Alternative titles and symbols : Growth hormone receptor deficiency; Growth hormone insensitivity syndrome; Pituitary dwarfism II;
Description : Laron syndrome is an autosomal recessive disorder characterized by marked short stature
that results from failure to generate insulin-like growth factor I (IGF1; 147440)
in response to growth hormone (GH; 139250). GH levels are normal or increased. The
disorder is caused by dysfunction of the growth hormone receptor. A Laron syndrome-like
phenotype associated with immunodeficiency (245590) is caused by postreceptor defect,
i.e. mutation in the STAT5B gene (604260). Patients with mutations in the GHR gene
that cause only partial insensitivity to growth hormone have a form of short stature
(604271).;
Inheritance : Autosomal recessive;
Molecular basis : Caused by mutation in the growth hormone receptor gene (GHR, 600946.0001);
Laboratory abnormalities : Normal or increased levels of GH; Low IGF1 despite normal or increased levels of GH; Failure to generate somatomedin (or insulinlike growth factor, IGF1) in response to
growth hormone;