Figure 5.

A genetic risk score of 18 SNPs predicts type 2 diabetes. A: Shows the distribution of an 18-SNP genetic risk score, where FHS individuals were scored with a 0 if they had no risk alleles at a given SNP, one if they were heterozygous, and two if they were homozygous for the risk allele. Individuals who developed type 2 diabetes over 28 years of follow-up have about 0.6 more risk alleles than those who remain free of diabetes (P < 0.0001). B: Shows that risk for type 2 diabetes increases with increasing genetic risk burden. Those with 16–20 risk alleles have a risk of diabetes of 1.6, and those with ≥21 risk alleles have a risk of 2.5 relative to those with ≤15 risk alleles (P < 0.001). However, the genetic risk score does not discriminate those who will develop type 2 diabetes from those who will not after accounting for common clinical risk factors (age, sex, family history of diabetes, and metabolic syndrome traits). C: Shows that the area under the receiver operating characteristic curve (the C statistic) was 0.900 for a simple clinical model including clinical risk factors (gray line), and 0.901 for a model including clinical risk factors and the genetic risk score (black line) (adapted from Meigs et al. [[29]).