In our study we found that the FGF23 median serum levels were significantly higher in T2D patients with ICAS than in diabetic control [67.7 (59.5–77.8) pg/mL and 43.89 (37.5–50.4) pg/mL (p < 0.001) respectively]. Here, FGF23 is linked to familial isolated congenital asplenia.