Thousands of muscle variants
An allele‑specific analysis flagged 6,653 common genetic variants associated with thigh muscle volume, noting the signals are enriched in expression quantitative trait loci—facts that link DNA variation to muscle size at a fine scale. (x.com)
Researchers reported 6,653 allele-specific DNA variants in human skeletal muscle, a map that overlaps genetic signals tied to muscle volume. (biorxiv.org) The work appeared April 8, 2026, as a bioRxiv preprint from researchers in Russia, Australia, the United Kingdom and Japan. The team profiled 75 human skeletal muscles with cap analysis of gene expression sequencing, a method that reads where genes switch on, and paired part of that dataset with 22 matched proteomes measured by mass spectrometry. (biorxiv.org) People carry two copies of most genes, one from each parent, and allele-specific analysis asks whether one copy is more active than the other. When one copy consistently produces more RNA reads, that imbalance can point to a nearby regulatory variant that changes gene output. (pubmed.ncbi.nlm.nih.gov) That matters for muscle because most genome-wide association study hits do not directly name the gene they affect. Expression quantitative trait loci, often shortened to eQTLs, are DNA sites linked to changes in gene expression and are widely used to connect trait-associated variants to specific genes and tissues. (nature.com) The new preprint did not measure thigh size in living volunteers itself. Instead, it found that many of the 6,653 allele-specific variants coincided with muscle-related genome-wide association study signals, including signals for muscle volume. (biorxiv.org) Large imaging datasets have already shown that thigh muscle volume can be measured at scale. A 2024 Frontiers in Physiology paper analyzed magnetic resonance imaging scans from 44,520 United Kingdom Biobank participants and reported that muscle volume measures were linked to age, grip strength, physical activity, sarcopenia and frailty. (frontiersin.org) In that study, lower muscle volume tracked with worse health measures, while markers of muscle quality were especially informative for frailty. The result helped establish thigh and whole-body muscle imaging as a useful phenotype for population genetics studies. (frontiersin.org) The new atlas also widened the basic map of human muscle biology beyond thigh tissue. The authors reported 37,001 transcribed regulatory elements and 1,804 protein groups across the sampled muscles, with eye, tongue and diaphragm muscles showing especially distinct molecular profiles. (biorxiv.org) Because the paper is a preprint, its methods and claims have not yet passed peer review. But if the overlap with muscle-volume signals holds up, the dataset could give researchers a shorter list of variants to test when asking why some people build or lose muscle differently. (biorxiv.org)
