Race and Kidney Disease Outcomes: Genes or Environment?

Characterization of autosomal copy-number variation in African Americans: the HyperGEN Study

African Americans are a genetically diverse population with a high burden of many, common heritable diseases. However, our understanding of genetic variation in African Americans is substandard because of a lack of published population-based genetic studies. We report the distribution of copy-number variation (CNV) in African Americans collected as part of the Hypertension Genetic Epidemiology Network (HyperGEN) using the Affymetrix 6.0 array and the CNV calling algorithms Birdsuite and PennCNV. We present population estimates of CNV from 446 unrelated African-American subjects randomly selected from the 451 families collected within HyperGEN. Although the majority of CNVs discovered were individually rare, we found the frequency of CNVs to be collectively high. We identified a total of 11 070 CNVs greater than 10 kb passing quality control criteria that were called by both algorithms - leading to an average of 24.8 CNVs per person covering 2214 kb (median). We identified 1541 unique copy-number variable regions, 309 of which did not overlap with the Database of Genomic Variants. These results provide further insight into the distribution of CNV in African Americans.

Chronic kidney disease prevention in Singapore

In consideration of the epidemiologic basis for screening and surveillance, a comprehensive program for chronic kidney disease prevention was initiated in Singapore by the National Kidney Foundation Singapore (NKF Singapore) in 1997. Reasons for developing this include the rising rate of end-stage renal disease in the country, and the projected escalation because of the increase in chronic diseases that lead to end-stage renal disease (ESRD) such as diabetes mellitus and hypertension. Presented are progress and preliminary findings of this program, as well as that of the parallel initiative of Singapore's Ministry of Health. The NKF Singapore program incorporates primary, secondary and tertiary approaches to the prevention of chronic kidney disease. These include the population-based screening for early chronic kidney disease and chronic diseases that are associated with kidney disease and the implementation of disease management programs that aim to improve the multi-faceted care of patients with chronic diseases that lead to ESRD, including the development of community-based "Prevention Centers." The screening program identified risk factors for proteinuria, including the Malay race, increasing age, family history of kidney disease, and higher levels of systolic and diastolic BP even within the normal ranges. Longitudinal follow-up of both prevention programs are critical to provide evidence for the efficacy of such screening and intervention programs in improving chronic kidney disease outcomes, while reducing the cost of care.