Less severe disease is usually caused by an autosomal dominant gene mutation in the INSR gene, in which patients present in the peri-pubertal stage or beyond with acanthosis nigricans, dysglycemia (either fasting hypoglycemia and postprandial hyperglycaemia or frank diabetes) in the presence of severe hyperinsulinemia, oligomenorrhea, and hyperandrogenism in women. The gene discussed is INSR; the disease is acanthosis nigricans.