WDR35 rs7167736: Genetics and Facial Shape Variation
The genetic variant rs7167736 is a common single-nucleotide polymorphism located within the WDR35 gene region. Genome-wide association research has linked this variant to subtle, normal-range morphological variations in the lower human face, including the orientation of the chin (menton) and inward lower lip projection. It reflects common anatomical diversity rather than a medical condition or health disorder.
What each genotype means
Typical lower facial projection
You carry two copies of the G allele at this locus near WDR35. In genome-wide association research on normal human facial morphology, this genotype is generally associated with the baseline orientation of the lower lip and menton (chin area). Because facial shape is highly polygenic and the evidence for this specific variant is limited, this marker explains only a subtle fraction of natural variation in facial contours.
Carried by approximately 34% of individuals globally, being the most common genotype in European and African populations.
Intermediate lower facial variation
You carry one copy of the G allele and one copy of the T allele at this locus. Research on 3D craniofacial variation indicates an intermediate statistical tendency toward altered inward projection of the lower lip and chin orientation. Facial features are shaped by hundreds of genetic factors and environmental development, meaning this single variant has a very small individual effect.
Carried by approximately 49% of individuals globally, representing the most frequent genotype worldwide.
Altered lower facial contour
You carry two copies of the T allele at this locus near WDR35. Published 3D morphometric studies associate this genotype with a modest statistical shift in lower facial projection, particularly involving the lower lip and menton orientation. The overall scientific evidence remains limited, and this variant represents normal aesthetic diversity rather than a medical or developmental condition.
Carried by approximately 17% of individuals globally, occurring more frequently in certain East Asian lineages.
What Is rs7167736 and Where Is It Located?
The variant rs7167736 is a single-nucleotide polymorphism (SNP) situated on chromosome 2 within the genomic neighborhood of the WDR35 gene. At this specific genetic position, individuals typically inherit either a guanine (G) or a thymine (T) nucleotide. Because every person receives one set of chromosomes from each biological parent, possible genotype combinations include GG, GT, or TT. Rather than altering a crucial protein-coding sequence directly, rs7167736 is categorized as a non-coding or regulatory-region variant. Such common variants frequently reside within regulatory elements, such as transcriptional enhancers or promoters, subtly modulating how neighboring genes are expressed during early biological development. Scientific investigations into human appearance employ large-scale array genotyping and imputation methods to track SNPs like rs7167736, aiming to pinpoint how broad regional chromosome architectures influence complex human physical traits across different populations.
The Biological Role of the WDR35 Gene
The WDR35 gene encodes WD repeat domain 35, also known as intraflagellar transport protein 121 (IFT121). This protein is an indispensable component of the IFT-A complex, which facilitates retrograde molecular transport within primary cilia. Primary cilia are microscopic, hair-like cellular appendages that act as sensory antennae on human cells, playing central roles in signal transduction pathways like Hedgehog and Wnt signaling. These signaling cascades are vital during embryonic craniofacial development and skeletal patterning, directing how neural crest cells migrate and differentiate into facial bones, cartilage, and soft tissues. Severe, pathogenic loss-of-function mutations in WDR35 lead to rare ciliopathies—such as cranioectodermal dysplasia (Sensenbrenner syndrome) and short-rib thoracic dysplasia—which are characterized by pronounced skeletal and craniofacial anomalies like everted lower lips and craniosynostosis. However, common non-coding polymorphisms like rs7167736 do not cause ciliopathies; instead, they appear to gently tune normal morphological processes.
Current Scientific Evidence and Facial Associations
Genome-wide association studies (GWAS) utilizing three-dimensional (3D) surface imaging have investigated how genetic variation shapes normal facial diversity. In these high-resolution imaging scans, rs7167736 was highlighted in association with subtle alterations in lower facial geometry, specifically influencing the inward projection of the lower lip and menton (chin) orientation. Despite this intriguing biological plausibility—especially given the established role of WDR35 in craniofacial morphogenesis and ciliary transport—the overall statistical evidence supporting this single variant remains classified as limited. Complex physical traits like facial shape are profoundly polygenic, shaped by the cumulative interplay of hundreds of distinct genetic loci, each exerting a very small individual effect size. Furthermore, association signals can be sensitive to phenotyping algorithms, imaging landmarks, and cohort ancestries, meaning that rs7167736 alone explains only a minute fraction of overall facial appearance and requires continued replication in diverse cohorts.
How Common Is rs7167736 Across Populations?
The rs7167736 polymorphism is a highly common variant found throughout global populations. According to large aggregate sequencing databases like the Genome Aggregation Database (gnomAD), the global minor allele frequency is well balanced, with the G allele observed at a frequency of approximately 0.58 and the T allele at approximately 0.42. Because both alleles occur at substantial frequencies worldwide, homozygous and heterozygous genotypes are all widely distributed across various geographic ancestries. Consequently, possessing one or two copies of either allele is entirely typical and represents ordinary human genetic variation. The widespread distribution of these alleles demonstrates that subtle structural variation in the lower face is part of the natural baseline of human physical diversity, rather than an isolated or evolutionarily restricted anomaly.
What You Can and Cannot Do with This Information
Learning your rs7167736 genotype provides an educational glimpse into how statistical genomics identifies subtle variations in human morphology. However, it is essential to understand the limits of this information. Having a specific genotype at rs7167736 cannot predict your exact facial appearance, chin shape, or lip contour in a photograph or mirror. Countless factors—including thousands of other genetic variants, biological sex, age, developmental environment, dental occlusion, and overall body composition—play a far greater combined role in determining facial architecture. Most importantly, rs7167736 is not a pathogenic mutation; it does not confer a clinical diagnosis of a craniofacial condition or a ciliary disorder. This marker is purely descriptive of population-level trait trends and should never be used as a basis for personal medical, cosmetic, or dental health decisions.
How common is this variant?
The rs7167736 variant is common worldwide, with the global gnomAD catalog reporting allele frequencies of approximately 0.58 for the G allele and 0.42 for the T allele. Because both alleles are prevalent, GG, GT, and TT genotypes are all widely observed across diverse ancestral groups.
Frequently asked questions
Can rs7167736 determine the exact shape of my chin or lips?
No, rs7167736 cannot reliably predict your precise facial appearance. Human facial morphology is polygenic, resulting from hundreds of genetic variants interacting with developmental, environmental, and dental factors. The variant only reflects very small statistical trends observed across large study cohorts.
Is rs7167736 linked to any disease or medical condition?
No, rs7167736 is categorized strictly as a normal physical trait variant with no known disease associations. While rare, destructive mutations in the WDR35 gene can cause severe ciliopathies, common non-coding variants like rs7167736 do not cause developmental syndromes or clinical illness.
What does inward projection of the lower lip mean?
In 3D craniofacial anthropometry, inward projection refers to the subtle anterior-posterior positioning of the lower lip relative to neighboring structural landmarks such as the chin point (menton). Research studies use automated digital coordinate maps to detect microscopic shifts in these contours across thousands of scanned individuals.
Is either genotype considered better or worse?
Neither genotype is favorable or unfavorable. All genotypes at rs7167736 are considered neutral, representing typical, benign human anatomical variation that has coexisted across human populations for thousands of generations.
Sources & further reading
Educational information only, last refreshed 9/12/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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