Family Investigation of Nephropathy and Diabetes

The Family Investigation of Nephropathy and Diabetes (FIND) was a multicenter observational study designed to identify genetic determinants of diabetic kidney disease. Study subjects were recruited from eleven centers and in many ethnic groups throughout the United States for a genome-wide association study (GWAS). Two additional strategies were also used to localize susceptibility genes: a family-based linkage study and a case-control study using mapping by admixture linkage disequilibrium (MALD).
In the family-based study, participants with diabetic nephropathy were recruited with their parents and selected siblings. Linkage analyses were conducted to identify chromosomal regions containing genes that influence the development of diabetic nephropathy and related quantitative traits. Subsequently, a GWAS was carried out.

Two types of MALD studies were done. The first was a case-control study of unrelated individuals of Mexican American heritage in which both cases and controls had diabetes, but only the case had nephropathy. The second was a case-control study of African American patients with nephropathy (cases) and their spouses (controls) unaffected by diabetes and nephropathy; offspring were genotyped when available to provide haplotype data.
Through the family and MALD studies, the FIND study identified several genes that contribute to diabetic nephropathy, albuminuria, and glomerular filtration rate (GFR), including ApoL1.