Cultural patterns of trauma among 19th-century-born males in cadaver collections

Comprehending violence among bioarchaeological and historical groups is a topic of recent interest among biological anthropologists. This research examines trauma among African American and Euro-American males of low socioeconomic status born between 1825 and 1877. A total of 651 male skeletons from the Cobb, Terry, and Hamann-Todd anatomical collections were macroscopically evaluated for skeletal trauma, based on the presence of fractures and weapon-related wounds, and statistically analyzed according to ancestry, birth (Antebellum, Civil War, Reconstruction), combined ancestry - birth, and collection cohorts. Results indicated that African Americans and Euro-Americans expressed ethnic differences in regard to interpersonal violence. To interpret these disparities, documentary data were used to reconstruct the socioeconomic and cultural environment of these individuals. This research emphasizes the importance of evaluating skeletal data within the context of class, culture, and environment so that behavioral patterns observed in the skeleton can be better understood.     

Neonatal Variables,Altitude of Residence and Aymara Ancestry in Northern Chile

Studies performed in the Andean plateau, one of the highest inhabited areas in the world, have reported that reduced availability of oxygen is associated to fetal growth retardation and lower birth weight, which are established predictors of morbidity and mortality during the first year of life. To test this hypothesis, perinatal variables of neonates born at the Juan Noé Hospital of Arica, Chile, were analyzed in relation to altitude of residence and Aymara ancestry of their mothers. The study population comprised the offspring of 5,295 mothers born between February 2004 and August 2010. Information included birth weight, height, head circumference, gestational age, altitude of residence and socioeconomic status, and was obtained from medical records. Mother´s ancestry was assessed based on surnames which were linked to percentages of Aymara admixture estimates relying on 40 selected ancestry informative markers. After correcting for the effect of multicollinearity among predictor variables, neonates born to mothers with an increased component of Aymara ancestry showed significantly higher birth weight and height at sea level, a marginally significant (p-value 0.06) decrease of birth weight and a significant decrease of height with altitude in comparison with the offspring of mothers with low Aymara ancestry. Since observed tendencies are suggestive of a possible genetic adaptation to hypoxia of the Chilean Aymara, we discuss briefly preliminary evidence related to fetal oxygen transport, particularly polymorphisms in the promoters of the HBG1 and HBG2 genes that are modulators of HbF synthesis, obtained in this ethnic group.     

Skeletal muscle adiposity is associated with serum lipid and lipoprotein levels in Afro‐Caribbean men

Objective: When compared with other ethnic groups, African ancestry individuals have lower triglycerides and higher High‐density lipoprotein cholesterol (HDL‐C) levels, although the mechanisms for these differences remain unclear. A comprehensive array of factors potentially related to fasting serum lipid and lipoprotein levels in African ancestry men was evaluated. Design and Methods: Men (1,821) underwent dual‐energy X‐ray absorptiometry measures of total body fat and quantitative computed tomography assessments of calf skeletal muscle adiposity [subcutaneous and intermuscular adipose tissue (AT), and muscle density as a measure of intra‐muscular AT]. Results: Multivariable linear regression analysis identified age (?), total body fat (+), subcutaneous AT (?), fasting glucose (+), fasting insulin (+), diastolic blood pressure (+), and non‐African ancestry (+) as independent correlates of triglycerides (all P < 0.05). Total body fat (+), intra‐muscular AT (?), and diastolic blood pressure (+) were independent correlates of Low‐density lipoprotein cholesterol (LDL‐C) (all P < 0.001). Age (+), waist circumference (?), fasting insulin (?), physical activity (+), and alcohol intake (+) were independent correlates of HDL‐C (all P < 0.05). Conclusions: A novel relationship between skeletal muscle adiposity and serum lipid and lipoprotein levels in African ancestry men, independent of total and central adiposity was illuminated. In African ancestry populations, genetic factors are likely a significant determinant of triglycerides levels.     

