About Titin Myopathy (Titinopathy)

What is Titin?
  • Titin is a very large protein. In fact, it is the largest protein known to exist in the human body.
  • The titin protein is located in each of the individual muscle cells within the muscles that move our bodies.
  • In muscle cells, titin is part of the sarcomere, which is responsible for muscles contracting and relaxing.
  • Titin is particularly responsible for the normal “elasticity” of muscle (after your muscle does the work of contracting, the titin protein helps the muscle to stretch back into the muscle’s resting position).
  • Because the titin protein is important for muscle function, a problem with the titin protein causes problems with muscle function. This causes  muscle weakness.
What is a Titin Myopathy?
  • In medical terms, “-opathy” at the end of a word means that the term describes a medical disease or condition.
  • “Myo” refers to muscle and thus a “myopathy” is a medical illness involving muscles. This typically results in muscle weakness and muscle fatigue.
  • “Titin Myopathy” is a specific category of myopathy where the myopathy (muscle problem) is caused by an abnormality of the Titin protein.

Terminology: “Titin Myopathy” versus “Titinopathy”

  • “Titin Myopathy” is  sometimes referred to as “Titinopathy” (where “Titinopathy” just means a medical condition involving a problem with the titin protein).
  • Either term can be used, but…
  • “Titin Myopathy” is a more descriptive term than “Titinopathy”, since “Titin Myopathy” explicitly lets the reader know that the affected patient is suffering from a muscle (“myo”) problem.
  • (For example, most doctors, nurses, and other health professionals would understand that “Titin Myopathy” is a muscle disorder causing weakness, even if they had never heard of it before. Conversely, a health professional first hearing the term “Titinopathy” would probably have no idea what body tissues were involved or what symptoms such a patient might have.

How severe are Titin Myopathies?

  • The severity of titin myopathies (titinopathies) is variable.
  • Some patients have milder symptoms while others are much more severely effected.
Where can I learn more?