Most people dream of long, upward-curling lashes to frame their eyes and enhance their appearance. While many resort to eyelash extensions, mascara, growth serums, and lash curlers to achieve this desirable trait, the question arises: where does eyelash length come from? The answer lies in a combination of genetics and environmental factors.
Genes, composed of DNA, act as a code that dictates how our bodies develop and function. Behind every trait, from eye color to mitochondrial function, lies a genetic code. We inherit two copies of each gene, one from each parent, forming a pair. Genes are classified as either dominant or recessive. A dominant gene expresses itself even if only one parent contributes it, while a recessive gene only manifests when inherited from both parents. Dominant traits are more prevalent in the population due to the higher likelihood of inheriting at least one dominant gene compared to two recessive ones.
In the context of eyelash length, there are essentially two variations: long or short. The length, curl, and thickness of your eyelashes is genetic. However, defects are not irreparable.
In some cases, long eyelashes are indeed linked to genetics. While the genetic factors influencing normal eyelash variation remain largely unexplored, a condition called trichomegaly offers insights into the genetics of long lashes. Trichomegaly, defined as eyelashes longer than 12mm, can arise from various causes, including congenital disorders, familial inheritance, acquired conditions, and drug use.
Trichomegaly can manifest as part of congenital disorders or syndromes. For instance, Oliver-Mcfarlane syndrome and Cornelia de Lange syndrome both lead to very long eyelashes, alongside other symptoms. Oliver-Mcfarlane syndrome involves defects in the eye and severe hormone deficiencies, while Cornelia de Lange syndrome presents a range of developmental abnormalities. There are only a few known instances of being born with just super long eyelashes.
Read also: Long Hair and Scalp Health
To understand the genetics of long lashes, scientists have investigated familial trichomegaly, comparing DNA from family members with long eyelashes to their relatives with shorter eyelashes. This research has identified the FGF5 gene as a key player.
FGF5, which stands for "fibroblast growth factor 5," produces a protein that inhibits excessive hair growth, also named "fibroblast growth factor 5." When the FGF5 gene undergoes mutation, it loses its ability to produce this protein.
Each individual possesses two copies of the FGF5 gene, one inherited from each parent. In most people, these copies function effectively, producing the protein that regulates hair growth. However, if both copies of the FGF5 gene are mutated, the individual cannot produce the protein, resulting in continuous hair growth and, consequently, trichomegaly.
Trichomegaly follows a recessive inheritance pattern. This means that an individual must inherit two mutated copies of the FGF5 gene to exhibit the condition. If an individual inherits one mutated copy and one regular copy, the regular copy will still produce the protein, preventing trichomegaly.
A Punnett square can visually illustrate the inheritance of trichomegaly. Let's represent the FGF5 gene with the letter "F." A mutated copy of the gene is represented by "f," while a regular copy is represented by "F."
Read also: Brazilian Wax Guide
If both parents have trichomegaly (ff), all their children will inherit two mutated copies of FGF5 (ff) and will therefore also have trichomegaly.
If only one parent has trichomegaly (ff) and the other is a carrier (Ff), there is a 50% chance that their child will inherit two mutated copies (ff) and have trichomegaly, and a 50% chance that the child will inherit one mutated copy and one regular copy (Ff) and be a carrier.
If neither parent has trichomegaly but both are carriers (Ff), there is a 25% chance that their child will inherit two mutated copies (ff) and have trichomegaly, a 50% chance that the child will inherit one mutated copy and one regular copy (Ff) and be a carrier, and a 25% chance that the child will inherit two regular copies (FF) and not be a carrier.
It is possible for trichomegaly to appear even when neither parent exhibits the condition. This occurs when both parents are carriers of the FGF5 mutation, passing on their single mutated copies to their child.
While genetics play a significant role, environmental factors also influence eyelash length and health.
Read also: Detecting Alcohol Use via Hair Analysis
Eyelash length can change over time, often becoming shorter with age due to alterations in hair growth patterns.
Certain health conditions and skin changes can also affect eyelash length and density.
Harsh styling practices, such as the use of false eyelashes, can damage existing lashes, leading to thinning and breakage. The glue and tension associated with false eyelashes, combined with daily mascara application and curling, can cause long-term damage.
Certain medications can also affect eyelash growth. For example, latanoprost, used to treat glaucoma, and erlotinib, used to treat lung cancer, have been shown to cause trichomegaly. Epidermal growth factor receptor inhibitors are used to treat a variety of solid tumors like bladder, breast, colorectal, head and neck, lung, and ovarian cancers. Acquired eyelash trichomegaly has been reported with topical use of latanoprost. The effects of prostaglandin F2-alpha and latanoprost have been found to stimulate not only murine hair follicles and follicular melanocytes but also the conversion from telogen to anagen phase. This side effect has also been tried for cosmetic effects.
Just like the hair on our heads, eyelashes require proper care to maintain their health and length. Washing and conditioning eyelashes regularly can help prevent breakage and promote growth.
To enhance eyelash length and volume without causing damage, consider using an eyelash conditioning serum. Look for serums containing key ingredients encapsulated with nanosome technology, which allows for deeper penetration into the skin and more effective delivery of nutrients to the hair follicles.
Spectral.LASH Advanced Eyelash Conditioning Serum is an ophthalmologist-developed serum containing ingredients delivered via nanosome technology. It is hypoallergenic, non-irritating, and free of Parabens, Phthalates, BHT, and gluten. It is also oil-free and safe for use with eyelash extensions.
While long eyelashes are often considered a sign of beauty, their primary function is to protect the eyes from particles and debris. Eyelashes act as a barrier, preventing dust, pollen, dirt, and other airborne particles from entering the eyes. They also trigger the eye muscles to close the eyelids when they come into contact with larger objects, protecting the eyeball from injury.
Eyelash trichomegaly is defined as increase in length (12 mm or more), curling, pigmentation or thickness of eyelashes. Eyelash trichomegaly is an uncommon finding that has been reported in association with a wide variety of conditions. Its clinical significance and underlying pathophysiology is yet to be discovered, but factors such as prostaglandins, immune system regulation, and epidermal growth factor receptors appear to be involved. Although it tends to have a benign course, it can lead to psychological disturbances and can result in corneal abrasions and visual disturbances, if trichiasis occurs. The onset of eyelash trichomegaly is an important point for delineating a specific etiology.
tags: #are #long #eyelashes #genetic
