Diabetes is considered as a disease with a wide and continuous clinical spectrum, ranging from Type 1 (T1D) and Type 2 Diabetes (T2D) with complex multifactorial causes. In the last years, particular attention has been focused on the predictive value and therapeutic potential of single nucleotide polymorphisms (SNPs). SNPs can alter the seed-sequence in miRNA’s loci and miRNA target sites causing changes in the structure and influencing the binding function. Only few studies have investigated the clinical influence of SNPs, in particular potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ) gene variants in T1D population. The aim of the study is to investigate the occurrence and the possible metabolic significance of KCNJ polymorphism in a group of pediatric patients with T1D. The study was performed in a cohort of 90 Caucasian children and adolescents with T1D and 93 healthy subjects. Rs5210 polymorphism has been analyzed with a prevalence of the GG genotype in the patient group suggesting its association with T1D. Therefore, a relationship was found between GG genotype and body mass index (BMI) at diagnosis and insulin requirement (IR) after 6 months. The study suggested an action for rs5210 in determining the metabolic features of T1D pediatric patients, by showing some clues of insulin resistance in patients carrying that polymorphism.© Georg Thieme Verlag KG Stuttgart · New York.