Growth hormone receptor deficiency (Laron syndrome) in black African siblings

S Afr Med J. 1996 Mar;86(3):268-70.

Abstract

Non-Caucasians with growth hormone receptor (GHR) deficiency/Laron syndrome among the approximately 180 recognised cases are rare, and include a Japanese and 3 African Americans. Black African siblings, a brother and a sister seen initially at 11 years 9 months and 5 years 6 months of age respectively were -7,4 and -8,0 on the standard deviation score for height. They had characteristic features and biochemical findings including prominent forehead; depressed nasal bridge; central adiposity; high-pitched voices; micropenis; high GH levels and low levels of insulin-like growth factor (IGF)-I, IGF-II, insulin-like growth factor-binding protein 3 (IGFBP-3), and GH-binding protein (the solubilised extracellular domain of the GH cell surface receptor). Molecular genetic studies revealed a dinucleotide deletion in both siblings on exon 7 of the GHR gene, a mutation not found in any other GHR-deficient patient studied, including the North Americans of African origin. Since African Americans have a substantial admixture of Caucasian genes, it is of interest to document the presence of this condition in siblings from Africa.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Black People* / genetics
  • Child
  • Dwarfism / blood
  • Dwarfism / ethnology*
  • Dwarfism / genetics
  • Female
  • Gene Deletion
  • Humans
  • Insulin-Like Growth Factor Binding Proteins / blood
  • Insulin-Like Growth Factor Binding Proteins / deficiency
  • Insulin-Like Growth Factor I / deficiency
  • Insulin-Like Growth Factor II / deficiency
  • Male
  • Radioimmunoassay
  • Receptors, Somatotropin / deficiency*
  • Receptors, Somatotropin / genetics
  • South Africa
  • Syndrome

Substances

  • Insulin-Like Growth Factor Binding Proteins
  • Receptors, Somatotropin
  • Insulin-Like Growth Factor I
  • Insulin-Like Growth Factor II