved, and have shown that values are only a partial guide to the scale of such flows. This paper focuses on a particular occasion for help, young people's housing, and a particular region, South-East England, where one would expect family financial help to be high given the capacity to help of older generations (due to higher average incomes and wealth) and the affordability problems faced by young people. It is shown that contrary to hypothesis only 12% of a sample of young people had received financial help for housing purposes since they had left home, less than found in previous studies with different samples. The amounts involved were less than young people believed their parents could afford. The role of inheritance was also found to be minor. The results from the different studies are explained as due to changes in the housing market, changing values regarding financial help and differences among the samples. Intensive re-interviews with three households from very different backgrounds are used to show the different ways in which family help operates.

Towards reducing the incidence of colorectal cancer: the role of inheritance and diet.

Towards reducing the incidence of colorectal cancer: the role of inheritance and diet.

Contagion in schizophrenia: a critique of Crow and Done (1986).

This article discusses the literature on the possible role of viruses in the development of schizophrenia and outlines the evidence that compelled Crow and Done (1986) to reject a horizontal contagion hypothesis (e.g., sibling to sibling transmission). We posit a genetically determined age after which one becomes vulnerable to the illness, rather than a strict age of onset. We also propose an environmentally determined range of resistance to this susceptibility as an alternative conceptualization of the role of inheritance and of viral exposure in the etiology of the disease. The predictions derived from our new model fit the findings of Crow and Done and are consistent with the older literature of possible viral factors, thus reaffirming the horizontal contagion hypothesis.

Timescales and the role of inheritance in long‐term landscape evolution, northern New England, Australia

AbstractLandscape evolution in northern New England is characterized by the persistence of landforms over long time periods. The topography in the study area was initiated by Paleozoic diapiric intrusion of granitic rocks as highs within metasedimentary and volcanic rocks. This framework was probably reinforced by differences in the resistance of the massive igneous and the fractured metasedimentary rocks to erosion. As a result, both the Tertiary and present‐day relief of the area consists of uplands developed on granitic rocks partly overlain by Paleozoic volcanic rocks, and lowlands developed on Paleozoic metasediments. Extensive volcanism in the Tertiary had only a minimal effect on this relationship. A significant impact of Tertiary volcanism, however, was the diversion of major streams across topographic highs. Despite 19‐35 Ma of incision, these streams are still far from establishing equilibrium profiles and dissecting the highs.The persistence of topography for a timescale of the same order of magnitude as that conventionally thought to be required for planation is due to reduced denudation rates in a passive tectonic setting and the presence of erosion‐resistant Paleozoic igneous units. The latter influence is indicated by knickpoint persistence for 19‐35 Ma on streams diverted across these rocks. Since it is generally considered that such disequilibria are short‐lived features formed by Quaternary or ongoing deformation, this knickpoint persistence has important implications for landscape analyses that use disequilibria to assess recent tectonism in a landscape.

Studies in the Genetics of Obstructive Sleep Apnea: Familial Aggregation of Symptoms Associated with Sleep-related Breathing Disturbances

Previous studies of single families have suggested that familial factors may be important in the pathogenesis of obstructive sleep apnea. In this report, the role of inheritance in obstructive sleep apnea was assessed by quantitating the degree of familial clustering of symptoms associated with sleep-related breathing disorders. In total, 272 subjects from 29 families identified through an index case with obstructive sleep apnea and 21 control families with no relative known to have sleep apnea were studied with questionnaires that ascertained health status and symptoms. The unadjusted odds ratios of habitual or disruptive snoring, breathing pauses, and excessive day-time sleepiness in subjects with a single relative with the same symptom were 1.40 to 1.53 (p less than 0.05). Odds ratios increased progressively for subjects with increasing numbers of symptomatic relatives). Adjustment for body mass index, age, and gender modestly reduced these odds ratios to 1.33 to 1.42. These data suggest a significant familial aggregation of symptoms associated with sleep-disordered breathing that appears independent of familial similarities in weight.

