Ever wonder why Elizabeth Taylor had such compelling eyes? It turns out that she probably carried a mutation for doubled eyelashes, also known as distichiasis.[article]
This article explains the genetic mutation that causes double lashes. Learn how to check your genetic data to see if you carry the mutation.
Distichiasis: Double Eyelashes
Being born with double eyelashes is caused by a mutation in the FOXC2 gene.
The FOX (forkhead box) family of genes codes for a type of protein known as a transcription factor. This type of protein turns on and off genes during development as well as during cellular replication. Some of the FOX genes are important for longevity.
Related article: Longevity genes and FOXO3A
The FOXC2 gene turns genes on and off during prenatal development.
So what do lymphatic valves and heart development have to do with double eyelashes?
The mutation in the FOXC2 gene causes a double row of lashes to form during the baby’s development. It turns on transcription for eyelash development too much. This mutation can also cause droopy eyelids and yellowish nails.
Additionally, the FOXC2 mutation causes a predisposition to lymphedema (swelling of the arms and legs) and an increased risk of congestive heart failure.[ref]
Sadly, the poster-child of double lashes, Elizabeth Taylor, also died of congestive heart failure.
How rare is a double set of eyelashes?
The FOXC2 mutations are rare enough that the mutations are not found in large genetic samples of most population groups. For most mutations, an allele frequency is calculated in different populations, but this information isn’t available for the FOXC2 mutations. The raredisease.org website also states that the prevalence of lymphedema-distichiasis is unknown. [ref]
Note that people can have thick eyelashes without having a double row of lashes.
Genetic variants that cause double lashes:
Check your genetic data for rs121909106 (23andme i5002816 v4; AncestryDNA):
- C/C: normal
- C/T: double lash mutation[ref] increased risk of lymphedema
Members: Your genotype for rs121909106 or i5002816 is .
Check your genetic data for rs121909107 (AncestryDNA only):
Members: Your genotype for rs121909107 is —.
The increased risk for lymphedema can increase the risk of congestive heart failure. If you have double eyelashes, talk with your doctor to see if this is a risk factor for you.
If you weren’t born with double lashes, you can always add some fake lashes ;-) I think Elizabeth Taylor would approve.
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