Poznan University of Medical Sciences, Institute of Pediatrics, Department of Pediatric Endocrinology and Rheumatology; Karol Jonscher’s Clinical Hospital, Poznan, Poland
Mutations in the INSR gene result in rare inherited syndromes causing insulin resistance, such as leprechaunism (Donohue syndrome), Rabson-Mendenhall syndrome and insulin resistance type A. Leprechaunism is an autosomal recessive disorder associated with extreme insulin resistance that leads to hyperinsulinemia, impaired glucose homeostasis, fasting hypoglycemia and postprandial hyperglycemia. Impaired insulin action causes prenatal and postnatal growth retardation. Lipoatrophy, dysmorphic facies, hypertrichosis, macrogenitosomia and hypertrophy of internal organs are also present. A male infant with congenital insulin resistance was born at term after a normal pregnancy with a weight of 1905 g (G; p. Thr107Arg homozygous missense mutation was found in exon 2.
