Lifestyle and Preventive Health
ACTN3 Gene by Country 2026
- The ACTN3 577XX genotype is a variation that results in reduced strength, muscle mass, and fast-twitch fiber diameter, but increased resistance to fatigue and metabolic efficiency in skeletal muscle.
- Ln is an abbreviation for natural logarithim.
- Gene frequency data is collected from multiple studies, which vary in precision from whole percentages to hundredths of a percent.
- The Bantu peoples are an ethnolinguistic grouping of approximately 400 distinct native African ethnic groups who speak Bantu languages and display a 577XX frequency of 1%. Bantu are native to 24 countries spread over a vast area from Central Africa to Southeast Africa and into Southern Africa.
ACTN3 577XX A genetic variant associated with reduced production of alpha-actinin-3, a protein found in fast-twitch muscle fibers.
Fast-Twitch vs. Slow-Twitch Fibers Fast-twitch fibers support explosive power and speed, while slow-twitch fibers are more efficient for endurance activities.
Genetic Frequency (%) The share of a population carrying a specific genetic variant, which can vary across regions due to ancestry and environmental factors.
Countries With High ACTN3 577XX Frequency
Countries with higher frequencies of the ACTN3 577XX variant typically exceed roughly 18%, indicating a larger share of the population with reduced expression of fast-twitch muscle protein.
These countries include Sweden, Japan, Italy, Spain, Greece, and Israel.
Countries With Moderate ACTN3 577XX Frequency
Countries with moderate frequencies of the ACTN3 577XX variant generally fall between roughly 10% and 18%, reflecting a more balanced distribution across populations.
These countries are China, Papua New Guinea, Russia, Ethiopia, Lithuania, and Australia.
Countries With Low ACTN3 577XX Frequency
Countries with low frequencies of the ACTN3 577XX variant typically fall below 10%, indicating that the non-functioning form of the gene is relatively rare.
Kenya is the only country in this dataset that falls into this category.
How Geography Relates to ACTN3 Variation
Geographic and environmental factors may help explain differences in ACTN3 577XX frequency across populations, particularly when comparing latitude and climate.
Higher frequencies are generally observed in countries at higher latitudes with cooler average temperatures, such as Sweden, Russia, and Lithuania, while lower frequencies appear closer to the equator in warmer regions like Kenya and Papua New Guinea.
