Mixed Race Studies

Mapping genes that predict treatment outcome in admixed populations

The Pharmacogenomics Journal
Published Online: 2010-10-05
DOI: 10.1038/tpj.2010.71

Tesfaye Mersha Baye, Assistant Professor
University of Cincinnati College of Medicine

Russell Alan Wilke, Associate Professor of Medicine
Vanderbilt University Medical Center

There is great interest in characterizing the genetic architecture underlying drug response. For many drugs, gene-based dosing models explain a considerable amount of the overall variation in treatment outcome. As such, prescription drug labels are increasingly being modified to contain pharmacogenetic information. Genetic data must, however, be interpreted within the context of relevant clinical covariates. Even the most predictive models improve with the addition of data related to biogeographical ancestry. The current review explores analytical strategies that leverage population structure to more fully characterize genetic determinants of outcome in large clinical practice-based cohorts. The success of this approach will depend upon several key factors: (1) the availability of outcome data from groups of admixed individuals (that is, populations recombined over multiple generations), (2) a measurable difference in treatment outcome (that is, efficacy and toxicity end points), and (3) a measurable difference in allele frequency between the ancestral populations.

Africans in Yorkshire? The deepest-rooting clade of the Y phylogeny within an English genealogy

European Journal of Human Genetics
Volume 15 (2007)
pages 288–293
DOI: 10.1038/sj.ejhg.5201771

Turi E. King
University of Leicester

Emma J. Parkin
University of Leicester

Geoff Swinfield
Geoff Swinfield Genealogical Services, Mottingham, London

Fulvio Cruciani
Università degli Studi di Roma ‘La Sapienza’

Rosaria Scozzari
Università degli Studi di Roma ‘La Sapienza’

Alexandra Rosa
Università degli Studi di Roma ‘La Sapienza’

Si-Keun Lim
Wellcome Trust Sanger Institute, Hinxton, United Kingdom

Yali Xue
Wellcome Trust Sanger Institute, Hinxton, United Kingdom

Chris Tyler-Smith
Wellcome Trust Sanger Institute, Hinxton, United Kingdom

Mark A. Jobling
University of Leicester

The presence of Africans in Britain has been recorded since Roman times, but has left no apparent genetic trace among modern inhabitants. Y chromosomes belonging to the deepest-rooting clade of the Y phylogeny, haplogroup (hg) A, are regarded as African-specific, and no examples have been reported from Britain or elsewhere in Western Europe. We describe the presence of an hgA1 chromosome in an indigenous British male; comparison with African examples suggests a Western African origin. Seven out of 18 men carrying the same rare east-Yorkshire surname as the original male also carry hgA1 chromosomes, and documentary research resolves them into two genealogies with most-recent-common-ancestors living in Yorkshire in the late 18th century. Analysis using 77 Y-short tandem repeats (STRs) is consistent with coalescence a few generations earlier. Our findings represent the first genetic evidence of Africans among ‘indigenous’ British, and emphasize the complexity of human migration history as well as the pitfalls of assigning geographical origin from Y-chromosomal haplotypes.

Introduction

The population of the UK today is culturally diverse, with 8% of its 54 million inhabitants belonging to ethnic minorities, and over one million classifying themselves as ‘Black or Black British’ in the 2001 census. These people owe their origins to immigration from the Caribbean and Africa beginning in the mid-20th century; before this time, the population has been seen as typically Western European, and its history has been interpreted in terms of more local immigration, including that of the Saxons, Vikings and Normans. However, in reality, Britain has a long history of contact with Africa (reviewed by Fryer). Africans were first recorded in the north 1800 years ago, as Roman soldiers defending Hadrian’s wall –‘a division of Moors’. Some historians suggest that Vikings brought captured North Africans to Britain in the 9th century. After a hiatus of several hundred years, the influence of the Atlantic slave trade began to be felt, with the first group of West Africans being brought to Britain in 1555. African domestic servants, musicians, entertainers and slaves then became common in the Tudor period, prompting an unsuccessful attempt by Elizabeth I to expel them in 1601. By the last third of the 18th century, there were an estimated 10,000 black people in Britain, mostly concentrated in cities such as London.

Has this presence left a genetic trace among people regarded as ‘indigenous’ British? In principle, Y-chromosomal haplotyping offers a means to detect long-established African lineages. Haplotypes of the non-recombining region of the Y, defined by slowly mutating binary markers such as SNPs, can be arranged into a unique phylogeny.  These binary haplotypes, known as haplogroups (hg), show a high degree of geographical differentiation, reflecting the powerful influence of genetic drift on this chromosome. Some clades of the phylogeny are so specific to particular continents or regions that they have been used to assign population-of-origin to individual DNA samples, and in quantifying the origins of the components of admixed populations using simple allele-counting methods.

