PCSK1 deficiency is a rare genetic condition in which the homozygous presentation has been documented to cause diarrhea during infancy, as well as childhood obesity, high levels of proinsulin, and diverse endocrine abnormalities.<h4>Case description</h4>An eleven-year-old male was evaluated in the pediatric cardiology clinic for hypertriglyceridemia and rapid weight gain. The gene discussed is INS; the disease is hypertriglyceridemia.