Emerging treatment options for patients with Laron syndrome

Introduction: Laron syndrome (LS) (OMIM#262500) is a rare autosomal recessive hereditary disease caused by deletions or mutations in the human growth hormone (hGH) receptor. These defects lead to GH insensitivity and a lack of insulin-like growth factor-1 (IGF-I) generation. The hormone deficiencies cause dwarfism and abnormal metabolic changes. The only treatment is recombinant human (rh) IGF-I. Areas covered: Descriptions of the rhIGF-I preparations are available and a review of their quality and availability are covered. The acute short-term and long-term effects of rhIGF-I during the treatment of patients with LS are reviewed based upon the literature and the author's own experience. The report also summarizes both the beneficial and adverse effects of rhIGF-I administration, mentioning ways to reduce or avoid the latter. An important finding is that homozygous, but not heterozygous, patients for LS are protected from developing cancer even if treated with IGF-I for years. Expert opinion: Daily injection of rhIGF-I is the only drug available for LS; it stimulates linear growth and protein anabolism but causes progressive obesity, for which no remedy has been found so far. Early diagnosis and prenatal counseling are advised. Future hopes are the synthesis of a long-acting rhIGF-I preparation and availability of treatment for all LS patients worldwide.