Skin color comparisons among ethnic groups of college men

Reflectance readings of skin color were taken on the medial aspect of the left upper arm. The subjects were United States college men between ages 18 and 27 years attending the University of South Carolina. Using the DSL 99 Reflectance Spectrophotometer, readings were obtained under controlled conditions at five settings (601, 603, 605, 607, 609). Ethnic groups studied included young men of 1) Northwest European White ancestry, 2) West African Black ancestry, and 3) Afro-Black/Amerind ancestry. Means and variability statistics serve to describe the skin color distributions. Means were near 12 and 32 for filters 601 and 609 on men of West African Black ancestry, with corresponding means near 36 and 64 on men of Northwest European White ancestry. There was no overlapping of comparable frequency distributions from these two ethnic groups. Significance tests at P = .01 allowed acceptance of the hypothesis that skin color on the medial arm surface was darker for young men of Afro-Black ancestry than for those of 75% Afro-Black ancestry and 25% Amerind ancestry. Means from original data were compared with means from earlier studies on black and white males in Africa, America, and Europe.     

Sudden infant death syndrome and postneonatal mortality in immigrants in England and Wales.

To examine ethnic differences in postneonatal mortality and the incidence of sudden infant death in England and Wales during 1982-5 records were analysed, the mother''s country of birth being used to determine ethnic group. Postneonatal mortality was highest in infants of mothers born in Pakistan (6.4/1000 live births) followed by infants of mothers born in the Caribbean (4.5) and the United Kingdom and Republic of Ireland (4.1). Crude rates were lower in infants of mothers born in India (3.9/1000), east and west Africa (3.0), and Bangladesh (2.8) than in infants of mothers born in the United Kingdom despite less favourable birth weights. Mortality ratios standardised separately for maternal age, parity, and social class were significantly higher in infants of mothers born in Pakistan and lower in those of mothers born in Bangladesh. The ratio for infants of Caribbean mothers was significantly higher when adjusted for maternal age. Ratios for infants of Indian and east African mothers did not show significant differences after standardisation. An important finding was a low incidence of sudden infant death in infants of Asian origin. This was paralleled by lower mortality from respiratory causes. During 1975-85 postneonatal mortality in all immigrant groups except Pakistanis fell to a similar or lower rate than that in the United Kingdom group; Pakistanis showed a persistent excess. During 1984-5 several immigrant groups (from the Republic of Ireland, India, west Africa, and the Caribbean) recorded an increase in postneonatal mortality. Surveillance of postneonatal mortality among ethnic communities should be continued, and research is needed to identify the causes underlying the differences.     

Relation of risk of systemic lupus erythematosus to west African admixture in a Caribbean population

Risk of systemic lupus erythematosus (SLE) is higher in people of west African descent than in Europeans. The objective of this study was to distinguish between genetic and environmental explanations for this ethnic difference by examining the relationship of disease risk to individual admixture (defined as the proportion of the genome that is of west African ancestry); 124 cases of SLE and 219 matched controls resident in Trinidad were studied. Analysis of admixture was restricted to 52 cases and 107 controls who reported no Indian or Chinese ancestry. These individuals were typed with a panel of 26 single-nucleotide polymorphisms and five insertion/deletion polymorphisms chosen to have large allele frequency differentials between west African, European and Native American populations. A Bayesian model for population admixture, individual admixture and locus ancestry was fitted by Markov chain simulation. Mean west African admixture (M) was 0.81 in cases and 0.74 in controls (P=0.01). The risk ratio for SLE associated with unit change in M was estimated as 32.5 with a 95% confidence interval (CI) of 2.0-518. Adjustment for measures of socioeconomic status (household amenities in childhood and years of education) altered this risk ratio only slightly (adjusted risk ratio: 28.4, 95% CI 1.7-485). These results support an additive genetic model for the ethnic difference in risk of SLE between west Africans and Europeans, rather than an environmental explanation or an "overdominant" model in which risk is higher in heterozygous than in homozygous individuals. This conclusion lays a basis for localizing the genes underlying this ethnic difference in risk of SLE by admixture mapping.     

