@godisveryreal According to twin studies cited in these articles, the heritability of Type 2 & Type 1 diabetes is very similar & around 70%:
Type 2 study
https://www.sciencedirect.com/science/article/pii/S1871402119304047
Type 1 study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5918237/