While there have been two reports about CHI associated with CACNA1D variants, coding for the CaV α1 subunit of the CaV1.3 calcium channel, which is also expressed in human pancreatic beta cell [20,21], to our knowledge, CACNA1C-associated cases of CHI have not yet been reported. The gene discussed is CACNA1C; the disease is congenital isolated hyperinsulinism.