African ancestry and its correlation to type 2 diabetes in African Americans: a genetic admixture analysis in three U.S. population cohorts

The risk of type 2 diabetes is approximately 2-fold higher in African Americans than in European Americans even after adjusting for known environmental risk factors, including socioeconomic status (SES), suggesting that genetic factors may explain some of this population difference in disease risk. However, relatively few genetic studies have examined this hypothesis in a large sample of African Americans with and without diabetes. Therefore, we performed an admixture analysis using 2,189 ancestry-informative markers in 7,021 African Americans (2,373 with type 2 diabetes and 4,648 without) from the Atherosclerosis Risk in Communities Study, the Jackson Heart Study, and the Multiethnic Cohort to 1) determine the association of type 2 diabetes and its related quantitative traits with African ancestry controlling for measures of SES and 2) identify genetic loci for type 2 diabetes through a genome-wide admixture mapping scan. The median percentage of African ancestry of diabetic participants was slightly greater than that of non-diabetic participants (study-adjusted difference = 1.6%, P<0.001). The odds ratio for diabetes comparing participants in the highest vs. lowest tertile of African ancestry was 1.33 (95% confidence interval 1.13-1.55), after adjustment for age, sex, study, body mass index (BMI), and SES. Admixture scans identified two potential loci for diabetes at 12p13.31 (LOD = 4.0) and 13q14.3 (Z score = 4.5, P = 6.6 × 10(-6)). In conclusion, genetic ancestry has a significant association with type 2 diabetes above and beyond its association with non-genetic risk factors for type 2 diabetes in African Americans, but no single gene with a major effect is sufficient to explain a large portion of the observed population difference in risk of diabetes. There undoubtedly is a complex interplay among specific genetic loci and non-genetic factors, which may both be associated with overall admixture, leading to the observed ethnic differences in diabetes risk.     

Birth weight in an African-American population living under moderate ecologic stress

The African-American population of McNary, Arizona, resides at an altitude of 2200 m. The lengthy winters are typically quite cold; the monthly mean temperature from November to April is 1.8 degrees C. Data from 318 singleton full-term births of African-American babies from 1949 to 1972 show a mean weight of 3095 g (s.d. = 427 g). At birth 1.9% of the babies weighed at least 4 kg; 9.7% weighed less than 2.5 kg. These data suggest that altitude may have influenced birth weight in this sample. Significant patterns in birth weight exist for sex, parity, mother's age, and severity of the winter preceding the year of birth. The birth weight of female babies born following warm winters is significantly lighter than those born during years following cold winters. There are relatively fewer high-birth-weight babies, in comparison to other African-American populations. Birth weight is also significantly lighter than three other African-American samples, even though African-American mothers of McNary had full-term professional care. Birth weight of African-American babies born in McNary is consistent with the overwhelming African ancestry of the African-American population of McNary. Sex differences in birth weight of babies born following cold winters can be ascribed to gender-related hereditary or physiologic factors at the level of the fetus. Maternal inactivity during particularly cold winters may be a contributing factor.     

Association of serum lipid components and obesity with genetic ancestry in an admixed population of elderly women

The prevalence of metabolic disorders varies among ethnic populations and these disorders represent a critical health care issue for elderly women. This study investigated the correlation between genetic ancestry and body composition, metabolic traits and clinical status in a sample of elderly women. Clinical, nutritional and anthropometric data were collected from 176 volunteers. Genetic ancestry was estimated using 23 ancestry-informative markers. Pearsons correlation test was used to examine the relationship between continuous variables and an independent samples t-test was used to compare the means of continuous traits within categorical variables. Overall ancestry was a combination of European (57.49%), Native American (25.78%) and African (16.73%). Significant correlations were found for European ancestry with body mass index (r = 0.165; p = 0.037) and obesity (mean difference (MD) = 5.3%; p = 0.042). African ancestry showed a significant correlation with LDL (r = 0.159, p = 0.035), VLDL (r = −0.185; p = 0.014), hypertriglyceridemia (MD = 6.4%; p = 0.003) and hyperlipidemia (MD = 4.8%; p = 0.026). Amerindian ancestry showed a significant correlation with triglyceride levels (r = 0.150; p = 0.047) and hypertriglyceridemia (MD = 4.5%; p = 0.039). These findings suggest that genetic admixture may influence the etiology of lipid metabolism-related diseases and obesity in elderly women.     

