This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
Laron dwarfism is due to 
Select and explain. 
A. GH deficiency, B. GHRH deficiency, C. GH receptor resistance, D. IGF-1 deficiency
C: GH receptor resistance
Answer: C: GH receptor resistance 
Explanation: Laron syndrome, or Laron-type dwarfism, is an autosomal recessive disorder characterized by an insensitivity to growth hormone (GH), usually caused by a mutant growth hormone receptor . It is caused by changes ( mutations ) in the GHR gene . This gene encodes growth hormone receptor, which is a protein found on the outer membrane of cells throughout the body. ... Mutations in GHR impair the function of growth hormone receptors which interferes with their ability to bind growth hormone . Ref - Harrison's internal medicine 20e p2657, 3417