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A study uses a weighted false discovery rate control procedure to detect low-frequency variations in association with fasting glucose levels in European American populations. Results obtained using the Affymetric Genome-Wide SNP Array 6.0 reveal a low-frequency allele near FOXA2 gene that influence fasting glucose levels in European Americans.

The C4 gene copy-number variation (CNV) was investigated in 1241 European Americans, including patients with systemic lupus erythematosus (SLE), their first degree relatives by defining genotyping and phenotyping techniques. The results show that gene copy number of gene CNV provides data for an important immune defense protein in health and disease suggesting that low copy number is a risk factor for and high copy number is a protective factor against susceptibility to human SLE.

The African American (AA) gene pool is primarily the result of gene flow between two biologically disparate groups: West Africans (WA) and Americans of western European descent (EA). This research utilizes characteristics of dental morphology to trace genetic relationships among WA, western Europeans (EU), AA, and European Americans. Dental morphological traits are useful for this purpose because they are heritable, do not remodel during life (although they can be lost to wear or pathology), and can be compared equally among samples from past and present populations. The results of this research provide new information about human microevolution through time and space in a biocultural setting. The mean measure of divergence is used to analyze dental morphological data from 1,265 individuals in 25 samples grouped by ancestry and time. Three hypotheses associated with admixture in AA are tested. When compared with known history, results from dental morphological data are equivocal in documenting admixture in AA. Dental morphological traits do appear to reflect admixture in AA. However, changes in trait frequencies do not closely correspond with important cultural events and trends such as the institutionalized racism of the Civil War and Jim Crow era. Results are mixed concerning whether AA with greater admixture were more likely to take part in the Great Migration to southern urban centers and to the North. KEY WORDS dentition; European Americans; admixture; African Americans

Estimates of coverage based on standard linkage-disequilibrium measures, such as the average maximum squared correlation coefficient (r(super 2)), can lead to inaccurate and inflated estimates of the power of genomewide association studies. But, use of the 'cumulative r(super 2) adjusted power' measure presented here gives more-accurate estimates of power for genomewide association studies.

Balasubramanyam, Ashok, Siripoom McKay, Prashant Nadkarni, Arun S. Rajan, Armandina Garza, Valory Pavlik, J. Alan Herd, Farook Jahoor, and Peter J. Reeds. Ethnicity affects the postprandial regulation of glycogenolysis. Am. J. Physiol. 277 (Endocrinol. Metab. 40): E905-E914, 1999.--We investigated the effect of nutrient intake on glucose metabolism in normal Mexican-Americans (n = 6) and European-Americans (n = 6). Subjects were studied after an 18-h fast and after 5-6 h of ingestion of hourly meals that supplied 6.35 or 12.75 [micro]mol glucose, [kg.sup.-1] [multiplied by] [min.sup.-1]. Endogenous glucose production (EGP), gluconeogenesis (GNG), and glycogenolysis (GLY) were estimated by mass isotopomer analysis with [U-[sup.13]C]glucose infusions. Fasting EGP, GNG, and GLY did not differ between the groups. Food ingestion lowered the molar rate of GNG by only 31%. However, while consuming the lower quantity of nutrients, Mexican-Americans had higher plasma glucose (P [is less than] 0.05), a 39% higher rate of EGP (P [is less than]0.05), and a 68% (P [is less than] 0.025) higher rate of GLY than the European-Americans. At the higher intake, EGP and GLY were suppressed completely in both groups. There was a linear relationship between insulin concentrations, EGP, and GLY in both groups, but the slope of the line was significantly (P [is less than] 0.05) greater in the European-Americans. We conclude that the sensitivity of GLY to nutrient intake differs between ethnic groups and that this may play a role in the increased predisposition of Mexican-Americans to type II diabetes. Mexican-American; type II diabetes; gluconeogenesis