Enolase deficiency, also known as Glycogen Storage Disease Type XIII (GSD XIII) or beta-enolase deficiency, primarily manifests with symptoms such as exercise intolerance, muscle pain (myalgia), and elevated creatine kinase (CK) levels, especially after intense physical activity. It can also lead to secondary issues like muscle contracture and rhabdomyolysis.
Key Symptoms of Enolase Deficiency
Individuals with enolase deficiency often experience a range of symptoms, particularly impacting muscle function during physical exertion.
Primary Symptoms:
- Exercise Intolerance: A diminished capacity to perform physical activity without experiencing undue fatigue or other discomfort. This is often one of the earliest and most noticeable signs.
- Myalgia: Muscle pain, which can range from mild discomfort to severe aching, particularly following physical exertion.
- Raised Creatine Kinase (CK) Levels: Blood tests may reveal elevated levels of creatine kinase, an enzyme released into the bloodstream when muscles are damaged. This elevation is typically observed after intense physical activity.
Secondary Manifestations:
If primary symptoms are not managed or with continued strenuous activity, more severe secondary conditions can arise:
- Muscle Contracture: A persistent shortening of muscle tissue, leading to stiffness and reduced range of motion.
- Rhabdomyolysis: A serious medical condition where damaged muscle fibers release their contents into the bloodstream. These substances can be harmful to the kidneys and may lead to kidney failure.
Related Conditions and Nomenclature
Enolase deficiency is specifically referred to by a few names, highlighting its classification within glycogen storage disorders:
| Other Name | Associated Condition |
|---|---|
| β(beta)-enolase deficiency | Glycogen Storage Disease Type XIII (GSD XIII) |
Management Considerations
While the focus is on symptoms, managing enolase deficiency often involves lifestyle adjustments to mitigate symptom severity. Recommendations typically include maintaining aerobic fitness while carefully avoiding activities that involve intense anaerobic exertion, which can exacerbate symptoms and lead to muscle damage.
