The Presence of Normal Levels of Serum Immunoreactive Insulin-like Growth Factor 2 (IGF-2) in Patients with Down's Syndrome

Abstract
The present study was performed to further investigate the levels of somatomedins in Down's syndrome (DS). The results show that the serum levels of immunoreactive insulin-like growth factor 2 (RIA-IGF-2) in patients with DS is within the normal adult range. No age variation among the patients was observed. Since we earlier reported a deficiency of immunoreactive insulin-like growth factor 1 (IGF-1) in DS patients, present study showing normal RIA-IGF-2 levels suggests a selective deficiency of IGF-1 in DS.