Associations of SNPs in ADIPOQ and subclinical cardiovascular disease in the multi-ethnic study of atherosclerosis (MESA)

Circulating adiponectin is associated with both clinical and subclinical cardiovascular disease (CVD). Variants of the adiponectin gene (ADIPOQ) are associated with clinical CVD, but little is known about associations with subclinical CVD. We studied the association of 11 ADIPOQ single-nucleotide polymorphisms (SNPs) with common and internal carotid intima media thickness (cIMT), presence of coronary artery calcification (CAC), and CAC scores (in those with CAC) in 2,847 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Participants were white (n = 712), African American (n = 712), Chinese (n = 718), and Hispanic (n = 705). All models were adjusted for age, sex, and field site, and stratified by race/ethnic group. African Americans with genotypes AG/GG of rs2241767 had 36% greater (95% confidence interval (CI; 16%, 59%), P = 0.0001) CAC prevalence; they also had a larger common cIMT (P = 0.0043). Also in African Americans, genotypes AG/AA of rs1063537 were associated with a 35% (95% CI (14%, 59%), P = 0.0005) greater CAC prevalence. Hispanics with the AA genotype of rs11711353 had a 37% (95% CI (14%, 66%), P = 0.0011), greater CAC prevalence compared to those with the GG genotype. Additional adjustment for ancestry in African-American and Hispanic participants did not change the results. No single SNP was associated with subclinical CVD phenotypes in Chinese or white participants. There appears to be an association between ADIPOQ SNPs and subclinical CVD in African Americans and Hispanics. Replication as well as assessment of other ADIPOQ SNPs is warranted.     

Gastroschisis, low maternal age, and fetal morbidity outcomes

OBJECTIVE: To determine if the risk for fetal growth inhibition among gastroschisis-afflicted fetuses is heightened among younger gravidas (teen mothers). METHOD: This was a retrospective cohort study on live-born infants with isolated gastroschisis delivered in New York State from 1983 through 1999. We compared infants of mature (>20 years) mothers with those of younger (<20 years) mothers with respect to the following indices of fetal morbidity outcomes: low birth weight and very low birth weight, preterm and very pre-term, and small for gestational age. We used adjusted odds ratios to approximate relative risks. RESULTS: A total of 368 infants with isolated gastroschisis were analyzed. The two groups differed in terms of mean gestational age at delivery [Mean + standard deviation(SD) for infants with gastroschisis born to mature mothers = 37.2 weeks +/- 2.8 versus 36.3 weeks + 3.6 for those of teenage mothers(p = 0.01)], as well as mean birth weight [mean birth weight +/- SD for infants with gastroschisis born to mature mothers = 2562.4 grams +548.8 versus 2367.9 grams +/- 645.2 for those of younger mothers (p = 0.004)]. Infants of teen mothers were about twice as likely to be of low birth weight (OR = 1.70; 95% CI = 1.05-2.77) and about three times as likely to be born very preterm when compared to those of mature mothers (OR = 2.80; 95% Cl = 1.02-8.00). No significant differences were observed with respect to very low birth weight, pre-term and small for gestational age. CONCLUSION: Low maternal age appears to be a risk factor for low birth weight and very preterm birth among gastroschisis-affected fetuses. This information is potentially useful for planning by care providers and in counseling affected parents.     

Analysis of susceptibility polymorphisms for nonsyndromic cleft lip with or without cleft palate in the Brazilian population

