Novel mutation involving the translation initiation codon of the growth hormone receptor gene (GHR) in a patient with Laron syndrome.

Laron syndrome (LS) or growth hormone (GH) insensitivity syndrome (GHIS) is an autosomal recessive disease due to molecular defects in the GH receptor gene (GHR). Most of the identified mutations are located on the extracelular domain of the receptor. We studied the GHR gene in a patient with LS and found a homozygous missense mutation in exon 2. The novel mutation is an A-->T transversion (ATG -->TTG) that abolishes the translation initiation codon of the GHR gene. This mutation is expected to prevent the translation of the protein. We present clinical, biochemical and molecular evidence of Laron syndrome as the result of a mutation (ATG-->TTG) in the codon for the initial methionine of the GHR gene.