The monkey's paw: The role of inheritance in the resolution of grief

Abstract Despite the common occurrence of the loss of a parent in adulthood, most research has either focused on the child's loss of a parent or parental loss of an adult child. Yet research has reported that the death of a parent is a stressful loss to adults. However, little research explores circumstances that might complicate loss. This research considers the role of inheritance in the resolution of grief. It was found that inheritance reflects, and perhaps intensifies, existing problems and conflicts between parents and siblings. When these prior issues are not problematic, inheritances leave a legacy that validates the life of the deceased and affirms relationships with survivors. The study also found a “settlement reaction” similar to anniversary reactions, suggesting that legal events influence the cycle of grief.

Object-oriented design and programming in medical decision support

The concept of object-oriented design and programming has recently received a great deal of attention from the software engineering community. This paper highlights the realisable benefits of using the object-oriented approach in the design and development of clinical decision support systems. These systems seek to build a computational model of some problem domain and therefore tend to be exploratory in nature. Conventional procedural design techniques do not support either the process of model building or rapid prototyping. The central concepts of the object-oriented paradigm are introduced, namely encapsulation, inheritance and polymorphism, and their use illustrated in a case study, taken from the domain of breast histopathology. In particular, the dual roles of inheritance in object-oriented programming are examined, i.e., inheritance as a conceptual modelling tool and inheritance as a code reuse mechanism. It is argued that the use of the former is not entirely intuitive and may be difficult to incorporate into the design process. However, inheritance as a means of optimising code reuse offers substantial technical benefits.

The Role of Genetics in Craniofacial Morphology and Growth

The nature of family resemblance and the role of inheritance in craniofacial growth and morphology have comprised a research focus for scientists in biological anthropology, genetics, anatomy, and dentistry since at least the mid-1940s. Research has focused on normal human variation, primate evolution, and the inheritance of craniofacial form for purposes of developmental and evolutionary studies, and to facilitate the prediction, recognition, and treatment of abnormal dental and facial patterns. Studies of craniofacial morphology involve both static morphology and growth. Examinations of craniofacial morphology usually provide a description or analysis of the craniofacial complex at a single stage in the growth process-e.g. adult craniofacial morphology. Alternatively, analyses of craniofacial growth examine the craniofacial complex at different ages to show how adult morphology is achieved. In this review I examine the following issues: how quantitatively inherited traits are analyzed; the most common methods used to estimate the proportion of the observed variation attributable to genetic factors; the history of model-

Quandaries Created by Unlikely Numbers in Some of Grossarth-Maticek's Studies

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Identification and mapping of a mouse gene influencing cerebellar folial pattern

Little is known about the role of inheritance in the pattern of cerebral cortical folding, or the causes of individual variation. Inouye and Oda ( J. Comp. Neurol., 190 (1980) 357–362) found that the cerebellar folial pattern varies markedly between inbred strains of mice and between individuals in a closed (non-inbred) colony, but shows little variation between individuals within a given inbred strain. They concluded that strain-specific variation in cerebellar folial pattern is under genetic control. In the present study, the folial pattern was examined in crosses between the C57BL/6J and DBA/2J inbred strains of mice, which differ in the presence or a single cerebellar fissure, and in recombinant inbred strains derived from a cross between the same strains. We found that variation is discrete, that neither phenotype is dominant, and that the strain difference is due predominantly to allelic differences at a single locus ( Cfp-1) on chromosome 4. Incomplete penetrance of the simpler pattern suggests that this genetic locus interacts in a probabilistic manner with epigenetic mechanisms involved in morphogenesis of the cerebellum.

The Role of Inheritance in Behavior

Inheritance plays a major role in behavior as shown by selection and strain studies for animal behavior and by twin and adoption studies for human behavior. Unlike simple Mendelian characteristics, genetic variance for behavioral dimensions and disorders rarely accounts for more than half of the phenotypic variance, and multiple genes with small effects appear to be involved rather than one or two major genes. Genetic research on behavior will be transformed by techniques of molecular biology that can be used to identify DNA sequences responsible for behavioral variation. However, the importance of nongenetic factors and the multigenetic control of behavior require new strategies to detect DNA markers that account for small amounts of behavioral variation.