Background : Although genome‐wide association studies have identified several susceptibility loci for nonsyndromic cleft lip with or without cleft palate (NSCL/P) in populations around the world, the role of most loci is unknown in the highly heterogeneous Brazilian population. Methods : To determine the association of 7 markers that showed genome‐wide significant association in Brazilians with NSCL/P, we conducted a structured association study conditioned upon the individual ancestry proportions to evaluate markers at 1p36 (rs742071), 2p21 (rs7590268), 3p11.1 (rs7632427), 8q21.3 (rs12543318), 13q31.1 (rs8001641), 15q22.2 (rs1873147), and 17q22 (rs227731) in 505 patients with NSCL/P and 594 healthy controls recruited from 2 different geographical regions of Brazil. The polymorphisms were genotyped by TaqMan 5′‐exonuclease allelic discrimination assay, and each sample was independently typed for 40 biallelic short insertion/deletion markers to characterize the genomic ancestry. Results : After Bonferroni correction for multiple tests, significant associations with NSCL/P were observed for rs742071, rs1873147, and rs227731. However, the frequency of the risk alleles varied between the geographical regions, according to the proportions of European and African genomic ancestry. The group enriched by European ancestry showed significant association with rs227731 (p = 0.001), whereas the group with high African ancestry was significantly associated with rs1873147 polymorphism (p = 0.005). The significant association with rs742071 was only detected in the combined sample (p = 0.005). Conclusion : The findings of the present study revealed the associations of 1p36 (rs742071), 15q22 (rs1873147), and 17p22 (rs227731) with NSCL/P in the Brazilian population, and further confirmed that the genetic heterogeneity of NSCL/P may be related to the different ethnic background of the affected individuals. Birth Defects Research (Part A) 100:36–42, 2014. © 2013 Wiley Periodicals, Inc.     

Association of the CPT1B Gene with Skeletal Muscle Fat Infiltration in Afro‐Caribbean Men

Skeletal muscle fat is greater in African ancestry individuals compared with whites, is associated with diabetes, and is a heritable polygenic trait. However, specific genetic factors contributing to skeletal muscle fat in humans remain to be defined. Muscle carnitine palmitoyltransferase‐1B (CPT1B) is a key enzyme in the regulation of skeletal muscle mitochondrial β‐oxidation of long‐chain fatty acids, and as such is a reasonable biological candidate gene for skeletal muscle fat accumulation. Therefore, we examined the association of three nonsynonymous coding variants in CPT1B (G531L, I66V, and S427C; a fourth, A320G, could not be genotyped) and quantitative computed tomography measured tibia skeletal muscle composition and BMI among 1,774 Afro‐Caribbean men aged ≥40, participants of the population‐based Tobago Health Study. For all variants, no significant differences were observed for BMI or total adipose tissue. Among individuals who were homozygous for the minor allele at G531L or I66V, intermuscular adipose tissue (IMAT) was 87% (P = 0.03) and 54% lower (P = 0.03), respectively. In contrast, subcutaneous adipose tissue (SAT) was 11% (P = 0.017) and 7% (P = 0.049) higher, respectively, than among individuals without these genotypes. These associations were independent of age, body size, and muscle area. Finally, no individuals with type 2 diabetes were found among those who were homozygous for the minor allele of either at G531L and I66V whereas 14–18% of men with the major alleles had type 2 diabetes (P = 0.03 and 0.007, respectively). Our results suggest a novel association between common nonsynonymous coding variants in CPT1B and ectopic skeletal muscle fat among middle‐aged and older African ancestry men.     

Ethnic Variation in Inflammatory Profile in Tuberculosis

Distinct phylogenetic lineages of Mycobacterium tuberculosis (MTB) cause disease in patients of particular genetic ancestry, and elicit different patterns of cytokine and chemokine secretion when cultured with human macrophages in vitro. Circulating and antigen-stimulated concentrations of these inflammatory mediators might therefore be expected to vary significantly between tuberculosis patients of different ethnic origin. Studies to characterise such variation, and to determine whether it relates to host or bacillary factors, have not been conducted. We therefore compared circulating and antigen-stimulated concentrations of 43 inflammatory mediators and 14 haematological parameters (inflammatory profile) in 45 pulmonary tuberculosis patients of African ancestry vs. 83 patients of Eurasian ancestry in London, UK, and investigated the influence of bacillary and host genotype on these profiles. Despite having similar demographic and clinical characteristics, patients of differing ancestry exhibited distinct inflammatory profiles at presentation: those of African ancestry had lower neutrophil counts, lower serum concentrations of CCL2, CCL11 and vitamin D binding protein (DBP) but higher serum CCL5 concentrations and higher antigen-stimulated IL-1 receptor antagonist and IL-12 secretion. These differences associated with ethnic variation in host DBP genotype, but not with ethnic variation in MTB strain. Ethnic differences in inflammatory profile became more marked following initiation of antimicrobial therapy, and immunological correlates of speed of elimination of MTB from the sputum differed between patients of African vs. Eurasian ancestry. Our study demonstrates a hitherto unappreciated degree of ethnic heterogeneity in inflammatory profile in tuberculosis patients that associates primarily with ethnic variation in host, rather than bacillary, genotype. Candidate immunodiagnostics and immunological biomarkers of response to antimicrobial therapy should be derived and validated in tuberculosis patients of different ethnic origin.     

