Definition:

Laron syndrome is a rare autosomal recessive disease characterized by insensitivity to growth hormone (GH). The disorder is caused by mutations of the gene encoding the GH receptor (GHR), leading to defective functioning of the GH-IGF1 signalling pathway. The main phenotypic feature is dwarfism, noticeable from birth. Patients have an elevated level of GH and undetectable, or very low IGF1 concentrations in serum.