Question

What gene variant causes fragile X syndrome? What does this gene do?

a) FMR2; regulates muscle growth
b) FMR1; regulates neural development
c) FMR3; controls metabolic processes
d) FMR4; maintains bone density

Answer 1

Fragile X syndrome is caused by a mutation in the FMR1 gene, which is responsible for regulating neural development.

Step-by-step explanation:

The gene variant that causes Fragile X syndrome is a mutation in the FMR1 gene. This gene is known to regulate neural development. It does so by producing a protein called FMRP that is involved in the transport of messenger RNA to the neural dendrites and in the modulation of the synthesis of other proteins. The mutation in Fragile X syndrome is typically an expansion of a CGG triplet repeat located in the gene sequence of the FMR1 gene itself, leading to the inability of the cell to produce the FMRP protein which then results in the symptoms associated with Fragile X syndrome. The involvement of this gene in neural development also illustrates how genetic environmental correlation can play a role, as the expression of genes like FMR1 can affect how neurons form and how the brain functions in response to the environment.