Proprotein convertase-1/3 deficiency is an autosomal recessive disorder characterized by neonatal severe generalized malabsorptive diarrhea and failure to thrive. As the disease progresses, additional endocrine abnormalities develop, including diabetes insipidus, growth hormone deficiency, primary hypogonadism, adrenal insufficiency, and hypothyroidism (summary by Wilschanski et al., 2014).