Home About us Contact
|
Home About us Contact | ||
|
|
||
Mixed Ancestry (mixed + ancestry)
Selected AbstractsDNA Sequence Characterization of the FGA STR Locus in the Free State Population of South AfricaJOURNAL OF FORENSIC SCIENCES, Issue 1 2006André de Kock Ph.D. POPULATION: African (n=52), Mixed Ancestry (n=5), Caucasian (n=4) SAN (n=1). [source] Neuropsychiatric movement disorders following streptococcal infectionDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2005K G Walker MB BS The aim of this study was to describe post-streptococcal movement disorders that form part of the acute rheumatic fever complex. The clinical records of patients diagnosed with Sydenham's chorea were analyzed retrospectively to investigate epidemiology, the significance of socioeconomic deprivation, clinical manifestations, treatments, outcomes, long-term morbidity, and disease evolution. Forty-two patients (21 males, 21 females) were diagnosed with Sydenham's chorea. The median presentation age was 9 years 8 months (range 3y 5mo to 13y 2mo). Nineteen patients were of indigenous African ancestry; 23 were of mixed ancestry. All patients lived in poverty and had poor access to medical care. Twelve of the total group had disabling symptoms for longer than 2 years; six of these patients developed paediatric autoimmune neuropsychiatric disorder associated with Streptococcus (Paediatric autoimmune neuropsychiatric disorder associated with Streptococcus [PANDAS]), five Tourette syndrome (TS), and one learning difficulties. Poor outcome was significantly more prevalent in patients of mixed ancestry, in those with a positive family history, previous behavioural problems, or a failure to complete 10 days of penicillin and ,bed-rest'/hospitalization. Sydenham's chorea is one manifestation of post-streptococcal neuropsychiatric movement disorders. This study demonstrates that patients can present with one diagnosis and evolve other neuropsychiatric conditions such as TS and PANDAS. In the South African context, it is important to delineate neuropsychiatric movement disorders associated with streptococcal infections. The potential genetic susceptibility should be explored. [source] MULTILOCUS ANALYSES OF ADMIXTURE AND INTROGRESSION AMONG HYBRIDIZING HELICONIUS BUTTERFLIESEVOLUTION, Issue 6 2006Marcus R. Kronforst Abstract Introgressive hybridization is an important evolutionary process and new analytical methods provide substantial power to detect and quantify it. In this study we use variation in the frequency of 657 AFLP fragments and DNA sequence variation from 15 genes to measure the extent of admixture and the direction of interspecific gene flow among three Heliconius butterfly species that diverged recently as a result of natural selection for Müllerian mimicry, and which continue to hybridize. Bayesian clustering based on AFLP genotypes correctly delineated the three species and identified four H. cydno, three H. pachinus, and three H. melpomene individuals that were of mixed ancestry. Gene genealogies revealed substantial shared DNA sequence variation among all three species and coalescent simulations based on the Isolation with Migration (IM) model pointed to interspecific gene flow as its cause. The IM simulations further indicated that interspecific gene flow was significantly asymmetrical, with greater gene flow from H. pachinus into H. cydno (2Nm 5 4.326) than the reverse (2Nm 5 0.502), and unidirectional gene flow from H. cydno and H. pachinus into H. melpomene (2Nm 5 0.294 and 0.252, respectively). These asymmetries are in the directions expected based on the genetics of wing patterning and the probability that hybrids of various phenotypes will survive and reproduce in different mimetic environments. This empirical demonstration of extensive interspecific gene flow is in contrast to a previous study which found little evidence of gene flow between another pair of hybridizing Heliconius species, H. himera and H. erato, and it highlights the critical role of natural selection in maintaining species diversity. Furthermore, these results lend support to the hypotheses that phenotypic diversification in the genus Heliconius has been fueled by introgressive hybridization and that reinforcement has driven the evolution of assortative mate preferences. [source] Establishing an oral anticoagulant monitoring service in a multiethnic developing countryINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2008T. CASIMIRE Summary We describe the establishment of an International Normalized Ratio (INR)-based system for monitoring oral