INS and obesity due to melanocortin 4 receptor deficiency: Among these five clusters was one type 1 diabetes-like cluster (severe autoimmune diabetes, SAID) and four type 2 diabetes clusters, including an insulin-deficient cluster (severe insulin-deficient diabetes, SIDD), an insulin-resistant cluster (severe insulin-resistant diabetes, SIRD), an obesity-related cluster (mild obesity-related diabetes, MOD) and a remaining group with no extreme characteristics (mild age-related diabetes, MARD).