How is "Facial Telangiectasia" encoded by the genome?
Facial telangiectasia can cause discomfort, and some people may feel self-conscious about marks appearing on their faces. Telangiectasia is most likely to develop in areas of the face or body that are consistently exposed to the sun and other elements. Fortunately, facial telangiectasia does not usually indicate a serious health problem. Those who are bothered by the visual or physical effects of the condition can undergo a medical procedure to have the telangiectases removed.
What Is Facial Telangiectasia?
Humans age gradually. Sadly, biological aging is inevitable for all of us, but some people experience different body changes as a result of aging, than others. One example is telangiectasia, also known as “spider veins”. Spider veins are small dilated blood vessels visible in the skin, which varies in color from red to blue. They can appear any where on the body, but when they appear on the face, and are often linear or branched-like vessels. Along with wrinkles, pigmented spots, xerosis, and skin sagging, spider veins are recognized as a skin-aging phenomenon. Skin aging research shows that UV exposure is an important risk factor for all signs of skin aging, but other determinants, such as skin color, have different effects on the different features of skin aging experienced by individuals.
What Causes Facial Telangiectasia?
Research has not found a single cause of telangiectasia. Researchers believe a combination of environmental and genetic factors is to blame. Chronic sun exposure in a climate with extreme temperatures is one of the main environmental factors. Other potential causes of spider veins include:
- Pregnancy (added pressure on venules)
- Alcoholism
- Rosacea
- Habitual use of corticosteroids
- Aging
- Dermatomyositis
- Scleroderma
- Systemic lupus erythematosus
Spider veins are a common, benign skin disorder. Healthy people can develop telangiectasia. However, in some cases, telangiectasia can be a warning sign of a serious illness, such as the rare genetic condition hereditary hemorrhagic telangiectasia (HHT).
What Is Facial Telangiectasia Associated With?
Facial telangiectasia is closely associated with connective tissue diseases, such as scleroderma, dermatomyositis, and lupus. In the case of scleroderma, it is thought that telangiectasia is a marker of ongoing vascular injury. Spider veins are most typically found in sun-exposed areas among individuals with dermatomyositis. Areas like the neck and chest, shoulders, upper back, and arms as well as the face are most vulnerable. People with lupus may also experience spider veins in the nail folds and on the edges of discoid lupus lesions. In this case, telangiectasia is associated with Raynaud’s phenomenon and the systemic disease of lupus.
Genetic Factors and Facial Telangiectasia: Insights From a Genome-Wide Association Study
Telangiectasia is a lesser studied phenotype, and its origins and risk factors remain to be fully understood. A recent GWAS study in Han Chinese women revealed that single nucleotide polymorphism (SNP) rs191497052 located in the KIDINS220 gene is associated with increased facial telangiectasia. In another recent study, the heritability of telangiectasia was estimated to be low. However, this does not factor how specific genetic variants could be associated with the degree of telangiectasia individuals may experience.
Researchers performed a genome-wide association study (GWAS) on facial telangiectasia in the Rotterdam Study (RS, n=2,842) to identify the specific gene variants associated with telangiectasia. Two independent cohorts were further tested to replicate the association. Additionally, a candidate gene approach with known pigmentation genes was performed. Facial telangiectasia was digitally identified using standardized high-resolution facial photographs. This provided a percentage of the total facial area which was covered with telangiectasia. The results of three GWASs results (RSI, RSII and RSIII) were meta-analyzed by researchers to reveal that some of the SNPs showed an association with facial telangiectasia with suggestive significance. Although none surpassed the significance threshold, the most strongly associated SNPs included rs12230938 in the SLC16A7 gene, rs9710520 in the ZSCAN4 gene, rs77766535 in the KCNN3 gene, and rs118021692 in the STAU2-AS1 gene. Some of these genes are linked to the vascular system. None of the top SNP associations were replicated in the two independent cohorts despite these suggestive results. In the candidate gene approach, increased telangiectasia was significantly associated with known pigmentation SNPs such as rs16891982 in the SLC45A2 gene.
In this study on a northwestern European population, no genome-wide significant SNPs were found. However, suggestive signals show that genes involved in in the vascular system might be involved in telangiectasia. It also showed association between pigmentation genes and the link between skin color and telangiectasia. Much larger studies are now required to replicate suggestive signals and to identify the influences of DNA sequence variants on telangiectasia. Read more about the study here: https://pubmed.ncbi.nlm.nih.gov/33095951/
Are you interested in learning more about your genetic tendency for facial telangiectasia? You can login to your Genomelink YOUR TRAITS to see this new genetic trait.
