Transepidermal water loss refers to the extent of water molecules permeating from the hydrated layers of the dermis or epidermis (skin) to more dehydrated skin layers. This permeability can be affected by our environmental exposures: temperature, seasonal variation, sun exposure, and smoking, to name a few. Interestingly, this property of the skin seems to be different between different ethnicities, which suggests that genetics can also play a part.
Why do we even care though? Apart from cosmetics, who cares about water loss in our skin? Actually, this property of skin actually matters a lot if we are thinking about skin diseases like atopic dermatitis or eczema, which causes our skin to become very red and itchy. Nobody wants that. Unfortunately, however, it has been shown that the higher your transepidermal water loss is, the more you are at risk of developing eczema.
Looking at this further, a 2017 study examined the genetic underpinnings of transepidermal water loss among Han Chinese participants in a genome-wide association analysis. Investigators found a specific chromosome band (9q34.3) that was associated with the extent of water loss. Among the various gene loci within this band, those who had the non-mutated (or ancestral) gene variant at one specific locus had a lower transepidermal water loss (in other words, less water permeability) compared to those with the mutated gene variant. These results are consistent with the ethnic differences we talked about: Africans are more likely to have the non-mutated gene variant compared to other ethnicities, and, true enough, Africans have been previously reported to have reduced epidermal permeability compared to Asians or Caucasians. Learn a little more about the investigation here: https://www.ncbi.nlm.nih.gov/pubmed/28011148
Although the study only included 611 samples, it provides some preliminary genetic evidence to suggest what is genetically driving some risk for skin conditions. Further research is warranted, but this investigation is certainly a good start.
So what about you? Are you genetically at risk for transepidermal water loss? Find out on Genomelink now.