Genetic predisposition to T2D was studied widely during the last decades.2, 3, 4 At present, around 50 candidate genes are considered to increase the likelihood of T2D, of which adiponectin gene (ADIPOQ), potassium channel, inwardly rectifying subfamily J, member 11 (KCNJ11) and transcription factor 7‐like 2 (TCF7L2 [IVS3C>T]) may be associated with insulin resistance and β‐cells dysfunction.5, 6, 7, 8, 9, 10, 11, 12, 13 Carriage of various SNP combinations may explain clinical heterogeneity of this disease. This evidence concerns the gene KCNJ11 and type 2 diabetes mellitus.