What causes FSHD?
Although the exact genetic defect in FSHD is known, it remains unclear how this defect results in muscle wasting and weakness.
In most genetic diseases, a mutation occurs in the sequence (code) of a particular gene which is then either unable to make an essential protein it codes for or makes a defective protein. In FSHD on the other hand, the genetic defect does not alter the sequence (code) of a particular gene. Instead, the defect is a loss of several copies of identical pieces of DNA (known as D4Z4 repeats) that cluster in large numbers on the tip of chromosome 4. If the number of D4Z4 repeats falls below 11, it results in FSHD. It is known that clusters similar to D4Z4 repeats may regulate when certain genes are turned on or turned off. Current research in FSHD is focused on three main possibilities:
- That the shortened number of repeats somehow turns on genes close to the D4Z4 repeats on chromosome 4 that are normally turned off.
- That the shortened number of repeats allows a dormant gene embedded within the D4Z4 repeat to turn on.
- That the shortened number of repeats can influence how one or more genes on other chromosomes are turned on or off.
- What is FSHD?
- How is FSHD inherited?
- What are the Symptoms of FSHD?
- Does FSHD affect other parts of the body?
- Is infantile FSHD different from other forms of FSHD?
- What can someone with FSHD Expect as they age?
- How is FSHD Diagnosed?
- What causes FSHD?
- Are there any treatments for FSHD?
For more information, please contact the Fields Center FieldsCenter@urmc.rochester.edu