Studies of British genetic diversity, generally sampling on the criterion of two generations of residence, have found no evidence of African Y-chromosomal lineages, suggesting that they either never became assimilated into the general population or have been lost by drift. However, here, we describe a globally rare and archetypically African sublineage in Britain and show that it has been resident there for at least 250 years, representing the first genetic trace of an appreciable African presence that has existed for several centuries…

Read the entire article here.

Colby Cosh: Obama’s family tree might have hung him from a limb

National Post
2008-10-24

Colby Cosh

Ever since Barack Obama won the Democratic nomination for the presidency, American political observers have been arguing endlessly over whether his race will be a net help or a hindrance to him at the polls November 4. Strangely, though, there has been less discussion over the crude binary characterization of Senator Obama as “black.”

Even in the most progressive American circles, it seems, the “one-drop rule” of racial categorization, a heritage of slavery, still holds sway. For taxonomic purposes, a man with a white mother and a black father is a black man. Obama discovered very early in life that he could not defy the rules of this game. And if he wins the election, his own biography will demonstrate that it is easier to succeed in America as a multiracial individual who self-identifies as black than it is to live with a blurred racial identity. Being “black” has enabled him to represent a dream of racial conciliation for all Americans more easily than being a trans- or post-racial figure would.

The strange part about this narrative is that Obama’s black ancestors aren’t even African-American; he is the son of a dynamic, brilliant Kenyan economist and politician he hardly ever knew. His black identity comes from outside American history. And reporters have barely scratched the surface of his white maternal ancestry, the part of him, so to speak, that lies fully within America, complete with all the contradictions and horrors of its past.

And here’s another strange fact: It is easier to show Barack Obama’s descent from slave-owning American colonists than it is to establish any genealogical connection between himself and American slaves. In many ways, a WASP family-tree snob of the 19th century would probably be more impressed with Obama’s mother’s background than with John McCain’s people. (Both candidates can claim direct descent from King Edward I.) A 2007 investigation by the Baltimore Sun found that Obama’s direct maternal ancestors included slaveowners from the time of William and Mary right down to the eve of the U.S. Civil War, a war in which he had family on both sides.

And the closer you look, the weirder things get…

Read the entire article here.

Inside the Color Line: Reading Biracialism in Twentieth Century American Culture

State University of New York, Albany
2005
191 pages
Publication ID: AAT 3181801
ISBN: 9780542221538

Habiba Ibrahim, Assistant Professor of English
University of Washington

A Dissertation Submitted to the University at Albany, State University of New York in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (College of Arts & Sciences, Department of English)

This project is conceived as an exploration of myth and society with regard to racial ambiguity in twentieth century literature and film. It attempts to trace “mixed” racialism as it acts as an alibi for cultural phenomena including those surrounding the (truth and fiction of the) color line. Through an analysis of various moments in twentieth century American culture, this project seeks to demonstrate that racial mixedness has and continues to function as a sign under which the aporia of national self-definition finds expression

Table of Contents

• Introduction: The Mulatto/a and the Task of Representation
• Chapter One: Passing Confrontations with Black Masculinity in The Autobiography of an Ex-Colored Man and Flight
• Chapter Two: Canary in a Coal Mine: Negotiating/Narrating Difference through Racial Mixedness in Caucasia and “Recitatif”
• Chapter Three: A Cross Between Reason and Feeling: Questions of Emergence and Textuality in The Intuitionist, Shadows and Cane
• Chapter Four: “The Thing Became Real”: Selfhood, the Image and Misrecognition in Quicksand and Mixing Nia
• Bibliograpy

Purchase the dissertation here.

SOCI3600 – The Multiracial Family

Univeristy of North Texas
Summer 2010

George Alan Yancey, Associate Professor of Sociology
University of North Texas

Academic study of the dynamics found in multiracial families. Important concepts in race/ethnicity studies such as assimilation, racial identity and pluralism. Other topics include passing, one-drop rule, interracial dating/marriage, bi- or multiracial identity and transracial adoption.

For more information, click here.

CeCe Ridder is a doctoral candidate in the Department of Higher Education Administration at The University of Texas at Austin and is recruiting University of Texas at Austin students for a research study about Black-White Multiracial college students.  She is seeking registered students at UT Austin in the third or fourth year of study and have one parent from a Black or African American racial category and one from a White or European racial category.   She would be very interested in speaking to them more about involvement or non-involvement in student organizations and racial identity. This interview is a conversation style, confidential process.

The title of this study is: Multiracial College Students: Exploring Racial Identity Through Student Organizations. The significance of this study is to explore how multiracial students utilize student organizations, and what influence this involvement has on racial and other social identities (gender, age, sexual orientation, etc). The implications for college administrators will be a more in depth understanding of multiracial students, and improve policy, curricula, advising and counseling.

The student participation will include a brief survey, one 60-90 minute in person interview and a 60 minute follow-up interview at a convenient time and location.  If you have any students in mind, can you please e-mail her his/her name and e-mail address and she can send them an e-mail, or feel free to send this request to them with her information, CeCe.Ridder@mccombs.utexas.edu or by phone (512) 789-7410.