Genetics of Obesity, Diabetes, and Heart Disease in African Diaspora Populations

Background:

- African Americans have one of the highest rates of type 2 diabetes in the United States, and often have other medical problems related to obesity and cardiovascular disease. These conditions have various risk factors, including high blood sugar levels, high cholesterol levels, and insulin resistance. However, these risk factors have not been studied very closely in individuals with African ancestry, including Afro-Caribbean and sub-Saharan Africa migrant populations. Researchers are interested in conducting a genetic study on obesity, adult-onset diabetes, heart disease, and other common health conditions in individuals with African ancestry.

Objectives:

- To collect genetic and non-genetic information from individuals with African ancestry to study common health conditions related to obesity, adult-onset diabetes, and heart disease.

Eligibility:

- Individuals at least 18 years of age who self-identify as African American, Afro-Caribbean, or migrants from sub Saharan Africa.

Design:

• Participants will undergo a physical examination and will provide a blood sample for study.
• Participants will also answer questions about personal and family medical history and current lifestyle behaviors.
• No treatment will be provided as part of this protocol.

This research protocol is designed to study the genetic basis of the clustering of several metabolic disorders including Type 2 diabetes (T2D), hypertension, cardiovascular diseases (CVD), obesity, and other related conditions in populations of the African Diaspora. This project takes advantage of the well-established infrastructure and success of Dr. Anne Sumner's NIDDK clinical protocols. The project will aim to enroll subjects from her cohorts which include whites, African Americans and Africans living in the United States with the goal of performing quantitative trait analysis using a candidate gene approach to understand the genetic basis of serum lipid levels, blood pressure, fasting glucose, and other metabolic parameters. For aim 2, we propose to perform whole exome sequencing in a subset of cases (n=48, 96 chromosomes) to identify both rare and common variants for multiple metabolic parameters. Variants identified by the exome sequencing effort and by a current sequencing project of six candidate lipid genes will be genotyped in the entire cohort. Overall, these studies will further efforts to understand if black-white differences as well as differences within black populations exist in the genetic basis of T2D, CVD, and obesity. Given past activities, it is also anticipated that this resource will form the basis of multiple collaborations between Dr. Rotimi's lab, several NIH intramural researchers, and non-NIH scientists.

• Diabetes
• Cardiovascular Disease

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• Wolf SM, Lawrenz FP, Nelson CA, Kahn JP, Cho MK, Clayton EW, Fletcher JG, Georgieff MK, Hammerschmidt D, Hudson K, Illes J, Kapur V, Keane MA, Koenig BA, Leroy BS, McFarland EG, Paradise J, Parker LS, Terry SF, Van Ness B, Wilfond BS. Managing incidental findings in human subjects research: analysis and recommendations. J Law Med Ethics. 2008 Summer;36(2):219-48, 211. Review.

• INCLUSION CRITERIA:

Subjects will include unrelated persons who self-identify as white or African American, Afro-Caribbean or migrant from sub-Saharan Africa. Adults of African ancestry are prioritized for this study because of the paucity of genetics studies investigating the association of risk alleles contributing to the prevalence of T2D, CVD, obesity and other common conditions in this population.

EXCLUSION CRITERIA:

Children are excluded as these phenotypes present more commonly in adults. Attempts will be made to enroll an equal number of men and women. No prisoners, pregnant women or fetuses will be included in this study.