Question

Explain, step by step, from transcription to translation to activation, how a mutation in the GH1 gene, which codes for Growth Hormone, can lead to dwarfism. Use the information provided in the context of the lecture today to support your answer.

Answer 1

A mutation in the GH1 gene can cause dwarfism by leading to defective transcription, translation, or activation of Growth Hormone (GH), resulting in inadequate production of insulin-like growth factors (IGFs) and thus insufficient bone and muscle growth.

Step-by-step explanation:

A mutation in the GH1 gene, which codes for Growth Hormone (GH), can lead to dwarfism through the following processes:

1. Transcription - Normally, the GH1 gene is transcribed into mRNA in the pituitary gland cells.
2. Translation - The mRNA is then translated into the GH protein.
3. Activation - GH stimulates the liver to produce insulin-like growth factors (IGFs), which promote the uptake of amino acids for protein synthesis, crucial for growth in bones and muscles.
4. If there is a mutation in the GH1 gene, the resulting GH may be nonfunctional or deficient, leading to a decrease in production of IGFs, which in turn, fails to stimulate normal bone and muscle growth, resulting in pituitary dwarfism.

This type of dwarfism is characterized by symmetric body formation and normal mental and sexual development. Treatments often involve injections of synthetic human growth hormone (HGH) to help promote normal growth in children with GH deficiency.