anticoagulant therapy in a multiethnic developing country. There was significant variation in geometric mean normal prothrombin time among ethnic groups: 12.7 s for Indians, 13.4 s for Africans and 13.7 s for subjects of mixed ancestry. About 4129 INR measurements were performed in the first 2 years. The majority (55.2%) of achieved INRs were subtherapeutic. We found 31 (0.8%) instances of severe overanticoagulation (INR > 8.0). There were no bleeding manifestations in 24 (77%) of them. Only two experienced life-threatening haemorrhage. The management of bleeding and excessive anticoagulation was not always in accordance with international recommendations. The high incidence of underanticoagulation in Trinidad and Tobago may be due to genetically determined warfarin resistance or underdosing. Oral anticoagulant monitoring in Trinidad and Tobago could benefit from the centralization of such services to designated clinics with specialized staff and computer-assisted dosing which adopt internationally accepted guidelines for practice. [source] An fMRI Study of Number Processing in Children With Fetal Alcohol SyndromeALCOHOLISM, Issue 8 2010Ernesta M. Meintjes Background:, Number processing deficits are frequently seen in children exposed to alcohol in utero. Methods:, Functional magnetic resonance imaging was used to examine the neural correlates of number processing in 15 right-handed, 8- to 12-year-old children diagnosed with fetal alcohol syndrome (FAS) or partial FAS (PFAS) and 18 right-handed, age- and gender-matched controls from the Cape Coloured (mixed ancestry) community in Cape Town, South Africa, using Proximity Judgment and Exact Addition tasks. Results:, Control children activated the expected fronto-parietal network during both tasks, including the anterior horizontal intraparietal sulcus (HIPS), left posterior HIPS, left precentral sulcus, and posterior medial frontal cortex. By contrast, on the Proximity Judgment task, the exposed children recruited additional parietal pathways involving the right and left angular gyrus and posterior cingulate/precuneus, which may entail verbally mediated recitation of numbers and/or subtraction to assess relative numerical distances. During Exact Addition, the exposed children exhibited more diffuse and widespread activations, including the cerebellar vermis and cortex, which have been found to be activated in adults engaged in particularly challenging number processing problems. Conclusions:, The data suggest that, whereas control children rely primarily on the fronto-parietal network identified in previous studies to mediate number processing, children with FAS/PFAS recruit a broader range of brain regions to perform these relatively simple number processing tasks. Our results are consistent with structural neuroimaging findings indicating that the parietal lobe is relatively more affected by prenatal alcohol exposure and provide the first evidence for brain activation abnormalities during number processing in children with FAS/PFAS, effects that persist even after controlling statistically for group differences in total intracranial volume and IQ. [source] Prenatal Alcohol Exposure Alters Biobehavioral Reactivity to Pain in NewbornsALCOHOLISM, Issue 4 2010Tim F. Oberlander Objectives:, To examine biobehavioral responses to an acute pain event in a Cape Town, South Africa, cohort consisting of 28 Cape Colored (mixed ancestry) newborns (n = 14) heavily exposed to alcohol during pregnancy (exposed), and born to abstainers (n = 14) or light (,0.5 oz absolute alcohol/d) drinkers (controls). Methods:, Mothers were recruited during the third trimester of pregnancy. Newborn data were collected on postpartum day 3 in the maternity obstetrical unit where the infant had been delivered. Heavy prenatal alcohol exposure was defined as maternal consumption of at least 14 drinks/wk or at least 1 incident of binge drinking/mo. Acute stress-related biobehavioral markers [salivary cortisol, heart rate (HR), respiratory sinus arrhythmia (RSA), spectral measures of heart rate variability (HRV), and videotaped facial actions] were collected thrice during a heel lance blood collection (baseline, lance, and recovery). After a feeding and nap, newborns were administered an abbreviated Brazelton Neonatal Behavioral Assessment Scale. Results:, There were no between-group differences in maternal age, marital status, parity, gravidity, depression, anxiety, pregnancy smoking, maternal education, or infant gestational age at birth (all ps > 0.15). In both groups, HR increased with the heel lance and