MC4R and early-onset autosomal dominant Alzheimer disease: The top-20 scoring GDAs from DisGeNET (Table 2) are very well-studied gene-disease relationships, like Alzheimer Disease and APP [amyloid beta (A4) precursor protein], obesity and MC4R (melanocortin 4 receptor), and Type 2 Diabetes Mellitus and IRS1 (insulin receptor substrate 1).