There are many protocols to support diagnosis of genetic diabetes (Maturity Onset Diabetes of the Young/ Monogenic Diabetes). The Diabetes Genes (Exeter website) is an excellent source of information. https://www.diabetesgenes.org/what-is-mody/ 

Below is an example of a flow chart (reference: Ewan Pearson/ NHS Scotland) that also gives some guidance on MODY risk stratification. For more information on how this tool calculates risk see here.