The growth delay due to insulin-like growth factor I (IGF-1) deficiency is characterized by a combination of prenatal and postnatal growth retardation, sonic alertness, and decreased intelligence. The syndrome is exceptionally rare, so far only 4 cases have been reported.
IGF-1 is a polypeptide hormone secreted mainly in the liver after stimulation with the growth hormone somatotropin and structurally very similar to insulin. It is indispensable for fetal and postnatal growth, brain development and metabolism. IGF-1 deficiency is inherited as an autosomal recessive trait. Originally, there are homozygous mutations in the gene for insulin-like growth factor 1 (IGF1; 12q22-q24.1).
Affected children are extremely small (size < 3 standard deviations) with a final size prediction of approximately 130 cm, a doll-like appearance with prominent forehead, small hips and taille, underdevelopment of the muscular system and obesity.
Other clinical symptoms include insulin resistance, partial gonadal dysfunction and osteoporosis. If there is a partial IGF-I deficiency, growth and microcephaly slow down preoperatively and postnatally. The development is in this case only slightly delayed and the quality of the property is not restricted. Therapeutically, with the administration of recombinant IGF-1 an acceleration of the growth, or an improvement of the final size of about 10 to 15 cm can be achieved. Due to the insulin-like effect of IGF-1, there is an increased risk of hypoglycemia.