MAP2K5 rs3815349: Sleep Movement and RLS Genetics
The genetic variant rs3815349 is an intronic single nucleotide polymorphism situated in the regulatory boundary between the MAP2K5 and SKOR1 genes on chromosome 15. Research in sleep medicine has investigated this locus for its statistical association with periodic leg movements of sleep and restless legs syndrome. Because complex traits arise from a combination of many genes and lifestyle factors, carrying risk alleles at this locus confers only a modest shift in statistical probability rather than a direct diagnosis.
What each genotype means
Typical risk profile
You carry two copies of the common G allele at rs3815349 in the MAP2K5/SKOR1 intergenic region. Population studies associate this genotype with baseline population risk for periodic leg movements of sleep and restless legs syndrome. Because overall susceptibility is shaped by many genetic loci alongside lifestyle and environmental factors, this result indicates an average baseline rather than an absence of risk.
Carried by approximately 60% to 70% of individuals of European ancestry and is the predominant genotype across most global populations.
Slightly increased susceptibility
You carry one copy of the A risk allele and one copy of the common G allele at rs3815349. Genome-wide association research links this single risk allele to a modest increase in susceptibility to restless legs syndrome and periodic limb movements during sleep. However, scientific evidence for this specific variant is limited and modest in effect, meaning carrying this allele does not cause or diagnose any sleep disorder.
Carried by approximately 28% to 35% of people of European ancestry; it occurs at lower frequencies in East Asian and African ancestries.
Moderately increased susceptibility
You carry two copies of the A risk allele at rs3815349 in the MAP2K5/SKOR1 regulatory region. In epidemiological studies, carrying both risk alleles is statistically correlated with higher odds of restless legs syndrome and periodic leg movements during sleep compared to carrying none. Current scientific evidence indicates only a modest contribution to overall risk, and this finding is not a medical diagnosis.
Carried by roughly 2% to 5% of individuals of European ancestry and is rare in most East Asian populations.
Genomic Location and Variant Classification
The single nucleotide polymorphism rs3815349 is located on chromosome 15 within an intronic region that spans the proximity of MAP2K5 and SKOR1. In genetic databases such as dbSNP, it is cataloged as a non-coding single-base transition, alternating between the major allele and the alternate variant allele. Because this change occurs within an intron rather than an exon, it does not alter an amino acid sequence directly. Instead, investigators classify it as a non-coding regulatory variant that may influence downstream gene expression, transcript splicing, or chromosomal chromatin conformation in neural tissues.
Biological Roles of MAP2K5 and SKOR1
The genomic locus where rs3815349 resides encompasses two biologically significant genes: MAP2K5 (Mitogen-Activated Protein Kinase Kinase 5) and SKOR1 (SKI Family Transcriptional Corepressor 1). MAP2K5 acts as a dedicated upstream kinase within the MAPK signaling cascade, specifically phosphorylating and activating ERK5. This pathway is critical for neuronal survival, neurogenesis, and central nervous system development. SKOR1, conversely, acts as a transcriptional repressor expressed predominantly in the central nervous system, particularly in the spinal cord and dorsal horn sensory pathways. Disruptions or regulatory alterations in this genomic neighborhood have been hypothesized to modify sensory-motor reflex arcs, dopamine neurotransmission, or cellular iron regulation implicated in sleep-related movement disorders.
Research Associations with Restless Legs and Sleep Movements
Genome-wide association studies (GWAS) and candidate gene analyses have repeatedly identified the MAP2K5/SKOR1 chromosomal region as a contributor to restless legs syndrome (RLS) and periodic leg movements of sleep (PLMS). Cohorts such as the Wisconsin Sleep Cohort and the Osteoporotic Fractures in Men (MrOS) study have evaluated polymorphic markers in this region alongside variants in MEIS1 and BTBD9. While earlier landmark discovery scans highlighted nearby proxy markers such as rs1026732, rs3815349 sits within the same linkage disequilibrium block. Current scientific evidence for rs3815349 specifically is classified as limited to moderate; while the broader locus clearly demonstrates reproducible associations, individual single nucleotide polymorphisms within the block contribute only fractional increases in relative odds.
Interpreting Results and Clinical Perspective
Discovering an individual genotype at rs3815349 provides informational insight into personal polygenic background, but it is not a clinical test. Restless legs syndrome and periodic limb movements are multifactorial conditions diagnosed through clinical history and objective polysomnography, not DNA sequencing alone. Carrying one or two susceptibility alleles does not guarantee that a person will ever develop nocturnal sensations or motor restlessness, nor does having the typical genotype guarantee protection. Environmental factors, dietary iron status, renal function, pregnancy, and sleep hygiene play substantial roles. Any individual experiencing persistent limb discomfort or fragmented sleep should seek evaluation from a qualified physician or sleep specialist rather than attempting to interpret their symptoms solely through genetic markers.
How common is this variant?
The minor allele frequency for rs3815349 ranges from approximately 0.15 to 0.22 in European populations, making heterozygotes relatively common, whereas allele frequencies vary across other global ancestral groups in public databases such as gnomAD and dbSNP.
Frequently asked questions
Does having the rs3815349 variant mean I will get restless legs syndrome?
No. Genetic variants identified in association studies like rs3815349 merely alter statistical probabilities by a small margin. Many individuals who carry the variant never develop symptoms, as clinical conditions like RLS depend on a combination of multiple genes, iron levels, and neurological factors.
What is the difference between RLS and periodic leg movements of sleep?
Restless legs syndrome is characterized by an urge to move the limbs, usually accompanied by uncomfortable sensations while awake during rest or evening hours. Periodic limb movements of sleep (PLMS) are repetitive, involuntary jerking or twitching movements that occur during sleep and are detected via nocturnal polysomnography.
Why are two genes, MAP2K5 and SKOR1, mentioned for one variant?
The variant rs3815349 lies in a non-coding genomic region between or within the boundary zone of MAP2K5 and SKOR1. Because non-coding variants can influence the transcriptional regulation of adjacent genes, scientific literature routinely refers to both candidate genes when discussing this locus.
Can I take medication based on my rs3815349 genotype?
No, this genetic variant is not an approved biomarker for selecting or dosing medications. Management of sleep-related movement symptoms should always be guided by a licensed medical provider based on clinical examination, diagnostic criteria, and standard laboratory assessments such as serum ferritin.
Sources & further reading
Educational information only, last refreshed 9/13/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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