The participant underwent an oral glucose tolerance test (OGTT) at the beginning of the study, and her fasting plasma glucose rose from a starting value of 149 mg/dL to 347 mg/dL at 2 h—this large increase is also suggestive of diabetes caused by a pathogenic HNF1A variant, as is the participant's consistently low C-reactive protein levels (Gardner and Tai 2012). This evidence concerns the gene HNF1A and diabetes mellitus.