Laron Syndrome: Siblings with Extreme Short Stature and Very High Growth Hormone

Abstract

Primary growth hormone resistance or growth hormone insensitivity syndrome (GHIS), also known as Laron syndrome, is a hereditary disease caused by deletions or different types of mutations in the growth hormone receptor gene or by post-receptor defects. This disorder is characterized by a clinical appearance attributable to severe growth hormone deficiency with high levels of circulating growth hormone in contrast to low serum insulin-like growth factor-1 (IGF-1) and low serum insulin-like growth factor binding protein (IGFBP-3)values. It is an autosomal recessive disorder and to date, more than 70 unique growth hormone receptor (GHR) mutations have been identified in more than 250 GHIS patients. We report the case of an 8-year-old boy and his 12-year-old sister born to first cousin parent that presented with severe short stature who had the classic feature of GH deficiency. Investigations revealed high plasma GH levels in both the cases. Subsequently, IGF-1 and IGFBP-3 assay were done and the levels were found to be very low. These reports along with elevated GH level in the context of typical picture of GH deficiency confirmed the diagnosis of GHIS. Genetic testing could not be done because of unavailability in our context. Regrettably specific therapy in the form of recombinant IGF-1 could not be offered as it is not commercially available in our country.