Insulin Resistance, Hyperinsulinemia, and LH: Relative Roles in Peripubertal Obesity-Associated Hyperandrogenemia.

Context: Peripubertal obesity is associated with variable hyperandrogenemia, but precise mechanisms remain unclear.

Objective: To assess insulin resistance, hyperinsulinemia, and LH roles in peripubertal obesity-associated hyperandrogenemia.

Design: Cross-sectional analysis.

Childhood obesity and its impact on the development of adolescent PCOS.

Obesity exacerbates the reproductive and metabolic manifestations of polycystic ovary syndrome (PCOS). The symptoms of PCOS often begin in adolescence, and the rising prevalence of peripubertal obesity has prompted concern that the prevalence and severity of adolescent PCOS is increasing in parallel. Recent data have disclosed a high prevalence of hyperandrogenemia among peripubertal adolescents with obesity, suggesting that such girls are indeed at risk for developing PCOS.

Migration and melanoma incidence rates among Washington state counties.

The purpose of this study was to look for a possible explanation for the variation in the incidence rate of melanoma among counties in Washington state. We used data from the Washington State Cancer Registry (WSCR), the Cancer Center at PeaceHealth St. Joseph Hospital in Whatcom County, and the Surveillance, Epidemiology, and End Results registry to get information on melanoma incidence.

Maximum likelihood estimation of individual inbreeding coefficients and null allele frequencies.

In this paper, we developed and compared several expectation-maximization (EM) algorithms to find maximum likelihood estimates of individual inbreeding coefficients using molecular marker information. The first method estimates the inbreeding coefficient for a single individual and assumes that allele frequencies are known without error. The second method jointly estimates inbreeding coefficients and allele frequencies for a set of individuals that have been genotyped at several loci.

Comparison of marker-based pairwise relatedness estimators on a pedigreed plant population.

Several estimators have been proposed that use molecular marker data to infer the degree of relatedness for pairs of individuals. The objective of this study was to evaluate the performance of seven estimators when applied to marker data of a set of 33 key individuals from a large complex apple pedigree. The evaluation considered different scenarios of allele frequencies and different numbers of marker loci.

One-stage design is empirically more powerful than two-stage design for family-based genome-wide association studies.

Finding a genetic marker associated with a trait is a classic problem in human genetics. Recently, two-stage approaches have gained popularity in marker-trait association studies, in part because researchers hope to reduce the multiple testing problem by testing fewer markers in the final stage. We compared one two-stage family-based approach to an analogous single-stage method, calculating the empirical type I error rates and power for both methods using fully simulated data sets modeled on nuclear families with rheumatoid arthritis, and data sets of real single-nucleotide polymorphism genotypes from Centre d'Etude du Polymorphisme Humain pedigrees with simulated traits.

Linkage disequilibrium in wild mice.

Crosses between laboratory strains of mice provide a powerful way of detecting quantitative trait loci for complex traits related to human disease. Hundreds of these loci have been detected, but only a small number of the underlying causative genes have been identified. The main difficulty is the extensive linkage disequilibrium (LD) in intercross progeny and the slow process of fine-scale mapping by traditional methods.

A maximum-likelihood method for the estimation of pairwise relatedness in structured populations.

A maximum-likelihood estimator for pairwise relatedness is presented for the situation in which the individuals under consideration come from a large outbred subpopulation of the population for which allele frequencies are known. We demonstrate via simulations that a variety of commonly used estimators that do not take this kind of misspecification of allele frequencies into account will systematically overestimate the degree of relatedness between two individuals from a subpopulation. A maximum-likelihood estimator that includes F(ST) as a parameter is introduced with the goal of producing the relatedness estimates that would have been obtained if the subpopulation allele frequencies had been known.

Genetic relatedness analysis: modern data and new challenges.

Individuals who belong to the same family or the same population are related because of their shared ancestry. Population and quantitative genetics theory is built with parameters that describe relatedness, and the estimation of these parameters from genetic markers enables progress in fields as disparate as plant breeding, human disease gene mapping and forensic science. The large number of multiallelic microsatellite loci and biallelic SNPs that are now available have markedly increased the precision with which relationships can be estimated, although they have also revealed unexpected levels of genomic heterogeneity of relationship measures.

Three major haplotypes of the beta2 adrenergic receptor define psychological profile, blood pressure, and the risk for development of a common musculoskeletal pain disorder.

Adrenergic receptor beta(2) (ADRB2) is a primary target for epinephrine. It plays a critical role in mediating physiological and psychological responses to environmental stressors. Thus, functional genetic variants of ADRB2 will be associated with a complex array of psychological and physiological phenotypes.

Measures of human population structure show heterogeneity among genomic regions.

Estimates of genetic population structure (F(ST)) were constructed from all autosomes in two large SNP data sets. The Perlegen data set contains genotypes on approximately 1 million SNPs segregating in all three samples of Americans of African, Asian, and European descent; and the Phase I HapMap data set contains genotypes on approximately 0.6 million SNPs segregating in all four samples from specific Caucasian, Chinese, Japanese, and Yoruba populations.

It was one of my brothers.

When DNA evidence is used to implicate a suspect, it may be of interest to know whether it is likely that the suspect's near relatives also share the suspect's DNA profile. In this study we discuss methods for evaluating the probability that at least one of a set of the suspect's full or half-siblings shares the suspect's DNA profile. We present three such methods: exact calculation, estimation via Monte Carlo simulations, and estimation by means of sandwiching the probability between an upper and a lower bound.

Regional brain responses to serotonin in major depressive disorder.

Background: Positron Emission Tomography (PET) studies have reported altered resting regional brain glucose metabolism in mood disorders. This study examines the relationship of such changes to serotonin system abnormalities associated with depression.

Methods: Thirteen male medication free subjects who were inpatients with a DSM-IIIR major depressive disorder and seven healthy male subjects underwent an [18F]-fluorodeoxyglucose (18FDG) PET scan on consecutive days.