Regarding central hypothyroidism, the prevalence in subjects with PWS cannot be clearly established and has been reported as 2.1% to 72.2% [12]; on the other hand, more than half of the individuals with PCSK1 deficiency exhibit central hypothyroidism, similar to those presenting hypocortisolism [15]. Here, PCSK1 is linked to hyperinsulinemic hypoglycemia, familial, 4.