Influences of month of birth and age on patterns of luteinizing hormone secretion in prepubertal heifers

An experiment was done to determine if month of birth and age influenced patterns of luteinizing hormone (LH) secretion in prepubertal heifers. Mean concentrations of LH increased linearly (P < .05) in March-born heifers between one and seven months of age. This was partially due to an increase in number of LH pulses. The prepubertal pattern of LH concentrations was quadratic (P < .05) for heifers born in September because concentrations were slightly higher (P = .15) than those in March-born heifers at one month of age. There were no differences between groups during the remainder of the prepubertal period (3 to 7 months). There was a tendency (P = .18) for September-born animals to reach puberty at younger ages than those born in March. September-born heifers also had greater (P = .06) average daily gains, but body weights at puberty were similar for the two groups. These results show that season of birth influenced LH concentrations at one month of age, but did not significantly affect the increase between three and seven months of age.     

Birth, morphologic, and blood characteristics of free-ranging white-tailed deer neonates

Winter severity is a primary factor influencing deer survival and reproduction in northern climates. Prolonged, harsh winters can adversely affect body condition of does, resulting in depressed morphologic development of neonates. In this study, we captured 59 white-tailed deer (Odocoileus virginianus) neonates (28 in 2001 and 31 in 2002), following two distinctly different winters, one severe and the other historically mild. Vaginal implant transmitters allowed exact age to be determined for 73% of the neonates; new hoof growth was used to estimate age (days) of the other 27%. Birthdate and morphologic measurements of neonates (i.e., birth mass, new hoof growth, hoof length) were compared by sex and capture year. For known-age neonates (n=43), there was a year-by-sex interaction effect (P=0.01) on birthdate, being later for females during spring 2001 compared with 2002, which was consistent with a significant (P=0.03) year-by-sex interaction for total hoof length (22.3 mm [SE=0.9] and 20.3 [SE=0.8] for females and males in 2001; 19.9 [SE=1.0] and 22.1 [SE=1.0] for females and males in 2002). Interestingly, there was no effect of year on birth mass or birthdate of known-age neonates. A year-by-sex interaction (P=0.04) was determined for birthdates of estimated age (5 yr old were born later (P<0.01) than fawns born to dams 相似文献   

Amerindian (but not African or European) ancestry is significantly associated with diurnal preference within an admixed Brazilian population

Significant questions remain unanswered regarding the genetic versus environmental contributions to racial/ethnic differences in sleep and circadian rhythms. We addressed this question by investigating the association between diurnal preference, using the morningness–eveningness questionnaire (MEQ), and genetic ancestry within the Baependi Heart Study cohort, a highly admixed Brazilian population based in a rural town. Analysis was performed using measures of ancestry, using the Admixture program, and MEQ from 1,453 individuals. We found an association between the degree of Amerindian (but not European of African) ancestry and morningness, equating to 0.16 units for each additional percent of Amerindian ancestry, after adjustment for age, sex, education, and residential zone. To our knowledge, this is the first published report identifying an association between genetic ancestry and MEQ, and above all, the first one based on ancestral contributions within individuals living in the same community. This previously unknown ancestral dimension of diurnal preference suggests a stratification between racial/ethnic groups in an as yet unknown number of genetic polymorphisms.     

