A QTL on chromosome 3q23 influences processing speed in humans

Processing speed is a psychological construct that refers to the speed with which an individual can perform any cognitive operation. Processing speed correlates strongly with general cognitive ability, declines sharply with age, and is impaired across a number of neurological and psychiatric disorders. Thus, identifying genes that influence processing speed will likely improve understanding of the genetics of intelligence, biological aging, and the etiologies of numerous disorders. Previous genetics studies of processing speed have relied on simple phenotypes (e.g., mean reaction time) derived from single tasks. This strategy assumes, erroneously, that processing speed is a unitary construct. In the present study, we aimed to characterize the genetic architecture of processing speed by using a multi-dimensional model applied to a battery of cognitive tasks. Linkage and QTL-specific association analyses were performed on the factors from this model. The randomly ascertained sample comprised 1291 Mexican-American individuals from extended pedigrees. We found that performance on all three distinct processing-speed factors (Psychomotor Speed; Sequencing and Shifting and Verbal Fluency) were moderately and significantly heritable. We identified a genome-wide significant QTL on chromosome 3q23 for Psychomotor Speed (LOD = 4.83). Within this locus, we identified a plausible and interesting candidate gene for Psychomotor Speed (Z = 2.90, p = 1.86×10−03)

The Lothian Birth Cohort 1936: a study to examine influences on cognitive ageing from age 11 to age 70 and beyond

BACKGROUND: Cognitive ageing is a major burden for society and a major influence in lowering people's independence and quality of life. It is the most feared aspect of ageing. There are large individual differences in age-related cognitive changes. Seeking the determinants of cognitive ageing is a research priority. A limitation of many studies is the lack of a sufficiently long period between cognitive assessments to examine determinants. Here, the aim is to examine influences on cognitive ageing between childhood and old age. METHODS/DESIGN: The study is designed as a follow-up cohort study. The participants comprise surviving members of the Scottish Mental Survey of 1947 (SMS1947; N = 70,805) who reside in the Edinburgh area (Lothian) of Scotland. The SMS1947 applied a valid test of general intelligence to all children born in 1936 and attending Scottish schools in June 1947. A total of 1091 participants make up the Lothian Birth Cohort 1936. They undertook: a medical interview and examination; physical fitness testing; extensive cognitive testing (reasoning, memory, speed of information processing, and executive function); personality, quality of life and other psycho-social questionnaires; and a food frequency questionnaire. They have taken the same mental ability test (the Moray House Test No. 12) at age 11 and age 70. They provided blood samples for DNA extraction and testing and other biomarker analyses. Here we describe the background and aims of the study, the recruitment procedures and details of numbers tested, and the details of all examinations. DISCUSSION: The principal strength of this cohort is the rarely captured phenotype of lifetime cognitive change. There is additional rich information to examine the determinants of individual differences in this lifetime cognitive change. This protocol report is important in alerting other researchers to the data available in the cohort

Sex-specific cardiovascular comorbidities with associations in dermatologic and rheumatic disorders

Cardiology, dermatology, and rheumatology form a fascinating triad. Many skin and joint disorders are associated with cardiovascular comorbidities because they share etiologic elements. Female predominance is often remarkable and likely related to autoimmune pathology. Although studies have shown that X-encoded genes may be involved in the differences in immunity between males and females, other studies have also shown that sex chromosomes are irrelevant and that estrogens and androgens are responsible for the differences. The elevated immune activity in females provides a beneficial position in coping with a pathogenic stimulus but may also enhance their susceptibility to autoimmunity. The complexity of the immune system and its role as a defensive force against infection requires an armamentarium to precisely identify and selectively control inflammatory processes or cells which promote atherosclerosis. On the other hand, the inflammation in skin diseases seems to be an active source of diverse proinflammatory cytokines and chemokines which can predispose to cardiovascular comorbidities. Also, it has been shown that comorbidity disproportionately accelerates risk in women. The skin offers a readily available window to facilitate detection of risk factors or even to assist the diagnostic process regarding a variety of disorders, including those with cardiovascular involvement. Current imaging techniques provide exquisite capabilities for diagnosing and possibly even counteracting atherosclerotic plaque formation, before serious cardiovascular events occur. Combining imaging approaches (such as videocapillaroscopy, intravascular ultrasound, and FDG positron emission tomography) with insights based on immunology will likely accelerate advances in this area. We review major dermatologic manifestations and rheumatologic disorders which are associated with cardiac and vascular abnormalities. In particular we discuss sex-specific aspects concerning incidence and severity of cardiovascular disease associated with systemic sclerosis, rheumatoid arthritis, systemic lupus erythematosus, psoriasis, atopic dermatitis, and hidradenitis suppurativa

Advances in the assessment of cognitive skills using computer-based measurement

The impact of technology in the field of intellectual assessment has, for the most part, been limited to computerized administration and scoring. Anderson's (2001) theory of intelligence suggests that performance on traditional IQ measures is acquired via two main routes, thinking and dedicated processing systems known as modules. Empirical data used to support this relationship between the speed of basic processing and intellectual functioning have been evidenced primarily by correlations between measures of general intelligence and measures of inspection time (IT). These IT measures allow individuals to make a forced choice discrimination task without a motor component. Because only the time used to cognitively solve the problem is recorded, these responses typically occur in milliseconds. Many theorists (e. g., Burns & Nettelbeck, 2002; Deary, 2000; Jensen, 2006) consider IT to be a more "pure" measure of intelligence, because the influences of verbal skills, memory, and socialization are minimized and results are therefore considered to be more culture-fair. Until relatively recently, IT measurement was restricted to complex and expensive specialized laboratory equipment. This article describes the theoretical background and developmental process of a computer-based IT measure that is easily adaptable to accommodate the needs of the researcher. © 2011 Psychonomic Society, Inc