A deficiency in human growth hormone (q.v.) often due to deletions or point mutations at the GH1 locus. Deletions result in severe dwarfism by 6 months of age. hGH replacement is initially beneficial, but anti-hGH antibodies subsequently develop and may arrest the response to exogenous hGH. The lack of immunological tolerance to hGH occurs because the mutant fetus never produced hGH during the period when its immune system was being programmed not to respond to self-proteins. In cases where a biologically inactive, mutant hGH is produced, treatment with synthetic hGH is usually effective. See human growth hormone gene, human growth hormone receptor.
Subjects: Genetics and Genomics.