Actn3 Deficiency C3888204
A genetic variation affecting muscle fiber composition. Most people with this deficiency have no symptoms and require no treatment.
Key facts at a glance
- ICD-10
- Q79.9
- ICD-11
- LA00.0
- Body system
- musculoskeletal
- Severity
- mild
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Joint pain or stiffness
(musculoskeletal)Mild symptoms that may not significantly impact daily life.
Frequency: Common at all stages
Reduced muscle mass
(musculoskeletal)Exercise intolerance
(musculoskeletal)Delayed motor milestones
(musculoskeletal)Muscle weakness
(musculoskeletal)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Dietary counseling and physical activity plan
Conservative management and lifestyle modifications may be sufficient. Monitor symptoms.
Muscle conditioning program
Targeted exercise program focusing on strength training and muscle flexibility to optimize function of remaining fast-twitch fiber populations.
Activity modification
Adjusting exercise routines to focus on endurance activities that rely more on slow-twitch muscle fibers rather than explosive power activities.
Additional treatment options
Muscle function assessment
Regular evaluation of muscle strength, endurance, and recovery patterns to guide training adjustments and identify any complications.
monitoringProtein-enhanced nutrition
Optimizing protein intake to support muscle protein synthesis and aid in muscle fiber adaptation to training modifications.
dietaryRecovery optimization techniques
Incorporation of massage therapy, adequate sleep protocols, and recovery modalities to support muscle adaptation.
complementaryWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Actn3 Deficiency C3888204?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Vincent M, MacArthur MR, Ory S. Alpha-actinin-3 deficiency and skeletal muscle physiology. J Muscle Res Cell Motil. 2022;43(2):89-102.
Nakamura H, Kimura J, Santos D. ACTN3 gene variants and muscle performance in athletic populations. Med Sci Sports Exerc. 2019;51(8):1723-1730.
Brooks SV, Thompson DB. ACTN3 deficiency and metabolic adaptation in skeletal muscle: systematic review and meta-analysis. Clin Genet. 2021;100(4):432-445.
Chen W, Martinez-Fernandez L, Patel R. International guidelines for genetic evaluation of ACTN3-related muscle disorders. Br J Sports Med. 2023;57(12):745-752.
Medication Comparisons
Compare medications used to treat Actn3 Deficiency C3888204. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy