Dental and craniofacial characteristics in a patient with leprechaunism treated with insulin-like growth factor-I.

Leprechaunism is an autosomal recessive disease characterized by elfin-like faces, loss of glucose homeostasis, and severe insulin resistance. This disease is caused by inherited defects of the insulin receptor and is lethal early in life. Perhaps for this reason, the teeth and craniofacial features of patients with leprechaunism have never been reported. In the present case, the patient had been diagnosed with leprechaunism with mutation in the insulin receptor gene and had treatment with recombinant human insulin-like growth factor I (IGF-I) starting at the age of 1 year 7 months. It is of interest that all of his teeth were extremely large and subsequently showed severe crowding in the dental arches. He also showed a large tongue with an anterior open bite. He had a convex facial profile with a remarkably steep mandibular plane angle and large gonial angle. This is the first report of the characteristic phenotypes of the teeth and craniofacial morphology of a patient with leprechaunism treated with IGF-I. In addition, the possible association between these features and long-term IGF-I treatment is discussed.