West African and Amerindian ancestry and risk of myocardial infarction and metabolic syndrome in the Central Valley population of Costa Rica

Genetic ancestry and environmental factors may contribute to the ethnic differences in risk of coronary heart disease (CHD), metabolic syndrome (MS) or its individual components. The population of the Central Valley of Costa Rica offers a unique opportunity to assess the role of genetic ancestry in these chronic diseases because it derived from the admixture of a relatively small number of founders of Southern European, Amerindian, and West African origin. We aimed to determine whether genetic ancestry is associated with risk of myocardial infarction (MI), MS and its individual components in the Central Valley of Costa Rica. We genotyped 39 ancestral informative markers in cases (n = 1,998) with a first non-fatal acute MI and population-based controls (n = 1,998) matched for age, sex, and area of residence, to estimate individual ancestry proportions. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using conditional (MI) and unconditional (MS and its components) logistic regression adjusting for relevant confounders. Mean individual ancestry proportions in cases and controls were 57.5 versus 57.8% for the Southern European, 38.4 versus 38.3% for the Amerindian and 4.1 versus 3.8% for the West African ancestry. Compared with Southern European ancestry, each 10% increase in West African ancestry was associated with a 29% increase in MI, OR (95% CI) = 1.29 (1.07, 1.56), and with a 30% increase on the risk of hypertension, OR (95% CI) = 1.30 (1.00, 1.70). Each 10% increase in Amerindian ancestry was associated with a 14% increase on the risk of MS, OR (95% CI) = 1.14 (1.00, 1.30), and 20% increase on the risk of impaired fasting glucose, OR (95% CI) = 1.20 (1.01, 1.42). These results show that the high variability of admixture proportions in the Central Valley population offers a unique opportunity to uncover the genetic basis of ethnic differences on the risk of disease.     

Differences in maternal age-specific rates of Down syndrome between Jews of European origin and of North African or Asian origin.

Rates of Down syndrome in livebirths in West Jerusalem in 1964-1975 were studied in relation to the mother's continent of birth or, if she was born in Israel, to the maternal grandfather's continent of birth. In women of European origin the crude livebirth rate of Down syndrome was 1.3 per 1,000 livebirths. This crude rate and the maternal age-specific rates in this group were very close to those observed in a Swedish study and two studies of white livebirths in the United States. For West Jerusalem women of North African or Asian origin the crude rate was about 2.4 per 1,000 livebirths, and at all maternal ages except the youngest their rates were higher than for women of European origin. The summary adjusted relative risk for a Down syndrome livebirth for all those of North African or Asian origin, compared to those for women of European origin, was about 1.56. If attention is restricted to mothers born outside of Israel, the adjusted relative risk for mothers born in Europe, the Americas or English speaking countries of the British commonwealth compared to those born in North Africa or Asia was 1.97, consistent with a two-fold difference in the likelihood of a Down syndrome livebirth between thes two groups. To our knowledge this is the first report of ethnic differences in maternal age specific rates of Down syndrome that cannot be plausibly explained by differences in ascertainment.     

Examination of ancestry and ethnic affiliation using highly informative diallelic DNA markers: application to diverse and admixed populations and implications for clinical epidemiology and forensic medicine

We and others have identified several hundred ancestry informative markers (AIMs) with large allele frequency differences between different major ancestral groups. For this study, a panel of 199 widely distributed AIMs was used to examine a diverse set of 796 DNA samples including self-identified European Americans, West Africans, East Asians, Amerindians, African Americans, Mexicans, Mexican Americans, Puerto Ricans and South Asians. Analysis using a Bayesian clustering algorithm (STRUCTURE) showed grouping of individuals with similar ethnic identity without any identifier other than the AIMs genotyping and showed admixture proportions that clearly distinguished different individuals of mixed ancestry. Additional analyses showed that, for the majority of samples, the predicted ethnic identity corresponded with the self-identified ethnicity at high probability (P > 0.99). Overall, the study demonstrates that AIMs can provide a useful adjunct to forensic medicine, pharmacogenomics and disease studies in which major ancestry or ethnic affiliation might be linked to specific outcomes.Electronic Supplementary Material Supplementary material is available for this article at