decreased during the postlance period. The alcohol-exposed group had lower mean HR than controls throughout, and showed no change in RSA over time. Cortisol levels showed no change over time in controls but decreased over time in exposed infants. Although facial action analyses revealed no group differences in response to the heel lance, behavioral responses assessed on the Brazelton Neonatal Scale showed less arousal in the exposed group. Conclusions:, Both cardiac autonomic and hypothalamic,pituitary,adrenal stress reactivity measures suggest a blunted response to an acute noxious event in alcohol-exposed newborns. This is supported by results on the Brazelton Neonatal Scale indicating reduced behavioral arousal in the exposed group. To our knowledge, these data provide the first biobehavioral examination of early pain reactivity in alcohol-exposed newborns and have important implications for understanding neuro-/biobehavioral effects of prenatal alcohol exposure in the newborn period. [source] A South African mixed ancestry family with Huntington disease-like 2: Clinical and genetic featuresMOVEMENT DISORDERS, Issue 14 2007Soraya Bardien PhD Abstract Huntington disease-like 2 (HDL2) is a neurodegenerative disorder caused by an expansion of a CTG repeat in the junctophilin-3 gene (JPH3). A limited number of HDL2 families have been reported, all of apparently Black African ancestry. We report on a South African family that presented with progressive dementia and a movement disorder affecting numerous family members. Genotyping of the JPH3 CTG repeat revealed pathogenic expansions in three affected individuals. Whereas HDL2 is thought to be clinically indistinguishable from Huntington disease (HD), 2 of the patients in this study presented with clinical symptoms that differed substantially from HD; one had myoclonus and the other had Parkinsonism. Moreover, brain magnetic resonance imaging scans of these patients showed imaging features atypical for HD. Mitochondrial DNA and Y-chromosome DNA analysis on a family member showed that his maternal and paternal ancestries are typical of that found among the South African mixed ancestry or colored population. A difference in the distribution of CTG repeats between Caucasian and Black individuals was detected. We conclude that the phenotype of HDL2 is broad and can differ from that of typical HD. The diagnosis therefore should be considered in a wide spectrum of neuropsychiatric and abnormal movement presentations. © 2007 Movement Disorder Society [source] Childhood cancer in relation to parental race and ethnicityCANCER, Issue 12 2010A 5-state pooled analysis Abstract BACKGROUND: Children of different racial/ethnic backgrounds have varying risks of cancer. However, to the authors' knowledge, few studies to date have examined cancer occurrence in children of mixed ancestry. METHODS: This population-based case-control study examined cancer among children aged <15 years using linked cancer and birth registry data from 5 US states from 1978 through 2004. Data were available for 13,249 cancer cases and 36,996 controls selected from birth records. Parental race/ethnicity was determined from birth records. Logistic regression analysis was used to examine the association of cancer with different racial/ethnic groups. RESULTS: Compared with whites, blacks had a 28% decreased risk of cancer (odds ratio [OR], 0.72; 95% confidence interval [95% CI], 0.65-0.80), whereas both Asians and Hispanics had an approximate 15% decrease. Children of mixed white/black ancestry also were found to be at decreased risk (OR, 0.71; 95% CI, 0.56-0.90), but estimates for mixed white/Asian and white/Hispanic children did not differ from those of whites. Compared with whites: 1) black and mixed white/black children had decreased ORs for acute lymphoblastic leukemia (OR, 0.39 [95% CI, 0.31-0.49] and OR, 0.58 [95% CI, 0.37-0.91], respectively); 2) Asian and mixed white/Asian children had decreased ORs for brain tumors (OR, 0.51 [95% CI, 0.39-0.68] and OR, 0.79 [95% CI, 0.54-1.16], respectively); and 3) Hispanic and mixed white/Hispanic children had decreased ORs for neuroblastoma (OR, 0.51 [95% CI, 0.42-0.61] and OR, 0.67 [95% CI, 0.50-0.90], respectively). CONCLUSIONS: Children of mixed ancestry tend to have disease risks that are more similar to those of racial/ethnic minority children than the white majority group. This tendency may help formulate etiologic studies designed to study possible genetic and environmental differences more directly. Cancer 2010. © 2010 American Cancer Society. [source] | ||||||||||